Quiz#10 Wood

The tensile strength of wood parallel to grains is ________than tensile strength of wood perpendicular to grains. Fill this blank with one of the options given below: A. Smaller B. Greater C. Equal D. All of the above is possible

B. Greater

Why wood is a popular construction material in the US? A. Renewable B. Biodegradable C. Inexpensive to produce D. Nontoxic E. All of the above

E. All of the above

Faster a tree grows will result in thinner annular rings and stronger wood. True False

False

Which of the following range of values is modulus of elasticity of wood? A. 1 - 2 x 106 psi B. 11 - 12 x 106 psi C. 21 - 22 x 106 psi D. 31 - 32 x 106 psi

A. 1 - 2 x 106 psi

The actual size of a 2" x 10" dimensional lumber is: A. 1-1/2" x 9-1/4" B. 1-1/2" x 9-3/4" C. 2" x 10" D. 1-1/2" x 9-1/2"

A. 1-1/2" x 9-1/4"

A floor frame system requires for a multi-family structure requires 400 - 2" x 10" x 14' joists. How many MBF of joists must be ordered? A. 9.33 MBF B. 93 MBF C. 11.20 MBF D. 112 MBF

A. 9.33 MBF

Wood shrinks the most in which direction? A. tangential B. radial C. length wise D. none of the above

A. tangential

How many board feet (BF) are there in a floor system built from 80 - 2" x 10" x 16' long joists (#2 or Better Southern Yellow Pine)? A. 1280 BF B. 2133 BF C. 2560 BF D. 2847 BF

B. 2133 BF

The grade stamp below designates that the wood was surfaced A. Ultra Dry (lumber <=19% moisture content) B. Green (lumber >=19% moisture content) C. Kiln Dry (lumber <=15% moisture content) D. Air Dry (lumber <=13% moisture content)

B. Green (lumber >=19% moisture content)

Crooking is a type of wood defect in which: A. Wood has lengthwise curvature from end to end B. Wood has lengthwise curvature from side to side C. Edges of wood roll up D. One corner of wood lifts up

B. Wood has lengthwise curvature from side to side

The microscopic living layer next to the inner bark which generates new cells and causes the growth of a tree is called: A. heartwood B. cambium C. outerbark D. sapwood E. pitch

B. cambium

One of the main differences between hardwoods and softwoods is that: A. hardwoods have wider annual rings B. hardwoods have a greater variety of cells C. hardwoods have resin ducts D. hardwoods are all diffuse porous woods

B. hardwoods have a greater variety of cells

Plain sawing logs yield the: A. least tangential shrinkage B. most lumber per log C. most pleasing grain for fine woodwork D. most dimensionally stable lumber

B. most lumber per log

Which sawing method can help control the shrinkage in wood? A. plain sawed B. quarter sawed C. tangential sawed D. longitudinal sawed

B. quarter sawed

A 12 inch deep pine beam is cut in such a way that the depth is in the tangential direction of annual rings. Compute the increase in depth as the moisture content changes from 10% to 30%. (The FSP of pine is 30% and it shrinks 8% in drying from FSP to oven dry in the tangential direction). A. 0.44 inch B. 0.54 inch C. 0.64 inch D. 0.74 inch

C. 0.64 inch

A floor frame system requires 56 -- 2" x 12" x 18' joists. How many thousand board feet (MBF) of joists must be ordered? A. 24.8 MBF B. 8.4 MBF C. 2.0 MBF D. 1.3 MBF

C. 2.0 MBF

How many board feet (BF) are in a 2" x 12" x 16' long hip rafter? A. 16 B. 24 C. 32 D. 48

C. 32

What species of wood is designated on this grade stamp? A. Southern Yellow Pine (SYP) B. Spruce-Pine-Fir (SPF) C. Douglas Fir or Larch (DF-L) D. Hemlock (HEM)

C. Douglas Fir or Larch (DF-L)

What is Glulam? A. Thin sheets of wood veneer bonded together with adhesive B. Strands of wood arranged in layers and bonded together with adhesive C. Number of layers of dimensioned lumber bonded together with adhesive D. None of the above

C. Number of layers of dimensioned lumber bonded together with adhesive

What is the type of force which wooden building frame will encounter during earthquake? A. Tensile force B. Compressive force C. Shear force D. Flexural force

C. Shear force

Which of the following is one of the most destructive insects that attack wood? A. Fungi B. Beetles C. Termites D. Marine-borer

C. Termites

Following is NOT an example of engineered lumber: A. Plywood B. Oriented Strand Board C. Timber wood D. Glulam E. Cross Laminated Timber

C. Timber wood

The moisture content in wood can: A. never be changed B. never effect its properties C. affect the strength properties of wood D. only increases to 30%

C. affect the strength properties of wood

How do you define wane (one of the wood defects) in wood? A. wood separations between annual rings B. lengthwise separations caused by mishandling or seasoning C. bark or other soft wood left on the edge of the board D. branch base that degrades mechanical properties

C. bark or other soft wood left on the edge of the board

Which of the following shapes can be classified as Heavy Timber? A. 2x4 B. 2x6 C. 4x4 D. 6x6

D. 6x6

Which of the following are typical uses for softwoods such as fir or pine? A. Window and door frames B. Piles and posts C. House framing D. All of the above

D. All of the above

Why do you think it is important to dry wood before using as a construction materials? A. Makes wood stronger B. Will reduce problems such as warping in future C. Makes wood lighter D. All of the above

D. All of the above

The term that refers to the fact that materials like wood have different properties in different directions is known as: A. martensitic B. exogenous C. hydration D. anisotropic

D. anisotropic

The major component in wood is: A. lignin B. resin C. extractives D. cellulose

D. cellulose

The material that is a natural adhesive and holds the wood cells together thus supporting the tree is known as: A. epoxy B. resin C. glucose D. lignin

D. lignin

Builders and engineers protect building frames from sideways or lateral forces by nailing plywood or stiff boards to walls True False

True

Building codes require that wood should not have more than 19% moisture. True False

True

Engineered lumber beams are available in much longer lengths without defects as compared to tree sawn beams. True False

True

Fresh cut lumber has over 30% of moisture in it. True False

True

Wood is a hygroscopic material. True False

True