Ch. 11 Roofs

Question 1

Low slope roofs

Answer 1

Have a slope up to 3/12

*Each 12 units of horizontal dimension, roof slopes upwards 3 units

Question 2

Medium to High Slope

Answer 2

Have a slope of 4/12 to 12/12
A slope of 12/12 equates to a 45 degree angle

*Some mansions and churches have a slope of 18/12, too steep to work from

Question 3

Gable Roof

Answer 3

Common roof style consisting of two inclined surfaces meeting at the highest side to form a ‘ridge” (Little House on the Prairie)

Question 4

Hip Roof

Answer 4

Sloped in four directions w/a degree slope similar to Gabled roof (stand alone garage or normal house roof)

Question 5

Gambrel Roof

Answer 5

Slope in two directions w/a break in the slope on each side (Barn like roof)

Question 6

Mansard Roof

Answer 6

Break in the slope of the roof on all four sides. A mansard roof constructed w/a flat deck is sometimes known as a modern mansard or deck roof.

Question 7

Butterfly Roof

Answer 7

Slopes in two directions - basically two shed roofs meeting at their lowest eaves

Question 8

Monitor Roof

Answer 8

Designed to provide light and ventilation; once common in factories; openable windows on the vertical sides are known as “clerestories”

Question 9

Sawtooth Roof

Answer 9

Commonly used on industrial buildings for light and ventilation; glass sections should face North for best amount of light

*Modern ventilation and lighting systems have eliminated the need for monitor and sawtooth roofs

Question 10

The most common roof types …

Answer 10

… constructed w/conventional framing:

• Shed
• Gable
• Hip
• Gambrel
• Mansard

Question 11

Common Truss

Answer 11

Arranged w/all the chords and diagonal members in the same plane

Question 12

Flink and Pratt trusses

Answer 12

Most common types used for pitched roofs

Question 13

Materials used in Arches

Answer 13

• Masonry
• Laminated Wood
• Steel

Question 14

Roof Deck Materials

Answer 14

• Plywood
• Wood Plank
• Corrugated Steel
• Precast Gympsum or Concrete Planks
• Poured Gympsum
• Poured Concrete
• Cement Planks containing Wood Fiber

Question 15

Roofing Materials must resist …

Answer 15

• Punctures from hail
• Corrosion from fog, salt air, smoke, and other pollutants
• Expansion and contraction from rooftop temps that can range from over 100 degrees in summer and below 0 degrees in winter

Question 16

Vapor barriers …

Answer 16

… are designed to reduce the diffusion of interior moisture into the insulation layer; consist of continuous sheet of material including:

• Plastic
• Aluminum foil
• Kraft paper laminated w/asphalt
• Asphalt saturated roofing felt

Question 17

Fluid Applied Membranes

Answer 17

Useful w/curved roofs; applied as a liquid and allowed to cure using:

• Neoprene
• Silicone
• Polyurethane
• Butyl rubber

Question 18

Shingles

Answer 18

Thin, tapered slabs of wood that are sawn from pieces of a tree trunk

Question 19

Shakes

Answer 19

Manually or machine split from wood and thicker then shingles. Usually from red cedar, white cedar, or redwood

Question 20

Class A Roof Covering

Answer 20

Effective against a severe fire exposure

Question 21

Class B Roof Covering

Answer 21

Effective against a moderate fire exposure

Question 22

Class C Roof Covering

Answer 22

Effective against light fire exposure

Question 23

Vegetative Roofs

Answer 23

Also known as Green Roof can vary from 20 lbs per square foot to 150 lbs per square foot