Ch 11 - Roofs

Question 1

Fundamental safety points

Answer 1

Roofs not as strong as floors because they are designed to support lighter live loads
Many roof types have concealed spaces between ceiling and the roof deck
Loads may be added to roofs for which they were not designed

Question 2

Rafter spacing

Answer 2

12 to 24 inches

Question 3

Truss spacing

Answer 3

2 to 4ft

Question 4

Flat roof coverings

Answer 4

On the roof decking:

Vapor barrier
Insulation
Membrane
Drainage layer
Wear course

Question 5

Class A roof coverings

Answer 5

Effective against severe fire exposure

Question 6

Class B roof coverings

Answer 6

Effective against moderate fire exposure

Question 7

Class C roof coverings

Answer 7

Effective against light fire exposure

Question 8

Photovoltaic roofs

Answer 8

Energy feed from PV cells cannot be isolated or shut off. All wiring and conduits must be assumed to be live

Question 9

Green (vegetative) roof

Answer 9

May add considerable load to roof
May be flammable