I1 - Roofing Materials - LT# 2 Flashcards
What is the primary safety concern when working on roofs, and how is safety improved to reduce danger?
Falls when working at heights,
Use of fall protection
What is a proper slope for an extension ladder and how high must it project above the upper landing (roof?)
4:1 (V:H) and 36” projection above upper landing
On a surface below 10’, is fall protection required?
Only if the surface is jagged or rough.
Define the term Fall Protection:
Includes: Guardrails, personal fall protection, safety nets, control zone, safety monitor system which includes a control zone
Define the term Fall restraint:
Restricts travel using a harness or belt, with suitable & compatible components (D-Ring, Lifeline, and/or Lanyard, rope grab & anchor). A belt is allowed.
Define the term Fall Arrest:
Prevents a falling worker from hitting any objects & from hitting the ground at any level below the work area. Includes Full body harness. Limit free fall to 4’
How far above the eave should tools & equipment be stored?
2 Meters
How can eavestroughs be protected from ladder damage?
Blocking or ladder standoffs
What is the minimum joint offset between courses for wood shingles or shakes?
1.5”
What is the narrowest shingle allowed for roofing?
3”
What should be established on the ground for safety when stripping a roof for re-roofing?
A safety zone using barricades, or flagging & signage.
Who installs most roofing?
Most roofing is subcontracted by the Carpenter. Carpenter is then responsible for the safety & other aspects of the roofer’s work.
When might a carpenter do some roofing work?
Smaller job, like on a shed or addition.
For a long roof life, the condition of:
Roof sheathing, underlay and eave protection is vital.
What sort of ladder setup is needed to access a roof?
1) Use a single or extension ladder
2) Ladder projects 3” above the level of the landing
3) 4:1 RATIO (H:V)
What is the safest way to bring materials onto the roof?
Hoist, rope or lift them onto the roof
A fall protection system is used beyond which heights?
10 feet OR MORE
What sort of fall protection is needed for flat roofs and roofs no greater than 4:12
1) Guardrail
2) Personal fall protection system
3) Safety nets
4) Control zone
5) Safety monitor system with control zone
What sort of fall protection is acceptable for roofs with a slope ratio greater than 4:12 but less than 8:12
1) Guardrail
2) Personal fall protective system
3) Safety nets
Should a control zone & safety monitor be utilized in a roof steeper than 4:12?
No
What sort of fall protection is acceptable for roofs with a slope ratio greater than 8:12
1) Nailing toe boards in conjunction with a personal fall protection system or personnel safety nets
2) If working material is not fiqt for toe board (such as heavy materials) then workers should use roof ladders, or acceptable work platforms in conjunction with a personal fall protective system
What are guardrail requirements (1st on the list of preferences)
1) 1.0 to 1.1 above the work surface
2) Consist of a top rail, mid rail and toeboard
3) Resistant to 125 lb horizontal load
4) Supported by uprights, max spacing of 2.4 to 3.0 m
5) Use a min. of 2x4 top rail for upright spaced at 2.4 m OC
6) Use a minimum of 2x6 top rail for uprights spaced at 3.0 OC
7) Use a mid rail of 1x6
Define control zone:
The area between an unguarded edge of a building or structure and a line that is set back a specific distance.
What is the minimum width of a control zone?
2 m (6.5’), sloped no steeper than 4:12 (v:h), non slippery.
If a safety monitor is not used, a control zone must:
Be clearly marked with a raised line.
A safety monitor must:
1) Be experienced in the work overseen & trained in the role of safety monitor
2) Be present at all times when a worker is in the control zone
3) Have complete authority when it relates to falling
4) Engage in no other duty
5) Be located to have clear and constant view of the work
A safety monitor must monitor no more than:
8 workers
Lanyard must provide how many feet of free fall?
4 feet
What is a rope grab?
Connects the lanyard to the lifeline, these devices can be moved up and down the lifeline if pushed steadily.
When a shock absorber is used, a lanyard’s freefall can be increased to:
2 m.
Three types of lifelines:
Vertical, horizontal and retractable
What is a designed fixed support?
Load-rated anchor designed for fall protection, permanent part of structure
What is temporary fixed support?
Designed to be connected to the structure following specific installation instructions.
What is an existing structural feature support?
Not designed for anchor, but approved by engineer
What is the pendulum effect?
Further, you move from the anchor point, the greater chance of swinging during the fall, more swing means more force.
Before using any fall arrest system greater than 25’, the employer must establish:
Written rescue procedures
A worker dangling for more than ____ minutes will lose circulation in their legs, resulting in injury
4 minutes
A worker dangling for more than ____ minutes will lose circulation in their legs, resulting in injury
4 minutes
What is used for splitting and trimming shingles or shakes?
A roofer’s hatchet.
What are the purposes of underlay material?
Provides a second layer of protection from weather and it cushions soft or thin roofing materials from the heads of the sheathing fasteners.
Non-perforated asphalt-impregnated paper is used under
Asphalt shingles or tiles
Perforated paper is used between each course of
Cedar shakes
What does code ask for when overlapping underlay?
2”, but half lapping the sheets is a more solid practice
A drip edge is needed where on a roof?
At the eaves, roofing required to be with a small drip edge of at least 1/2”
How is an under-course installed (Asphalt shingle)
At the eave, consists of an upside-down layer of shingles fully covered by the first course of exposed shingles.
How do you cap hips and ridges?
Capped with single tabs of three tap shingles. Cut the shingles into three pieces at cutout.
How to install wood shingles?
Use a layer of wood shingles under the first course of wood shakes or shingles, the taper will kick the first course up to match the angle of the following courses
How to fasten cedar shingles?
Hot dipped galvanized box nails, two nails per shingle
Wood shingles should be spaced slightly apart, approx:
6 to 9 mm, space allow for expansion when they get wet
Sapwood on shingles tends to:
Rot much faster than heartwood. Lighter in color, less dense.
The hip and ridge capping of Cedar shingles is done:
Fitting individual shingles together, if making the caps, overlap the shingles left then right.
How is windblown snow prevented from entering an attic when using shakes?
A strip of perforated #15 felt underlay is placed between each course of shakes.
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