Chapter 8 Roofs Flashcards

1
Q

Dead load

A

The weight of the bldg itself and anything permanently attached

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Diagonal sheathing

A

45 degree angle
1 X 6
After 1930

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Jack rafter

A

Used in hips or valleys to span between ridge board or wall plates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

LW truss

A

2 x4 or smaller

ELW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Live Load

A

Any load other than a dead load
Transient and moving
People, snow, furniture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Roof slope/pitch

A

Rise/run

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Open sheathing or skip sheathing

A

1 x4 or 1x6 are spaced out

4 to6” gaps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Straight sheathing

A

90 degrees

1 X 6” boards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

8 Roof types

A
Gable
Gambrel
Arch
Bridge Truss
Flat
Hip
Monitor
Sawtooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Common size for gusset plates

A

18 gauge

3/8” bite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

At what temps will the glue on mitered finger joints of LW trusses separate?

A

350 to 400 F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where to look for clues on the rafter size?

A

Rear of building since it may not have soffits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Best indicator of LW truss?

A

2x4 exposed rafter tails

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How much less is burn time of LW trusses?

A

1/4th

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Spacing for trussed rafters

A

24”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Valley rafter

A

On a hip roof, where two roof lines join

17
Q

Gambrel roof design

A

The lower slope is steeper than the upper slope

18
Q

Hazards of a Gambrel roof

A

Storage, contents

Roof operations

19
Q

What differentiates a Sawtooth roof construction?

A

Use of 2x8 rafters, with wood or metal for bracing

20
Q

Shed roof

A

Flat roof with a pitch that exceeds 10 degrees

21
Q

7 types of flat roofs

A
Conventional
Wooden I joist
Open web
Metal gusset or glue
Panelized
Open web bar
Nonstructural LW concrete
22
Q

Most common flat roof?

A

Metal Gusset plate

23
Q

What type of blade do you use to get through a flat non structural concrete roof?

A

Rotary saw with a carbide tipped wood blade or multi use blade
Or chainsaw with a carbide blade, but it will fuck it up

Note: book says multi use in summary

24
Q

Main era for Bridge truss style roof?

A

Historical and Industrial

25
Q

Identify an Arched truss/rigid truss/Rib Arch

A

Bottom chord sits on wall

On a bowstring, the top chord sits on the wall

26
Q

Identify a Bowstring Truss

A

Top chord sits on wall
Vertical members are in compression
Diagonal members are in tension

27
Q

Wauldbaum’s center roof collapse was caused by:

A

Double rain roof
Concealed spaces in ceiling
Failure to recognize signs of weakening

28
Q

How long can Timber Truss Roofs last in a fire?

A

30 minutes or more

29
Q

4 factors that affect timber truss roof failure

A

Alterations
Mass
Location
Size

30
Q

Metal roofs save how much energy and are made of

A

20%

22g-26g