ARE 5.0: PDD

In curtain wall installation: do we install the glass from the inside or outside?

Either. . . Outside installation, called "pressure plate glazing" performs better but is more expensive (scaffolding!) Inside installation, called "interior dry glazing" performs slightly worse, but is less expensive (no scaffolding!)

How do you detail a lintel on an exterior load-bearing masonry wall?

Lintel can be precast concrete, site-cast reinforced concrete masonry block (lintel block or bond beam block filled with rebar and concrete), stone, or metal. It spans the opening over the door or window, distributing the loads around the opening. Lintel must overlap the jamb by six inches so that it has enough wall on each side to bear on. See here. Lintel should have a membrane and weep holes so that the water that moves behind the cavity wall will be properly redirected out of the cavity wall when it meets the lintel. See here. Don't design a point load to fall on the flange (thin, non-structural part, seen here between points B and A) of a metal lintel. It will deform it. Lintels are prone to thermal bridging. Design them so that the inside and outside portions are separate elements or have insulation. See here for an example.

How are ducts supported from the ceiling structure?

Or from straps like this. Or from trapeze hangers like this.

Stick vs unitized curtain wall system?

Stick system: Installers connect glass and frame piece by piece Unitized (also called modular) system: Factories prefabricate large sections of frame and glass, ship them to the site, where they are hung on the building and attached to the other prefabricated sections of curtain wall.

Describe everything water touches on it's way out of a wall cavity, as it moves from the sheathing's waterproof layer to the outside

1. Waterproof layer on sheathing (could be lapped tar paper, lapped Tyvek, peel-and-stick membrane, or fluid-applied waterproof coating) 2. Mastic (asphalt-based goo that seals the flashing to the sheathing). See here for an example. If the structural wall is constructed of CMU, then the flashing may be tucked between courses instead. See here for an example. 3. Metal or peel-and-stick membrane flashing to redirect the water to the outside of the cavity. See here for an example. 4. Weep holes to air the water to the outside. See here for an example. Workers installing rain screen panels to hat channel to create a rain screen with a capillary break.

How many layers of gypsum wall board are required on each face of a two-hour-rated partition?

2 layers of Type X gypsum wall board on each side of the stud (typically) Fire ratings: When in doubt assume. . . . That a one-hour wall has one layer of 5/8" Type X gypsum wallboard on each side of a stud. That a two-hour wall has two layers of 5/8" Type X gypsum wallboard on each side of a stud. That a shaft wall (two-hour) has one super-thick layer (1") Type X gypsum wallboard (called a "liner panel") on one side and two 5/8" layers on the other side. That's because laborers need to install the shaft drywall from the "wrong" side, for instance, on the fourth-floor level of a seven-story shaft. Installing two layers of gypsum board from the shaft-side would require a lot of scaffolding in a tight shaft space.

Describe, in your own words, a 1/4 bend fitting.

A bend is like a long-radius pipe elbow, and bends are measured in fractions of a full 360 degree turn. So a 1/4 bend fitting is a 90 degree pipe turn and looks like this. A 1/8 bend fitting redirects the pipe 45 degrees and looks like this. An elbow turns in a tight radius, meets established dimensional standards, and measures in degrees. A bend turns in a long radius, requires custom fabrication (and can therefore have any dimensions), and is measured in a fraction of a bend. *in practice, plumbers may use bend and elbow interchangeably to describe the same fitting.

Control joint detail

A control joint is a shallow groove in concrete to control cracks from shrinkage.

Why use a flitch beam?

A flitch beam sandwiches a steel plate between two timber beams and bolts the whole assembly together. They look like this. We used to use them because they offer more strength, longer span, shallower beam depth, and increased dimensional stability than timber-only beams. We use flitch beams less than we used to (outside of historic renovation) because they've been partially supplanted by less-expensive engineered wood alternatives (like glulams, see below).

Which better addresses uplift on the roof membrane? An adhered membrane A mechanically affixed membrane (screwed down)

Adhered (less opportunity for gaps to form under it). Kind of. The true answer is a bit more complicated. . . read on only if you want to geek out. The highest-rated roof membranes are indeed adhered. . . . but with some work and an expensive high-strength steel roof deck, we can theoretically design a mechanically fastened system to achieve comparable in uplift performance. . . it's just typically less economical to pay for the beefier deck and pay for the extra labor to drive all those fasteners in.

List the advantages and disadvantages of EIFS

Advantages: Inexpensive: That's why you see it on crappy shopping centers Ornament easy to add (click here): Because EIFS is synthetic stucco over styrofoam, we can glue on ornamental styrofoam and just stucco over it. High effective R-values: continuous exterior insulation eliminates thermal bridging VERY flexible: doesn't require control joints to prevent cracking and does well in earthquakes (EIFS still needs isolation joints when butted against another material or at a building isolation joint) Disadvantages: Doesn't breathe: Moldy in wet climates, unless you ensure a drainage plane behind the styrofoam Easily damaged: High-impact flavors are available, but even those aren't that robust Just generally not that durable for the reasons above, and hated by much of the public as cheap-looking, especially over time

ADA-compliant room name signs: what height above the floor?

An ADA sign might denote that there is an exam room just on the other side of a door. Installation height: Max 60" to top line of tactile text; Min 48" to bottom line of tactile text; anywhere in between is okay.

Expansion joint detail vs a control joint detail

An expansion joint extends the full depth of the building assembly, creating two independent structural elements. When part of the building expands, it won't push on the other. The gaps between the elements are filled by a squishy material (bitumen, fiberboard).

Which type of insulation attracts termites?

Any of the rigid foam insulations attract termites (extruded polystyrene, expanded polystyrene, and spray foam). Polyisocyanurate and open cell spray foam also provide a theoretical home for termites, but those don't do well underground because of moisture sensitivity, so these two typically wouldn't be in play in a termite discussion. Some spray foams even use sugar as a flame retardant! The good news: chemical treatment for termites around the foundation is very effective at keeping them out, even if you have rigid insulation underground.

Name the lock type: Outside is locked by an inside thumbturn; turning the inside lever or closing the door automatically unlocks the outside lever; if you are locked out, an emergency specialized key can get you back in.

Bath/Bedroom Privacy Lock

What is bentonite used for?

Bentonite is a type of self-healing, expanding, durable clay. In construction, we use it for. . . Waterproofing: as the active ingredient in self-healing sheets that resist future puncture applied to foundation walls or injected in a milkshake consistency against a leaky basement wall. Injected as a grout into geothermal wells to maintain contact between the underground tubing circulating water and the earth that will exchange heat with the water in the tubes. See it poured into a geothermal well here.

Unit cost vs unit-in-place cost

Both these terms, unit cost and unit-in-place cost, mean (just about) the same thing. The "unit cost" usually refers to construction cost estimating during design and bidding and "unit-in-place" is a term usually reserved for appraisers estimating the worth of a building someone is looking to purchase, refinance, insure, or account for in an audit. The unit cost method estimates building budgets or construction costs by breaking down the project into smaller parts, estimating the cost of each of those parts, then multiplying that unit cost by the number of parts (units) in the project. In early design, the "units" may be square feet of finished space. One might make an estimate by taking a $600 per square foot guess (unit cost) and multiplying that by the 10,000 square feet in the project to reach a budget of $6,000,000. Later in the design process (PDD world) the estimate is based on more detailed information: the linear feet of pipe multiplied by the approximate installed cost per linear feet of pipe, plus the number of faucets times the average price of an installed faucet, plus. . . . and so forth for the rest of the project. These spreadsheets may swell in length. Unit-in-place cost method does the same thing-separate all the components of a building, estimate the cost of each unit (in cubic feet of concrete, square feet of paint, linear feet of foundation, number of theaters in the multiplex, number of roofs on the campus, or number of exterior doors on the warehouse) and multiply that unit cost by the number of units on the property. . . , then add everything up to reach a total value for a property appraisal.

What are busway, busduct, and cableduct, and when are they used?

Busway looks like this. It replaces wire in conduit for large installations and includes copper or aluminum conductor bars housed in a protective metal casing. Its section detail looks like this (the link might act up and deny you access, and if that's the case just click on the address bar (the URL) and press the enter key to submit a new request for the URL to immediately get through (don't hit refresh because that only resubmits the current request and nothing will happen)). Economically, busway provides an advantage when the following two conditions are met: (1) We want to carry large amounts of current (up to 4,000 amps. . . to put that in perspective, your bedroom circuit probably can handle 10 or 20 amps). So we'll run busway from the basement of a tall building to the elevator machine room on the roof or from an electrical room to the watt-hungry robots on our factory floor. (2) We want to tap into the busway at frequent intervals along its length. So we'll tap into that same busway to provide power to each floor or each robot. Busways replace a single, large-diameter, wire because as diameter increases, the conductor becomes less efficient. The flat bars inside a busway can carry more power with less resistance and are less likely to heat up than a thick wire or bunches of thin wire. Further, tapping into a big wire or collection of wires at each story (or at each robot) requires significant labor to manually create conduit takeoffs. Plugin busways allow for easy connections (and later, disconnections). See this data center. "Busduct" is simply another word for busway. Cableduct (also called cablebus) looks like this and is just what you think: rigidly mounted insulated cable (instead of bars) running inside the same type of protective metal duct housing. The duct for cable duct is ventilated because cables running in free air can carry more current than cables stuffed into conduit. Relative to busbar/busduct, cableduct is more rare because of its bulkiness and difficulty with tap-offs.

Materials with low embodied energy

Cellulose and glass fiber insulation Wood (depends on what powers the kiln and whether you include the loss of the carbon-removal capabilities of the tree that was cut down) Gypsum board and plaster Rammed earth

Name these valves

Check, globe, gate

Name the lock type: A key locks/unlocks the room from the outside; the inside lever automatically retracts the latchbolt for egress.

Classroom Lock

Name the lock type: A key locks/unlocks the room from the outside and the key also locks/unlocks the room from the inside; the inside lever automatically retracts the latchbolt for egress.

Classroom Security Lock

Where do you locate overflow scuppers?

Code requires one overflow scupper for each (potentially clogged) roof drain, located in plan as near as possible to the roof drain it is responsible for backing up. I'd memorize that. See what I mean here. In practice, the bottom sill of a parapet scupper typically sits two inches above the roof's surface, ensuring not more than two inches of ponding water if the drains clog. Scuppers must measure at least 4 inches high and have a minimum width equal to the required circumference of the roof drain they are backing up. Code mandates a minimum roof drain size based on the amount of rainwater the drain's catchment area can be expected to see in a storm event. You've calculated (and you will again calculate) this in other parts of the course, looking at code rainfall maps, determining a near-worst-case volume of water falling per hour on the horizontal projection of a catchment area, converting that volume of water from cubic feet to gallons and from per-hour to per-minute. . . and finally, selecting a roof drain, gutter, or downspout size from a table that rates drainage system component sizes in gallons-per-minute flow capacities. There are sometimes fewer steps to determining drain size, so be alert to what units are used for the drain size table. There are also different tables for horizontal gutters, vertical downspouts (both on the roof's perimeter), and roof drains (somewhere in the middle of the roof's surface). There are two types of scuppers: (1) scuppers part of the primary drainage system, useful after an everyday rain event to carry the water off the roof and (2) scuppers part of the secondary drainage system used as emergency "release valves." The second kind in this test item are holes in the roof parapet to prevent dangerous ponding on the roof that might overload the structure should the primary drainage system fail. You can see each kind, adjacent to one another, on this wall. If you see water coming out of an overflow scupper, you may have an urgent invisible problem (clogged drains and heavy ponding water that might collapse a roof)! This flashcard question asked about the secondary drainage/overflow kind of scupper, so we can assume it will be useful only if the primary roof drains fail. For a low-sloped roof, the primary roof drainage may be either a scupper with downspout or a roof drain, and the overflow roof drainage may also be either a slightly-higher scupper with downspout or a slightly higher roof drain

Where CAN'T you locate an electrical panel?

Code requires three-feet clear (30 inches wide, six feet high) in front of a panel, so not in very small rooms. The clearance requirement may be bigger for higher voltages. Must be mounted below 6′-7″ Not near easily-ignitable content (i.e. clothes closets) Not in (residential) bathrooms Not over a stairway Not in janitorial closets

What is mastic?

Construction adhesive and sealant

You already know that code requires GFI outlets in bathrooms, kitchens, and outdoors. Where else are GFI receptacles (or circuits) required (that is non-obvious)?

Crawl spaces, basements, garages, hot tubs, laundry areas, occupied rooftops (each might be wet!)

What is the difference between a curtain wall and storefront?

Curtain wall: glazing system hangs like a curtain to create the exterior skin of a building, outboard of the floor slabs. Often multiple stories tall (multi-span); higher design wind pressures. More expensive Storefront: aluminum and glass framing system that sits inboard of floor slabs. One story (single span) max, often for the first floor only in commercial construction. Less expensive. Crews erect and glaze both on site; curtain wall can be unitized in the shop and field-erected. Either one can be reinforced with steel In the framing cavity if loads are excessive.

You already knew that code requires GFI outlets in bathrooms, kitchens, and outdoors. Now you also know they're required in crawl spaces, basements, and garages. Where are GFI receptacles (or circuits) NOT required (but you might think that they would be)?

Dishwashers and other non-counter kitchen appliances (protection is generally required only for counter applications) Hot water heaters (not many people spend much time near them) Attic (it seems like attics should require protection because other auxiliary spaces like crawlspaces do. . . but there's not much risk of standing water in an attic, nor are there many people spending time in an attic.) And of course, living rooms, bedrooms, dining rooms, etc. don't require GFI (sometimes called GFCI for ground-fault CIRCUIT interrupter)

Non-load-bearing exterior walls may require a fire rating. The type of fire rating (one hour, two hours, etc.) is based on the _______.

Distance between your building and the property line The fire rating of exterior walls is based upon fear that your fire will spread to the adjacent buildings. It is determined on Table 602 "Fire Resistance Rating Requirements for Exterior Walls Based on Fire Separation Distance." Besides the distance to the property line, the fire rating of the exterior wall is governed by the construction type (non-combustible concrete buildings can sometimes have a lower fire rating in the exterior wall); and further controlled by occupancy type (high- and medium-hazard buildings, factories, and retail (with lots of content to burn) may require more fire-resistant exterior walls). See here (and scroll down to Table 602). Load-bearing exterior walls must also comply with the fire ratings set forth in Table 601. Those parameters serve a different purpose: not so much to prevent fire from spreading to the neighbors, but rather to make it less likely that your building will collapse once on fire.

Which is better, face-sealed EIFS or drainage EIFS

Drainage EIFS is much better! Exterior finish and insulation systems (EIFS) are the kind of synthetic stucco exterior finish that you see in new sunbelt homes and shopping centers everywhere. It looks like this. Click here to see an EFIS fail (maybe a basketball hit it?) that illustrates the thin coat of stucco over Styrofoam that characterizes the product. In the 80s, builders started installing EIFS (pronounced EE-fiss) on residential projects. Because residential projects often have organic materials (wood studs, cellulose insulation), and because the EFIS was "face-sealed" without either a drainage plane capillary break behind it draining to weep holes or a rain-resistant layer on the exterior sheathing, trapped water didn't drain and mold grew. The problem was especially acute in humid and marine climates (think Outer Banks, North Carolina). The 90s saw so much EFIS mold litigation that even obtaining an insurance policy on an EFIS building became prohibitive. The solution? Add a drainage plane behind the insulation and in front of a lapped layers of building felt or house wrap. The new assembly is called "drainage" EIFS, it has become the standard, and the mold litigation industry no longer plagues EFIS construction. To read more, go here. Face-sealed EIFS "stucco" wall (above) Drained EIFS "stucco" wall (above) An enrollee sent me this photo of the EIFS on his house in Southern California. Nearly all of the EIFS legal disputes I know of stem from the 80s and 90s in southeastern and gulf-coast wet climates before folks there discovered drained EIFS, but an enrollee took this image of his recently-built California house and just emailed it to me. Because the SoCal weather is so dry, the builders probably didn't establish a tradition of building with drained EIFS. . . but this house is a five-minute walk from the Pacific Ocean, so the air there remains humid year-round! (And cool too; he told me that despite Irvine's hot weather a few towns over, he almost never runs the A/C but runs the heat for several months of the year.) Rainwater wiggles its way in, but never drains, so eventually, trapped moisture comes back out on dry days through the backside of the paint, pushing up paint bubbles. The homeowners filed a suit against the builder that's still pending as I write this. North-facing EFIS often accumulates mildew: If you start looking for it, you'll see damaged EIFS everywhere: In response, manufacturers began offering "impact-resistant EIFS," more durable than standard EIFS, but still not as robust as other claddings. Because of this impact issue, you'll often see the first floor clad with a tougher material, then EIFS up higher.

Name the lock type: The door is unlocked by a key outside; the outside lever is continuously locked by 24 volt AC or DC current; an electrical switch or power failure unlocks the door remotely; the inside lever automatically retracts the latchbolt for egress.

Electrically Locked (Fail Safe)

Name the lock type: The door is unlocked by a key outside; the outside lever is continuously locked but can also be unlocked by a 24 volt AC or DC current; an electrical switch unlocks the door remotely, but in a power failure, the remains locked; the inside lever automatically retracts the latchbolt for egress.

Electrically Unlocked (Fail Secure)

When do we use ethylene glycol in a cooling system?

Ethylene glycol is used as an antifreeze mixture for the refrigerant in the lines. It also makes the refrigerant less viscous and therefore easier to pump. We can thus transport refrigerant at lower temperatures and still keep the mixture flowing (and not becoming ice). Remember I mentioned that there's a limit to how far the outdoor compressor can be from the indoor evaporator in a split system (60 to 100 feet)? Adding ethylene glycol can extend that range, especially in cold climates. Read on only if you want to geek-out or design food processing plants for a living (not required for your studying): Ethylene glycol is toxic if ingested so should be avoided if there is the slightest chance it could leak into drinking water or food processing systems. In those cases, propylene glycol is used instead. This is especially common in specialized industrial processes where we may need something to be VERY cold as part of the manufacturing process itself: brewing, milk production, pharmaceuticals, cosmetics, some specialized chemicals, etc.

How do we prevent the brick or stone from crushing itself under its own considerable weight in mid-rise or high-rise masonry buildings?

Every few floors, we support the masonry veneer with continuous steel angle tied to the structural wall behind. Click here (and note the need for flashing and weeps to allow for water in the airspace cavity behind the masonry to escape)

What is the difference between internal and external metal roof flashing?

External roof flashing is laid on top of shingles in valleys and along peaks. Internal flashing is installed under the roof shingles. Counterflashing (or cap flashing) is the first line of defense when shedding water off a parapet. It attaches to parapet wall with sealant (to prevent water from penetrating behind the flashing) and laps the step flashing. In high wind applications, use flashing with clips so it doesn't rip off the wall.

When do we require a. . . Fire wall Fire barrier Fire partition

Fire wall: An independent structural wall that extends from foundation to (or through) roof. We use it to make one building into "two" buildings so that if fire causes a collapse on one side, the other side won't collapse. We see these separating townhomes. Click here for an example. here too. Fire barrier: Runs continuously from the structural deck below, through the dropped ceiling, to the structural deck above. We use it to protect our egress path and shafts from the rest of the building. Click here for an example. This is the one that the exam likes to test you on the most. Fire partition: Also runs deck to deck-or stops at the ceiling, provided the ceiling is also fire rated. We use these to separate tenants in a building. Why do we care if the partition can stop at the ceiling? It allows us to run sprinkler pipes, other water pipes, ducts, and conduit above the ceiling from room to room without having to carefully penetrate a sealed deck-to-deck fire barrier. We can build a fire-resistant box-in-a-box room within a building. See here for an example. Each of these will have flavors that are rated 1-hour, 2-hour, 3-hour, etc.

Fire stopping vs fire safing

Fire-rated walls and floor-ceiling assemblies need a way to maintain their air-tightness at joints and duct/pipe/conduit penetrations. Fire stopping: all the systems used to seal those small gaps and maintain the fire rating of the assembly Fire safing: one of the types of fire stopping, it is a fire-resistant mineral wool insulation material that can stuff a gap to maintain the fire rating, like this. See this excellent short video. Though the two terms are used interchangeably in the field, I think NCARB may think that fire safing is always mineral wool (or similar) stuffed in large openings like this. And that firestop is the putty used for small cracks like this. One way to think about it: fire safing is like backer rod and firestop is like caulk.

Flashing and sealing where the parapet meets the roof

Flashing and sealing where the parapet meets the roof. The counterflashing allows the roof membrane to be replaced more easily.

Draw a window section detail for a masonry wall

For masonry wall

Draw a window section detail for a stick-built wall

For stick-built wall

What is the difference between ground fault interrupters (GFI) and arc fault circuit interrupters (AFCI)?

GFI switches the circuit off in the presence of water and GFI receptacles or circuits and code requires their use outdoors, laundry areas, garages, crawl spaces, basements, kitchen counters, and anywhere within 6 feet of water. They are not required for dishwashers, water heaters, or attics. Arc fault interrupters switch the circuit off in the presence of static electricity from a billowing curtain, or from a nail from a picture-hanger hammered through a wall that accidentally strikes a hidden wire, or from furniture smooshed against a plug that damages the prongs. Code requires arc fault interrupters for circuits or at receptacles in residential construction (not required in unfinished basements or garages). For photo examples of common wiring conditions that arc fault circuit interrupters intend to protect you from, click here (after viewing it, you'll want to pull your couch away from your wall a bit). Both GFI and arc fault interrupters monitor the current in a circuit or at a receptacle and switch off in the presence of an unexpected electrical flow imbalance. GFI primarily protects against electrocution from water; arc fault primarily prevents fires from instances where wire damage puts the hot wire in contact with the neutral wire or ground wire and a resulting short-circuit heats up the wires.

How does geothermal (energy production) differ from geothermal (heating and cooling)

Geothermal energy production: brine-water solution in natural magma-heated hot-water springs is pumped up to the surface to spin a turbine which generates electricity at the utility (rather than at the building) scale. Carbon-free and renewable, but obviously available only in places with active hot water springs. Provides fully 6% of California's energy production and promises future growth. Geothermal heating and cooling: water solution is pumped from the evaporator (or condenser) underground and back again to make an AC system much more efficient because soil underground is warmer than the air in the winter and soil underground is colder than the air in the summer. This doesn't work in extreme climates because. . . . If the climate is always hot, the building will be cooling (almost) all year, continually depositing the building's heat into the ground, heating up the ground over time, and eliminating the advantage of using the ground to temper the hot air. Likewise, If the climate is always cold, the building will be heating (almost) all year, continually depositing the building's coolth into the ground, cooling down the soil over time, and eliminating the advantage of using the ground to temper the cold air. It seems crazy to me that our AC system can quasi-permanently change the temperature of the soil! So geothermal AC systems work best when the heating load and cooling load of a building are nearly equal.

Why would you fill a hollow CMU?

Grout: easy-flowing cementitious material poured into a CMU wall from the cavity openings in the top every four feet as the wall goes up. Used for compressive strength, horizontal rebar and vertical rebar added for tensile strength. Used for load-bearing walls (including those that resist seismic). Hollow: CMU cells with air are better insulators than grout-filled, but obviously weaker than grout-filled reinforced block. Vermiculite-filled: loose granular mineral stuff poured into the cavities for increased thermal resistance, increased sound transmission loss, and improved fire rating (performs better than air in all three). In older construction, vermiculite may contain asbestos. Perlite- filled: loose granular stuff poured into the cavities; looks like small packing peanuts, if small packing peanuts were made from stone. The process for making perlite: volcanic glass is mined, then heated until it pops like popcorn, so it has tiny air pockets each of which is a good insulator. Used for increased thermal resistance (slightly better than vermiculite and meaningfully better than air). Polystyrene bead insulation: Styrofoam beads poured into the top of a CMU wall. Used as insulation. Injection-foam-filled: increased thermal resistance (insulation). Can be injected from either the inside or the outside and doesn't need to be poured in from the top so it can be used in renovations where the top of the wall is not accessible. Vermiculite, perlite, and polystyrene beads pour out of the wall like sand if you need to cut into the blocks for any reason after they've been filled. Injection-foam-filled CMU doesn't have this problem. Plus with vermiculite, perlite and polystyrene beads, you don't really know if the granules have made it down to all the cavities below (what if there was a clump or obstruction and some of the cells went unfilled?). Here, foam is injected into multiple holes in the wall, so you know each cavity is filled. These closed-cell foams also serve as an air barrier.

Inverse Square Law

In a free field, every time we double the distance from a lighting source, the light level drops by 4.

Delayed egress locking systems

In retail, these delayed door panic hardware systems prevent shoplifters from running out of the emergency exit because an alarm sounds and the door doesn't let the perp out of the building for 15 seconds after they lean on the hardware bar (30 seconds when an exception is granted). Delayed egress locking systems can also be used for other security-sensitive applications such as airports, warehouses wary of employee theft, and nursing homes fearful of wandering dementia patients. They are only permitted in buildings outfitted with sprinkler systems or automatic smoke or heat detection. That way, when the automatic sprinkler system, smoke detection system, or heat detection system is activated, the delay in the system that prevents fleeing occupants from immediately exiting is deactivated automatically and occupants can easily leave without waiting in a real emergency. The delay also can be deactivated by a loss of building power or manually by the fire command center. Delayed egress systems are not permitted in occupancy groups A (assembly): we don't want the first occupants out of a burning theater to be crushed against a door that won't open by the panicked pushing of those fleeing behind them. E (K-12 education): I don't know if this is school-shooting-related, or, like the assembly exception, related to the potential for crushing and trampling. H (high hazard): You need to be able to get out of the gunpowder factory without ever waiting 15 seconds. In each exception, the possible security benefit of the delay is outweighed by the life-safety benefit of easy exit. In I-2 (detox facilities, psych hospitals) and I-3 (prisons) a second (but not a third) delayed egress door is permitted as part of the egress path.

Incidental use vs. accessory use in the code

Incidental use example: An accountant's office (occupancy class B) includes a boiler room or other space that poses a greater life-safety risk than posed by the office. Provided that the boiler room does not exceed 10% of the story's floor area, the boiler room can be counted with the office in the less-stringent B-classification. . .but the more dangerous boiler room requires fire separation in the form of fire-rated walls and floor-ceiling assemblies (and/or sprinklers). It is not up to the architect to decide what can be considered incidental use (though it used to be in older code versions). Rather, the code maintains a list of such high-risk-but-small-area rooms it considers "incidental," such as refrigeration equipment rooms, laboratories, paint shops, and large laundry rooms. Accessory use example: An accountant's office (B) includes some storage (usually S, but not considered separate here). If the storage is for the accountant, and not on the list of small-but-risky incidental use spaces, and less than 10% of the floor area of that story, it doesn't require a fire rated wall separating the storage area from the office around it. *Accessory occupancies are individually classified. However, in the case of accessory storage spaces per section 311.1.1 in the IBC, they'll be classified as part of the occupancy they are an accessory to.

Warm heating air rises to the top of a tall room in the winter. But the people who need the heat are standing on the floor. What to do?

Install a fan in the ceiling to mix the air. Most ceiling fans have a bi-directional switch: blow downward in the summer when moving air helps cool occupants, and draw air upwards to generally mix the room air without blowing on occupants in the winter. Stratification is a big problem in high-ceilinged rooms, especially if there's a mezzanine. Do we make it comfortable for those on the main floor but too hot for those on the mezzanine? Or do we make it comfortable for those on the mezzanine, but cold for those on the main floor. Plus, if the hot air in the room hovers near the ceiling, that's an inefficient way to heat, perhaps wasting about 20% of the room conditioning energy. Note the ceiling fans on the top of this large atrium. This large-diameter fan on the ceiling of a basketball arena mixed air during the winter. The upper seats where I was sitting were uncomfortably warm, so the fans went about mixing the air to get some of that hot air to the folks courtside.

Does duct lining quiet a duct?

Internal duct lining quiets fan noise moving through ductwork a LOT (but has air quality concerns from (1) mold growing in the fibrous dark liner and (2) particulates from the fibrous lining fibers blowing loose and swirling around the room and in your lungs) External duct lining fails to quiet a duct Flexible duct: If the last 3 to 12 feet of a duct run is swapped for flexible duct (which also allows tolerance for diffuser placement) it will quiet AC noise. The research suggests flexduct makes the room moderately quieter. . . but my experience tells me it often makes the room much much quieter.

Which is less expensive to install: aluminum or copper?

It depends. Aluminum's advantage is that it weighs less (cheaper to install for large buildings); copper's advantage is that it's smaller for the same current capacity (cheaper to install for small buildings). Copper is almost always used in residential branch circuits because it requires less skill for homeowners to safely work with. If exposed aluminum wire isn't immediately treated, it will develop an oxide film that may heat up later and seed a house fire. Of course, the prices of copper and aluminum, as all metal commodities, fluctuate wildly, so at any given time, external market factors may push a finger on the scale to make one less expensive than the other. Click here to see what happened to two prices in 2006.

What is a lag screw? A lag bolt?

Lag screws use hex head or square head screwdrivers. They look like this and require tool heads like this or this. Lag bolts taper and are threaded like a wood screw and therefore don't need washers or nuts. They look like this. A wrench drives them.

ADA-compliant room name signs: location

Location: Latch side of single door; inactive leaf of a double door with an inactive leaf; to the right of the right-hand door of a double door with two active leaves; if there is not enough room next to the door, you may place the sign on the nearest adjacent wall.

Materials with high embodied energy

Manufactured with high heat: Ceramics Glass Stainless or galvanized steel Concrete (but, because of its weight, can look on tables like it has low embodied energy when measured on a per-kilogram basis) Manufactured with intense chemical processes and petrochemical use: Epoxies/Resins/Formaldehyde/many adhesives Paints and stains Foam insulation (polystyrene, spray-foams, polyisocyanurate) Plastics/Vinyl/PVC/melamine/polycarbonate Engineered wood products (MDF, Glue-lam) Manufactured with intense mining processes: Copper Aluminum Stone

What is CSI Masterformat?

Masterformat is a system for organizing construction documents, specs, contracts, and operational manuals. Published by the Construction Specification Institute (CSI), it allows, for instance, a fire sprinkler subcontractor to easily find the relevant sections of a building's documents so a requirement is less likely to be overlooked when bidding, purchasing a product, or during construction. There are 50 numbered divisions, ranging from Instructions for Procurement (found in Division 01) to Fire Suppression Sprinkler Systems (found in Division 21). Masterformat is especially useful for systematizing spec writing, as specifications may easily reach thousands of pages in length in a medium-sized building project. When using Masterformat—which is typically, though not always, utilized on a medium-sized or large project—know that the table of contents alone is nearly 200 pages! If the drawings are the broad intention of a building, specs act as the fine-print, establishing the scope of the work, the materials and methods of construction to be used, and the quality of the workmanship expected. Spec-writing is important to the project, though tedious. Some firms write their own specs in-house, and others hire a professional architectural spec writer. Once a thriving category of consultancy, human spec writing is now waning, gradually being replaced by digital tools: Google searches or links to product information within a BIM file.

Mastic and weep holes in the shower

Mastic and weep holes are also in shower assemblies, which can be confusing, because those terms are used with flashing in cavity walls. Weep holes are found in shower drains as alternative paths for water to move down the drain. They allow under-floor water that has seeped through the tile grout and joints to find its way back to the drain. See this video. Tile mastic and thinset are the two most common options for affixing tile. Mastic, originally an organic resin from a Mediterranean plant, is now a catch-all term for sticky stuff that dries quickly (useful for affixing vertical tile so it doesn't sag while drying). Mastic, as applied to tile laying, is a term that has largely been phased out and replaced with "fast-grabbing tile adhesive," "no-sag tile adhesive," or just "tile adhesive." Thinset is a cement product. It takes longer to set, which can be a good thing, or a bad thing, depending on whether you want the tile to stay put without having to hold it for a while, or you want the flexibility to reposition the tile later. Thinset can also be used to lay vertical tile, but is always used to set horizontal tile in showers. Unlike mastic, which can get damp and still hold, thinset can remain submerged in water and still perform. So, to get the terms straight. . . "Thinset" and "mortar" and "thinset mortar" are interchangeable terms. Like the stickier "mastic," which is interchangeable with "adhesive" they are what hold the tile to the floor, ceiling, wall, or backsplash. Grout is the stuff that fills in the spaces between tiles. Grout, which is also a cement product, but one with a different chemical mixture than thinset mortar, provides additional tile bonding and protects the edges of the tile from chipping. It is used always between the tiles, regardless of whether the tile was affixed with thinset mortar or mastic adhesive.

A horizontal wind force of 3,840 pounds is acting on a wood shear wall with a uniform gravity load of 1,000 pounds per linear foot on top of the wall. The wall height is 35' . Calculate the minimum length of the wall so that it will still behave as a shear wall and resist the lateral loads.

Minimum length of 10' As shear walls shrink in length and get taller, they behave more like columns and less like shear walls-and are unable to resist lateral loads from wind or seismic forces. We need to establish a maximum aspect ratio for tall, thin, shear walls, beyond which the panel action of the wall in resisting horizontal loads can no longer be trusted to stabilize the building. The gravity load on the top presented in this problem isn't relevant to this calculation. Prescriptive code requires a maximum shear wall aspect ratio (height:length) of 3.5:1, provided the shear wall is made of something stiff (like structural fiberboard). This maximum drops to 2:1 for a less-stiff wall (like blocked particle board), so if the shear wall were less-stiff, our minimum wall length would be one-half of the 35' height, or 17.5'. With a stronger wall assembly, we can get the wall thinner: 3.5:1 or 10' long, which is our answer. When using the prescriptive code, the horizontal force is also redundant. The above are based on rules-of-thumb. There are at least three different math-based alternatives to calculate the minimum length if the wall has openings for windows/doors, but for a basic un-perforated wood wall, we can simply divide the horizontal wind force of 3840 pounds by 320 pounds/foot to derive a minimum wall length of 12 feet. Where did the 320 number come from? You'd need to look it up in a table (not given in this problem) defining allowable shear forces for different constructions. This is likely beyond what the ARE would ask of you, but I include it here for those who are curious. In practice, a shear wall in wood construction is almost always built as follows. OSB on one side of the exterior stud wall (that doubles as enclosure sheathing) with horizontal blocking framed so the OSB edges have something to nail into: that way when the wall is pushed horizontally, the free edges of the OSB panels won't buckle. Framers nail the perimeter of the OSB six inches on-center and the middle of the OSB at 12" O.C.; and they affix hold-down anchors at the ends of each segment so that the wall doesn't peel off the foundation when exposed to the lateral loads that the wall intends to resist. Code limits masonry shear wall aspect ratios (height:length) to 2:1, and concrete and CLT have aspect ratios defined by other tables and calculations.

Circuit A is 240 volts and 4000 watts Circuit B is 120 volts and 500 watts Which circuit needs a thicker wire? Given: W=I*V

More current (measured in amps and denoted by "I") needs thicker "pipes" (thicker wire). If the wire isn't thick enough, it becomes hot and can start a fire.

What type of rubber should your gasket be made of?

Natural Rubber: Strong but breaks down quickly in sunlight Styrene-Butadiene rubber (SBR): less expensive but not as strong nor resilient over prolonged pressure EPDM: most water resistant (also used as roofing membranes), resistant to abrasions and tears, stands up to weathering and breakdown from sunlight exposure, and maintains resilience over prolonged pressure. Silicone: Also resists breakdown from sunlight exposure and maintains resilience over prolonged pressure. Has a longer lifespan than EPDM, more stretchy, and much better in locations where it might get hot (EPDM can fail at 130 degrees). Each rubber breaks down when it gets too hot and each becomes brittle when it gets too cold.

Are fire-rated barriers (walls or floor-ceiling assemblies) required between "nonseparated" occupancies?

No (not usually). If two occupancies are considered nonseparated, the barriers between them needn't be rated unless they are dwelling units (apartments), sleeping units (hotels) or similar residential (R) classifications-which do require fire-rated barriers. And as is often the case, prisons (I) and fireworks storage facilities (H) are also exceptions-and also require fire-rated separation.

Define nonseparated occupancy vs separated occupancy in the code

Nonseparated occupancies example: We'll use the same accountant's office (occupancy class B), but this time the storage area (S) exceeds 10% of the story's floor area or the storage area is used not by the accounting office, but rather by the landlord, who has an eBay business and likes to keep his merchandise in the storage room. For either of these reasons, we can't classify the storage area as an accessory space. We have two options instead. We can deem them "nonseparated" B and S occupancies, or we can deem them "separated" B and S occupancies. The nonseparated flavor often, but not always, allows for a less expensive alternative. You typically wouldn't have to design fire separation between the B and S areas in nonseparated construction, however when you determine area limits, height limits, and construction type, you would have to treat the whole building as if it were the more restrictive of the two occupancy types. In this case, the whole building's construction type might have to be designed to a higher S standard, instead of a lower B standard. Separated occupancies example: Here, again, the storage area exceeds 10% of the floor's area or someone other than the accountant uses the storage area. We have the option of declaring the B and the S as "separated" occupancies and, as such, we may have to build fire-rated walls and floor-ceilings between them. The B and S areas each comply with the code based on their respective occupancy classification. Construction type here (and area limitations) would be based on the proportions of the building that fall under each type of classification. You can see how this may, or may not, work out to your advantage. In some cases the cost of building fire separation within the building's different occupancies exceeds the cost of the limitations on whole-building construction type (and you'll choose to pursue nonseparated occupancy status); in other cases the cost penalty of within-building fire separation pales relative to limitations of whole-building construction type (and you'll go with separated occupancies instead). In short, either don't separate the rooms and build the whole building to the more strict standard, or separate the rooms and build each part of the building to its own standard.

Name the lock type: A key outside or inside thumbturn locks/unlocks the outside lever; the inside lever automatically retracts the latchbolt for egress.

Office and Inner Entry Lock

Why does the R-value decrease if we make our 3-inch airspace thicker?

Once the airspace exceeds 4 inches in thickness, we develop a convective loop. What's that? In wintertime, the inside surface of the airspace is much warmer than the outside surface, and you know that warm air rises and cold air sinks, so air drops down the cold outside surface and rises back up the warm inside surface. It's not like we develop tornadic wind speeds inside the airspace through these mild natural convective loops, but the air movement is enough to accelerate (rather than insulate) the transfer of heat from inside our building to the atmosphere outside, nullifying (or even reversing) the modest insulative value (about R-1) of an airspace. If you'd like to see an image of this phenomenon, click here. NCARB doesn't know this, because it can't be found in MEEB, but you may want to know that the 4-inch threshold will vary based on the height of the airspace. Very tall airspaces may form convective loops at narrower thicknesses.

What is panic hardware? Where is it required?

Panic hardware allows throngs of scared people to run into a door. . . and the door opens from the pressure on a bar, without turning a lever. You've seen it a million times, and it looks like this. It is required in assembly, educational, and high-hazard occupancies with an occupant load of 50 people or more.

Name the lock type: door that never locks, like when you need to maintain egress

Passage Latch: The latch bolt is retracted by the lever or knob from either side, always (lever meets accessibility and knob doesn't, but the knob is drawn here for clarity)

Define: Bending stress Bending moment Section modulus Modulus of elasticity

Picture a fully-loaded beam Bending stress: how much the bottom of the beam center wants to split apart Bending moment: how much the beam wants to "smile" when loaded Section modulus: how strong is the shape of the beam Modulus of elasticity: how strong is the beam's material (steel, wood, reinforced concrete)

Which pipes create less friction? Copper Plastic Steel

Plastic

Which type of pipe expands more when hot water flows through it: Metal or Plastic?

Plastic

A distributed array sound reinforcement system requires a time delay on its speakers to _______. Limit the range of frequencies Limit the range of loudness Prevent feedback Preserve the perceived aural location of the sound source

Preserve the perceived aural location of the sound source How do we ensure that loudspeakers in a low, long room, sound "right?" We put the ones in the back on a delay so that the unamplified sound from the person speaking arrives at the listener before the amplified sound from the nearby loudspeaker. This creates a more natural sound and preserves the sense that the source of the sound comes from the front of the room.

Put these types of curtain walls in order from most- to least-reliable when keeping out rainwater: Face-sealed Pressure-equalized rainscreen Water-managed

Pressure-equalized rainscreen, Water-managed, Face-sealed

What are the pros and cons of metal halide lamps?

Pros: Efficient, Long life; Bright (for high bays, big-box stores, factories, stadiums, and parking lots) Cons: Long start times; Glare (for small rooms); So-so color rendition If you forgot what metal halide fixtures look like, go here. The left side of the gym is LED and the right side of the gym is metal halide.

What are the pros and cons of incandescent lamps?

Pros: Exceptional color rendition (chartreuse on the painting looks chartreuse to the eye); Interchangeable (if it looks like it screws in to the socket, it will work in the socket) Cons: Inefficient! . . . about six times the power input required for the same amount of light output, relative to each of the lamps on the next few flash cards; Heats up the building *halogen is a type of incandescent that burns whiter (less yellow), and most new incandescent lamps are actually the halogen flavor because they burn about 25% more efficient than traditional yellow incandescents.

What are the pros and cons of fluorescent lamps?

Pros: More efficient than incandescents; longer life than incandescents Cons: So-so color rendition; don't work in cold outdoor applications

What are the pros and cons of LED lamps?

Pros: Very long life; Much more efficient than incandescents (about the same efficiency as fluorescents and metal halide); Improving every year (the future of almost all lighting applications) Cons: Don't work well unless they can conduct heat away from the electronics (that's why the fins) so may not work as a retrofit in your existing fixtures if those fixtures trap heat See here for a comparison. The "CFL" label in the image stands for compact fluorescent lamp, a type of fluorescent with a built in ballast so that it can screw into a incandescent fixture.

Wood frame shear walls

Short segments may need steel to make them stiffer Blocking is required so that OSB panel edges have something to nail into Hold-downs are required at ends of shear walls (or ends of shear wall segments if shear wall is perforated with windows or doors) to resist uplift forces, which are a result of the overturning (moment) force. Anchor bolts between the hold-downs carry the shear force. (In practice, a really tight hold-down will provide some shear resistance, but the main purpose is to keep the tension side of the shear wall from lifting)

How do you separate floors with different occupancies in mixed use buildings? IBC Section 508 addresses mixed uses and occupancies. Sometimes different occupancies within a building are considered by the code to be "separated" and sometimes they are considered to be "non-separated." We achieve separation with a fire-rated wall or floor-ceiling assembly. See the table. The "S" column is used for sprinklered buildings and the "NS" column is for buildings without a sprinkler.

Sometimes there is no fire-rated barrier required by the code to separate different occupancies. This is indicated by an "N" in the cell that aligns with the two different occupancies under consideration. For instance, looking across the first row of the table, there surprisingly appears to be no fire rated separation requirement for a theater (group A-1 "assembly" occupancy) that shares a wall with foundry (group F-2 "factory industrial low-hazard" occupancy), provided that the building is sprinklered. If the building is not sprinklered, there would be a requirement for a one-hour-rated wall. There are of course other, acoustic, reasons why these two spaces shouldn't share a wall. Some adjacencies are not permitted no matter how fire-resistant the wall or floor-ceiling assembly is constructed. These have an "NP" in the cell. This is the case with a parking garage (group S-2 occupancy) below a drug detox medical facility (group I-2 occupancy) in a building without a sprinkler system.

Specifications vs MasterSpec vs UniFormat vs the project manual

Specs (short for specifications): the fine print of your project. What gaskets may be used on the exterior doors. Developed by the architect, and the contractor is bound by what's in there. MasterSpec: Created in the 60s, it established a standard for ordering specs. . . a glorified, but useful, table of contents. . . what the Dewey Decimal System is for library books, MasterSpec is for specifications. . . .proprietary (created by a for-profit company) but created for the AIA, so it has wide acceptance and is fair game on the exams. . . the painter doesn't need to look through 1,000 pages of specs to find out if he is allowed to paint the exterior today, despite the 49 degree temperatures outside. He knows just where in Masterspec he needs to go. UniFormat: a competitor to MasterSpec. MasterSpec organizes the specs by material (sepcs on stone, specs on wood, etc.) and Uniformat organizes by system (specs on damp proofing, specs on spread footings) Project Manual: Specs are a major part of the Project manual. The project manual also includes bidding requirements and contracts.

Describe the difference between the following types of specifications: Performance Prescriptive Proprietary (closed) Proprietary (open) Reference Descriptive

Specs may be written in different formats, but are typically written as a combination of the following: Performance-based specs describe the way the product will perform without calling out a specific manufacturer, for example, "fasteners must be able to withstand a wind load of 110 mph." Prescriptive specs describe the construction means and methods, for example, the composition of the concrete mix. Closed Proprietary specs name the specific manufacturer, and don't allow substitutions, for example, "CR Laurence Co Double Seal Spacers, in dark bronze and with a dual seal, catalog number 3455590 shall be used at stairwell windows" Open Proprietary specs also name one product from one manufacturer as the basis for design, but they allow other products as acceptable substitutions. Substitutions are processed through the General Requirements substitutions procedures in Division 01 of the spec set. Reference specs demand the product or installation meet the requirements laid out by a trade association, government agency, or other industry reference standard, for instance, "Scaffolding must meet requirements as laid out in ANSI ASC A14.2," or, "Clay brick conservation treatment must meet requirements as established in the National Research Council Canada National Master Specification, section 04 04 21.19." Descriptive specs are a hybrid of performance and prescriptive specs. They describe the way the product will perform without calling out a specific manufacturer, but are likely to also include clauses detailing specific means and methods of construction. For instance, a descriptive specification might both establish the strength of the mortar, and establish the water ratio in a mortar mix to be used. *Often specs fall into more than one of these categories. For instance calling out a specific products and accepting substitutes that meet a standard and prescribing the mean and methods of installation.

Advantages and disadvantages of rectangular duct section vs spiral duct section?

Spiral only comes in circular sections, so if floor-to-floor height is tight, and you'd like to make a higher dropped ceiling, you'll want to use rectangular duct so you can make a thinner profile in the duct height and a longer one in the duct length for the same cross-sectional area. For instance, an 18″ spiral round duct can carry the same amount of air (because it has the same cross-sectional area) as a 41×11 rectangular duct. . . so the spiral round duct will require 18″ of clear height above the dropped ceiling, and the rectangular duct, by comparison requires only 11 inches. Spiral duct is a bit less expensive (less sheet metal and happens to come. in longer lengths, so less in-the-field joining. Spiral duct is easier to seal tighter, offers less friction to the air for more efficiency and therefore a quieter fan because the fan doesn't have to work as hard. Rectangular duct, however, has a "drum effect" as the flat sides move back and forth like a drum absorbing sound energy, so rectangular duct, though increasing fan noise, attenuates much more of the fan's sound, per linear foot of ductwork, making for (possibly) a quieter result with long duct lengths. Branch take-offs, where a smaller duct branches off a larger trunk line, are (slightly) more difficult to construct in circular ducts than in rectangular ducts because of the simpler side wall geometry of rectangular ducts.

What are stepped or sloped footings for? See here so you know what they look like.

Stepped and sloped footings address the risk of punching shear. What is punching shear? The weight of a too-high concentrated load from the column wants to "punch through" the footing. See here for an example. The stepped or sloped footings gradually spread the load out over a greater area of the footing.

Name the lock type: The door is unlocked by a key outside; the outside lever is inoperative; the inside lever automatically retracts the latchbolt for egress.

Storeroom Lock

What does a "collector" in seismic design look like?

The floors and roof of a building form diaphragms, horizontal-resistance membranes important in seismic design that transfer lateral earthquake forces. Collectors (also called drag struts or ties) "drag" diaphragm shear forces from diaphragms to vertical resisting elements. In practice the collectors themselves look like sheet metal brackets or pneumatic shock absorbers that attach the floor of one part of a building to the wall of another. ***These are also called "drag struts" or "drag trusses" (remember that)

What is a "collector" in seismic design?

The floors and roof of a building form diaphragms, horizontal-resistance membranes important in seismic design that transfer lateral earthquake forces. Collectors (also called drag struts or ties) "drag" diaphragm shear forces from diaphragms to vertical resisting elements. In practice the collectors themselves look like sheet metal brackets or pneumatic shock absorbers that attach the floor of one part of a building to the wall of another. The component parts of irregularly-shaped buildings (i.e. both wings of an L-shaped building) sway in an earthquake out of phase with one another. Detailing each building part as its own structure, and connecting the parts with ductile metal, employs a "bend but don't break" strategy, making the joint between the parts less brittle.

How do we provide the capillary break (above ground) and hydrostatic pressure relief (below ground) for: Roof? Above-ground wall? Foundation wall? Foundation slab?

The idea behind a capillary break or hydrostatic pressure relief is that we redirect most of the rainwater or groundwater that would have otherwise made contact with the water control layer in the assembly-before the water even gets to that layer. This way, the water control layer has less water to control. Roof: No true capillary break will be provided for a roof because we couldn't really provide a proper capillary break, even if we tried. If we included a mechanically redirecting layer above the waterproof layer on a roof, and some water got past that first mechanical deflection layer, gravity would pull it toward the waterproof layer anyway. So in a roof, the top layer is usually the rain control layer and there's no room for error. Unlike the above-ground wall, the foundation wall, or the foundation slab, we expect water to get in after 20 or 30 years as the exterior waterproof layer (shingles or membrane) degrades by freeze-thaw and sunlight UV. We actually plan for a new roof every few decades. . . can you imagine if we needed to do the same for the walls or foundation?. In low-sloped roofs, the slope and drains remove the water to gutters, rain gardens, cisterns, or municipal drains. In sloped roofs, lapped shingles mechanically direct rain to a gutter and any rainwater that gets through the shingles may meet an optional peel-and-stick backup membrane. Or it may meet an attic ventilated to gradually dry out the moisture from tiny leaks. In the image below you can see the peel-and-stick rain control layer waterproof membrane before shingles were added above it. (I suppose you could call the space between the shingles and membrane a capillary break, but not really because gravity pulls water that gets past the shingles to the membrane anyway). In this image, you can also see the wall's fluid-applied waterproof layer. Portions of it will be covered by masonry, portions by metal panel rain screen, and portions (already installed) by precast concrete. Note that the roof membrane laps the wall's fluid-applied water control layer so that any roof water not directed to the gutters, can't sneak behind the wall rain control layer. Above-ground wall: We'll use an air gap capillary break, with a network of weeps and flashing to direct water from the air gap to the weeps. When rainwater sneaks past the mechanically deflecting layer (in the image above, the mechanically deflecting layer will be the (installed) precast concrete, the (not-yet-installed) stone, and the (not-yet-installed) metal panels). We need to think of keeping a wall dry as a system (rather than a product). See the capillary break air gap and the flashing that redirects water in the diagram below. Not all (and maybe not most) walls include a capillary break. For instance, the siding on a house typically sits flush to the rain control layer behind it; but buildings scientists tell us that the assembly will perform better with furring strips and a capillary break (see here for an excellent video). Most non-residential buildings will include a capillary break. Nor are all effective rainwater control layers watertight! They simply need to be able to shed rain that sneaks behind the mechanically-deflecting layer, so lapped building felt (tar paper) or lapped polymeric building wrap (Tyvek) can also work well as an air-permeable (tar paper) and vapor-permeable (both tar paper and Tyvek) rain control layer. In the lapped (but not taped) example, you'll then need to provide an air control layer at some other plane in the assembly. Foundation wall: We'll want to damp-proof (lower bar) or waterproof (higher bar) the foundation wall with fluid-applied goo or peel-and-stick membrane. But we'd prefer that our water control layer benefit from some system to reduce the water pressing against it. The ground is always wet. After a rain, hydrostatic pressure will push that excess subsurface water against a foundation wall if we don't send it elsewhere. Provide the capillary break hydrostatic pressure relief by redirecting water that would have otherwise pushed against the foundation wall down with dimpled drainage board (geotextile held slightly off a plastic sheet to keep soil out and allow water in) to a foundation perforated pipe "French drain." In times of excess subsurface water, the perforated pipe partially fills and water is directed down to daylight (for a sloped site) or to a sump pump (for a flat site). In the image below you can see the waterproof peel-and-stick membrane. Then we apply the dimpled drainage mat The drainage board directs water to a perforated pipe French drain that fills with water when excess is present. And then the water in the French drain perforated pipe is directed to daylight or a sump pump Foundation slab: Again, we'd like to protect the enclosure, just outboard of the enclosure, with a waterproof layer, so we'll install a plastic sheet (polyethylene, yellow in this case) right below the slab before pouring it like this. But we'd prefer to relieve the hydrostatic pressure of saturated soil pushing water against that sub-slab plastic layer. . . so below the plastic (and optional insulation) we'll find gravel pieces of similar size ("well sorted" or "poorly graded"). Subsurface water can then partially fill the reservoir made by the gaps between the 3+ inches deep gravel layer and keep the hydrostatic pressure off the plastic and out of our basement floor. Unlike the roof, above-ground walls, and subsurface foundation walls, we don't typically drain the water underneath a slab and rely instead on this "reservoir" system.

Reinforcement for masonry block in seismic zones

There are two types of masonry block walls with different sets of rules in seismic zones: those that are part of the seismic force-resisting system (load bearing, shear walls) and those not part of that system (partitions, non-load-bearing). Seismic force-resisting system: The level of reinforcement depends on the seismic design category, which in turn, depends on the risk and is determined by map (see here for the map. . . who knew that coastal South Carolina was so at-risk for a major earthquake?!). Walls should be structurally tied together at corners to add stiffness to the building to better resist lateral forces. Reinforcement requirements are very specific to level of risk, and not worth memorizing, but generally fall under the concept. . . . Low seismic risk: reinforcement extending the full height of the wall, through the foundation to the top of the wall every ten feet vertically and at jambs, reinforcement extending the full width of the wall every ten feet horizontally, and local reinforcement at lintels. Reinforcement around the wall's perimeter. See this elevation. High seismic risk: reinforcement extending the full height of the wall, through the foundation to the top of the wall every four feet vertically and at jambs, reinforcement extending the full width of the wall every four feet horizontally, and at lintels. Reinforcement around the wall's perimeter. See this elevation. Why all the reinforcement? We're trying to prevent this from happening (in the third image, the damage to the wall is in the lower-right corner). What does "reinforcement" mean in the context of block walls? See here for low seismic risk. In high seismic risk, you'll need bond beams for horizontal reinforcement. See here. Block walls not part of the seismic-force-resisting system (non-load-bearing partitions): for these random partitions, instead of tying walls together at corners structurally, we want to isolate masonry walls at corners (the opposite of the requirement for load-bearing walls) so swaying in the adjacent wall doesn't topple our wall where the two walls meet.

RMC vs IMC vs EMT vs GRC conduit

These are classifications of conduit wall thickness. Rigid metallic conduit (RMC): Thicker. Normally threaded. Intermediate Metal Conduit (IMC): Medium thickness. Also threaded. Electric metallic tube conduit (EMT): Thinner, and sometimes called, "thin wall" in the field. Too thin to be threaded. Used for smaller (branch) circuits and not designed for robust connections to the conduit upstream and downstream. Less expensive. Galvanized rigid conduit (GRC): Galvanized for corrosion resistance and thick enough to be threaded.

What are these black rings on the pipes for?

These pipe vibration isolators protect the downstream piping from most of the vibrational energy that would have otherwise been imparted to the building-wide chilled water piping system. They also help provide flexibility in pipe alignment tolerances in case the piping installers didn't coordinate perfectly with the contractors who installed the equipment that will be tied to the piping.

A large chandelier will be supported by a beam but can't be attached below the neutral axis. The beam is made of ______.

Timber. . . wood (heavy timber, dimensional lumber, or CLT) In a beam, the top sliver-above the neutral axis-is the part that sits in compression and the bottom sliver-below the neutral axis-remains in tension. In some point load cases, screwing into the bottom of the beam risks splitting the bottom of the beam.

Where to each of these go: Transformer Main distribution panel Electrical meters

Transformer: Steps the voltage down to a safer level before it enters the building. They sit on the utility pole, in the ground near the properly line, or inside the building in a basement or utility room. Main distribution panel: Divides the electricity into subsidiary circuits after the power enters the building. . . It says to the electrons, "You go to the restaurant commercial kitchen on the first floor and power the dishwasher; an you over there go to the apartment on the third floor and power four electrical receptacles and three light fixtures." It houses the circuit breakers (fuses) that switch off if there's overcurrent (dangerous short-circuit). It typically sits in a utility room or basement and can be small like this residential main distribution panel; or for larger buildings, it can be sizable like this. Electrical meters: These let the electric company know how much power you use so they can bill you. You've seen them before (they look like this) and can be outside the building on a wall or inside, housed in a basement or utility room. Generally, if we have multiple tenants, we'd prefer to meter them separately so each can pay the utility company directly. Folks tend to leave the A/C on when they know that the landlord pays the electrical bill. Older buildings often have one meter for all the tenants, and the landlord pays the bill. Newer buildings have the utility monitor each tenant with a separate meter. In retrofits, sub-meters can bee installed so that the landlord pays the bill for the whole building based on the utility's meter, and then collects electric from each tenant per the building's sub-meter.

Where is an outdoor transformer located when the power is buried underground? Where is the switchgear located for that same building?

Underground power lines are typically buried in a line 4' inboard from the street property line. Outdoor transformers for underground power lines are often on the property line that separates your building from your neighbor's building, 4' in from the street. Switchgear is located right at the point where the power enters the building, so inside the wall closest to the transformer.

How do you prevent graffiti?

Urethane anti-graffiti coatings prevent graffiti paint from adhering to the surface. Graffiti cannot bond to the surface well, and if it does bond, the coating can be easily removed, taking away the graffiti with it. How easy is it to remove graffiti from an anti-graffiti surface? Often it comes off with soap and water or a mild citrus cleaner! Urethane, which is kinda the same as Polyurethane, is also water-repellant. Same for most of the other anti-graffiti finishes. Likewise, rough surfaces like split-faced CMU or porous stone are tougher to scrub than smooth surfaces like glazed CMU or polished stone. Also. . . Plant thorny bushes under the tempting facades Remove graffiti as soon as it is discovered, as the tagger doesn't want to go through the trouble if it will be removed soon, robbing him of his desired notoriety Darker paint colors make graffiti stand out less, making it a less attractive surface Install motion-activated lights

Draw a vertical shaft wall detail in stick-built wall construction

Vertical shafts are required for ducts, pipes, conduits, etc. traveling from floor-to-floor; and for elevators and stairwells. Because if compromised they could easily spread fire and smoke from one floor to the floors above, they require a significant fire rating, necessitating construction of concrete, concrete block, or as many as five layers of especially-fire-resistant gypsum board in plan ("type X" gypsum board or "type C" gypsum board"). Penetrations, are minimized, and detailed to maintain the required fire rating (often 2, 3, or 4-hour rated). Mechanical shafts are often non-load-bearing. The plan detail is below. Because the fire protection must be maintained continually up the shaft, and builders may have difficulty screwing gypsum board to the inside face of the shaft wall when building from the room outside the cavity, we've developed techniques to affix fire-rated "gypsum liner" panels on the inside of the cavity wall from outside of the shaft.

In high wind areas with uplift risk-those in the path of hurricanes-codes require that wood-framed structures be structurally tied down, from roof to foundation. What hardware allows for this?

We can use tie-down straps, hurricane clips, or truss screws to hold down the roof structure to the wall structure We can use J-bolts, cable or rod tie-downs, or expansion bolts, to tie down the wall structure to the concrete foundation. Traditionally, we've sheathed wood-framed buildings with 8-feet tall OSB panels, but that requires two panels with a seam between. Taller (9-foot and 10-foot) OSB sheathing panels perform better than standard 8 feet tall panels because they allow continuous tension resistance by eliminating the need for a seam. To prevent roof sheathing uplift, attach the panels with glue or ring shank nails (which have spiral ridges that give the nail 40% more holding power).

When are parapet railings required on a roof?

When the roof includes-within 10 feet of a roof edge-mechanical equipment, hatches, or other equipment requiring regular servicing, code requires a 42-inch-high fall protection guard. Provided that the parapet extends up to that 42-inch height above the roof surface, the parapet itself can double as the fall protection. Many parapets that predate this 2010s-era safety requirement happen to fall just-short of the 42″ height minimum. Argh. Grandfathered roofs get a pass until a major renovation triggers an update to comply. The renovation typically means losing grandfathered status and adding a railing, either attached to the parapet mechanically, or if that's not possible for structural reasons, we've developed railing systems that do not penetrate the existing structure and use weighted bases instead. Typically the railings lean inward in section, away from the roof edge, both because that configuration is stronger, and because it's less visible from below. Some code officials will let slide, for example, a roof-mounted exhaust fan outlet within 10 feet of the perimeter, provided the exhaust equipment on the roof is only the exhaust grille (no moving parts that will need to be serviced). . . but if the motor up there may need maintenance one day, or if there's a filter that needs to be changed regularly, you'll need to provide the railing. For a new building, which solution is less expensive, parapet or railing? It depends: if the parapet was going to be 38 inches high ANYWAY, adding a few more inches may be a no-brainer. . . but otherwise, the railing system is less expensive by a lot. Of course, you MAY be able to get away with no fall protection if no equipment or walkways are near the edge (obviously you'll need to check the code): one more reason to not outsource locating roof-mounted mechanical equipment fully to the mechanical engineers.

Which one fails, the aluminum roof or the copper clips that attach it?

With galvanic action, one metal corrodes the other. The aluminum or zinc corrodes when in contact with brass or copper.

How do we reinforce storefront window frames?

With steel enclosed in the aluminum, when structurally necessary.

Where does roof flashing go?

You'll need flashing anywhere water, flowing downhill, meets an obstacle: Vent pipes, chimney, skylight, and roof valley. You'll also need step flashing anywhere water, flowing downhill, runs alongside an obstacle: chimney, a section of the building that extends beyond the roof, etc. see here.

Light loss factor (LLF)

ranges from 0 to 1, is the fraction of light that reaches the desk plane because of losses from dirt inside the fixture and from the lamp dimming over time through lamp "depreciation." So a room with a regular lamp wiping regimen and lamps that lose very little light over time will have a high LLF value and a dusty room with lamps that depreciate rapidly will have a lower LLF value.

Cavity wall masonry veneer with a concrete block backup wall: Use two-piece masonry ties or corrugated masonry ties?

two-piece masonry ties Corrugated masonry ties are only allowed with wood stud backup walls (residential construction), and only then with a 1″ airspace between the stud wall and brick veneer wythe. Most other configurations don't allow corrugated masonry ties because they fail over time Minimum cavity dimension of 1″ and maximum cavity dimension of 4.5″. Deeper airspace than 4.5 inches (for lots of insulation)? That's okay, but that triggers a performance code requirement (vs a prescriptive code at less than 4.5″): your structural engineer will have to prove that the ties you're using are structurally up to the task for your specific weight of masonry veneer, seismic profile, etc. Watch this excellent video on the subject (a must). Then scroll through this excellent blog post on the subject (also a must). So many clever ways to attach brick or stone to the block, steel, concrete, or. wood backup wall! Don't memorize them, but be familiar with them and know the extreme limits of corrugated sheet metal.

Coefficient of utilization (CU)

which ranges from 0 to 1, is the fraction of light that reaches the desk plane because of losses as the light reflects off surfaces. So a black room with lots of surfaces will have a lower CU value and a space with minimal white surfaces will measure a higher CU value.