Deck 24: Sizing Joists, Rafters, and Beams

Question 1

What does a symbol such as L/ D = 360 represent?

A) code allowable deflection
B) live load value
C) size and spacing of lumber
D) title

Answer 1

A

Question 2

With a cantilevered beam with a uniform load, the live loads of exterior balconies are approximately half the normal floor live load.

Answer 2

False

Question 3

Hem-fir lumber is kiln-dried to make it straight and dimensionally stable.

Answer 3

False

Question 4

The ____ at any point of a beam is the measure of the tendency of the beam to bend due to the force acting on the beam.

A) fiber bending stress
B) bending moment
C) bond
D) horizontal shear

Question 5

When sizing a wood beam, what should you do next after determining the reactions?

A) determine the bending moment
B) determine the weight supported by 1 linear foot of beam
C) determine the horizontal shear
D) determine the pier sizes

Question 6

What causes a beam to break and fall between its supporting posts?

A) compression
B) vertical shear
C) deflection
D) horizontal shear

Question 7

Wood grain is composed of fibers that can be visualized as grains of rice that are aligned in the same direction.

Question 8

When determining beams with complex loads, the _____ is the sum of the reactions from each end of the beam.

A) maximum bending moment
B) point load
C) compression
D) reaction

Question 9

Which of the following is described using a nominal size and a net size?

A) drywall
B) strong back
C) sawn lumber
D) purlin

Question 10

When determining the joist size of engineered lumber required to span 16'-0", what should you do next after identifying the loading condition?

A) use the spacing column to locate a distance that exceeds the span
B) determine the deflection limit
C) select the spacing
D) determine the live and dead loads

Question 11

The sum of the tributary widths is equal to a quarter of the total distance between the bearing points on each side of the beam being determined.

Question 12

What term refers to a ratio of the amount a member will deflect in proportion to the applied load?

A) horizontal shear
B) vertical shear
C) compression
D) modulus of elasticity

Question 13

Douglas fir is used for structural members because it has a high strength to- weight ratio and excellent dimensional stability.

Question 14

A ____ is the tendency of a force to cause rotation about a certain point.

A) shear
B) deflection
C) moment
D) reduction

Question 15

Deflection deals with the _____ of a beam.

A) weight
B) total area
C) stiffness
D) material composition