Chapter 21 cladding with metal and glass (pt.2)
methods of assembly
-Metal and glass curtain wall systems can be classified according to their method of assembly -Options include stick systems, unit systems, panel systems, column-cover-and-spandrel systems -Curtain walls can also be designed as an outside-glazed curtain wall system or an inside-glazed curtain wall system -These various systems will be explored on the following slides...
unit systems
-Preassembled framed units with glazing -Takes full advantage of factory assembly -Pro - minimizes on-site labor -Cons - units need more space for shipping and more protection from damage when compared to stick systems
panel systems
-Made up of homogenous units that are formed from metal sheet -May or may not be glazed at the factory -Advantages and disadvantages are similar to the unit system -Production involves higher tooling costs of a custom made die or mold, which makes it advantageous only for buildings that requires a large number of identical panels
outside glazed curtain wall systems
-The glass must be installed or replaced by installers working from scaffolding or staging on the outside of the building -Outside glazing systems utilize simple, less expensive shapes -Usually reserved for buildings up to three stories in height
sloped glazing systems
-Many buildings feature glass roofs over areas such as lobbies, pools, courtyards, etc. -Glass roofs present special problems with respect to potential water leaks -Sloped glazing systems are well designed with a system of glazing gaskets -However, if a water leak occurs, an internal drainage system is also provided in the metal frame to channel the water away -To protect the building occupants, the building code requires special glass for glazing systems sloped more than 15 degrees from vertical
double skin facades
-A wall system constructed of two separate glass cladding systems separated by an airspace -This system has long been popular in Europe but has only seen limited use in North America -Various configurations of glazing and the use of space between the two skins are possible, including one that allows access for service and maintenance personnel -The airspace between the two skins may be naturally ventilated or ventilated by mechanical means -Double-skin facades can reduce unwanted solar heat gain, increase daylighting potential, and create a quieter building interior -However, the airspace can account for 5 to 10 percent of the usable floor area of the building
stick systems
-All materials are assembled in place at the jobsite -Pros - have advantage of low shipping bulk and high degree of adjustability to unforeseen conditions -Con - assembled on site under highly variable site conditions -Storefronts are typically stick systems
inside glazed curtain wall systems
-Allows glass installation and replacement from inside the building -Inside glazing is more convenient, safer, and more economical for tall buildings -It requires a more elaborate set of extrusions
"off the self" systems
-An "off-the-shelf" curtain wall system is available as either an outside glazed system or an inside glazed system -Some systems allow glazing from both the inside of the building and the outside of the building
metal panel cladding (options include)
-Architectural sheet metal made of thin flexible sheets -Metal plate wall panels made of thicker, heavier sheet metal (usually 1/8" thick) -Composite metal wall panels made from sheet metal laminated to a plastic core -Insulated metal panels made from sheet metal panels laminated to a rigid insulating core
column-cover-and-spandrel-systems
-Emphasizes the structural module of the building rather than creating its own grid on the facade -Advantages and disadvantages are similar to the unit system -A custom design must be created for each project because there is no standard column or floor spacing for buildings -Special care required in detailing spandrel panel support to ensure that panels do not deflect when loads are applied to spandrel beams of the building frame
