I-1 Roofing Materials Flashcards
true of false decks or open areas should be treated as roofs
TRUE
slope of roof and roofing materials
flat roofs 1.5:12 - 2:12
low slope 2:12 - 4:12
conventional-slope 4:12 - 9:12
steep slope roofs steeper then 9:12
torch on can be used on all
ashphault used on 4:12 and up
metal 3:12 and up
slate tile and concrete tile used on steep roofs 6:12 and up
Fire rating class A roofing material
the most fire resistant class and should be used in areas where wild fire is prone. includes fibreglass asphalt shingles, metal, clay and concrete roofing.
- treated shakes have fire rating A if installed over fire resistant material
Fire rating class B roofing materials
includes fire retardent treated wood shakes that are not installed over a fire-barrier material and some asphalt shingles
Fire rating class C roofing materials
the least fire resistant type of roofing material. includes some asphalt shingles that have organic fibre base, non treated wood shakes and shingles.
Asphalt shingles
one of the most common in north america due to low cost and long life expectancy. com ein many sizes and can be installed on low slope roofs with certian application or any other roof normally.
mae up of 1m (39”) with and exposure of 5.5”. each course is glued to the previous course with a factory-applied strip of asphalt adhesive
three-tab shingles
three tab square butt shingles were very common for years. lost popularity due to laminate shingles
Laminated shingles
most asphalt shingles are made with multiple lamination. these shingles give a rough appearance that look like cedar shingle roofs. also knows as architectural shingles.
use base mat material made of organic fiber glass. then covered with mineral or ceramic material to block UV
Square of asphalt materials will cover approximately 9.3m2of roof
Wood roof coverings
cedar is most popular
heartwood is used because its water resistant
sapwood should not be used for roofing
difference between cedar shakes and shingles
shingles are sawn on both surfaces while shakes are split on one or both surfaces.
cedar shingles
can be installed on slopes 3:12 and steeper. exposure length is based on the roof slope, shingle length and shingle grade
No. 1 Shingles
top grade shingles used for roofs and sidewalls. are 100% heartwood 100% clear and 1005 edge grain. identified by blue lable
No. 2 Shingles
these shingles meet BCBC. due to flat grain they warp and twist over time giving the roof an un level surface.
require no nots 250mm from bottom of 400mm long shingles. identified by red label
No 3. shingles
these are not aloud to be used as roofing materials. only for sidewall applications. black label
built-up and membrane roofing
commonly used for low slopes roofs and flat roofs. the minimum allowable slope is 1:50 (1/4”:12)
Built-up Roofing
known as “hot tar and gravel” consists of three layers of roofing felt, mopped with hot tar (bitumen), between layers and covered with layer of hot tar. in many cases a layer of pea gravel is spread out ontop to provide UV protection
Membrane roofing
comes in rolled sheets and is most common for flat roofing and low slope roofs (JCC HOUSES) it is rolled out with overlapping seams and fused together by heat. flexible and easy to use
three main types of membrane roofing
- thermoset: seams are chemically crosslinked and vulcanized
- thermoplastic (PVC sheet vinyl and other plastics): seams are bonded together with heat or solvents.
- modified bitumen (torch on or torch down): large flame throwing torch is used to melt the seams together and to adhere the product to the roof sheathing.
normally three layer felt, torch on, and cap layer
Roll roofing
inexpensive product that is normally used for sheds and temporary buildings. has short life span and forms wrinkles over time.
Metal roof coverings
coated steel roofs are lightweight and non flammable and resistant to moss buildup. disadvantages are scratching denting
Sheet metal roofing
finished are baked enamel or vinyl plastic. aluminum, copper, and stainless steel are available but not often used.
usually bend into shape to make stronger so they can span to supports.
exposed screw sheet metal roofs
use exposed screw with neoprene washers. creates finished product with hundreds of little holes
hidden fastener sheet metal
“standing seam” consists of flat sheets that are less then 2’ wide. overlapped and edges interlock (pro lock). fasteners are hidden
Metal shingles
made in many profiles an colours. manufactured in strips similar in size to three tab shingles. lightweight and last twice as long.
tile and slate
long lasting roofing material made from clay, concrete or slate. because they are heavy the roof must be built up to hold. BCBC required min slope of 6:12
Clay tiles
long lasting roofing material often specified for architectural reasons. often known as traditional overlapping barrel shape. formed with special nail holes at the top. leaks are hard to fid and hard to fix
Concrete tiles
finished these tiles usually made from baked enamel. usually barrel shaped and cut with diamond tipped saw.
Slate
natural stone that can be shaped into tile like flat sheets. drilled holes are made for nailing. with right fasteners can last 80-100 years
Green roofs
constructed with membrane-type roofing covered wit root barrier. then drainage layer mat of gravel and topped with soil then grass is planted
solar photovoltaic shingle roofing
act as both roofing and solar electricity producer. very thin and flexible and can be intergraded with asphalt shingles
roofing felt
most roofing felt types come in 36” rolls .
decay on wood shingles happens on the underside first. wood shakes require a perforated paper underlay. this breathing type of underlay gives shingle ability to dissipate moisture.
Eave protection
this can be the coldest part of roof during freezing weather. snow can remain frozen o exposed eave, snow over living space will melt and cause ice. ice dam at eve can cause water back up and leaks.
BCBC requires shingle, shake and tile roofing have eaves protection that extends 3 feet up the slope to a line not less the 1 foot beyond the inside faec of the exterior wall.
eave protection required when
- overheated garages, porches and carports
- when roofing overhang is more then 3’ along slope of interior wall
- roofs with slope greater then 8:14
- in regions with 3500 in fewer degree days
Flashing
roofing requires flashing at intersections and sometimes drop edge to protect lowest edge of roof. intersections include valleys, where roofs meet walls around skylights and chimneys
materials for flashing
usually made from metals that must be able to be bent and resist weather
Lead and copper flashing
both very flexible and resistant to weather. both very expensive. used when flashing must last indefinitely.
lead: very flexible and can be moulded by hand
copper: requires machine bending
aluminum flashing
not recommended, too light and easily eroded by salt air
steel flashing
most cost effective and will last long as most common roofing materials. usually galvanized or enamel coated.
flashing roof openings
when skylights are installed all four sides must be flashed. the downslope is the base flashing, sides are flashed with step flashing and top of opening is flashed with back pan.
Vally flashing
used when open valley is built. minimum width of valley flashing is 24”.centre of valley flashing is bent so water will run down it.
some shingles do not require valley flashing but underlay prep must be installed up valley vertically.
Roof vents
attic spaces must be ventilated to prevent moisture damage ad reduce heat build up during summer months. this is done by soffit vents.
roof vents are made from plastic or metal. screened to prevent insects.
plumbing vents
the buildings waste plumbing is required to be vented, and this stack pipe will normally pass through the roof. at least one vent is required at at least 3”
hidden gutters
inside hidden gutters are finished with torch on roofing membrane. butter must be large enough to catch water and be sloped towards drain.
scuppers
flat roofs often use scuppers instead of eaves troves. a curb wall is made and cant strip installed. openings in this wall will drain into a box connected to a downspout.
Sloped insulation package
flat roofs are not completely flat. must have slope of 1:50. to achieve this sometimes tapers are installed on roofing sheathing.
safety concerns of roofing
heights getting materials on roofs heat stroke falls through skylight rooftop vents exposing fumes torches
using ladders to access roof
- rest ladder on firm level base
- ladder must go 3” above surface
- do not stand on two top rungs
- 4 vert 1 horizontal slope
- do not exceed ladders weight rating
- do not climb ladder with material or tools
- three point contact with ladder
Working at heights
fall protection at 10’ or more.
acceptable fall protection of roofs no greater then 4:12
- guardrails
- personal fall protection
- safety nets
- controle zone
- safety monitor system
acceptable fall protection on roofs greater then 4:12
guard rails
personal fall protection
safety nets
Guardrails
- 40-44” above work surfaces
- top rail mid rail and toe board
- must resist 57kg of horizontal load
- ## supported by uprights 8-10’ apart
fall restraint system
allows workers to travel far enough to reach unprotected edges.
consists of harness and components (d ring, lifeline, lanyard, rope grab anchor).
anchor must be able to resist weight of 4x the weight of worker
controle zone
are between an ungraded edge of a building or structure and a line that is set back a specific distance. controle zone must be sloped no steeper then 4:12 and be non slippery. no workers permitted in this zone.
Safety monitor
a trained worker designated to monitor activities in a control zone. must be
- experienced in work overseen and trained
- be present at all times workers are in control zone
- engage in no other duties when active as safety monitor.
- must have clear continuous view of worker at all times.
lanyards
rope grab and lanyard should be rigged to allow maximum free fall of 4’.
- never tie knots in lanyard
- never store around chemicals or shark objects
- do not leave in direct sunlight for too long
- inspect lanyard before use
rope grabs
used to connect lanyard to lifeline. lock when pulled tightly. designed for specific life lines and must be attached in correct direction or will not engage. check all connecting devices for
- rust
- bends
- cracking
- deformation
- singes of wear
shock absorbing devices
reduce impact of lifeline stopping a fall. required if wire rope lanyard is used. when used freefall limit can be increased to 6.5’
three types of lifeline
vertical, horizontal and retractable
vertical life lines
- CSA approved
- withstand 6000 lbs of force
- made from synthetic wire rope
- no knots
- be secured to anchor that can hold 5000 lbs
- only one worker attached
- extend 4’ off the ground
horizontal lifelines
- provide minimum 800lbs of suport for worker
- have breaking strength of 20 000 lbs
- made from 1/2” diameter wire rope or larger
- be free of knots and splices
- be secure to anchor that can hold 16 000lbs
- have span of 20’ but less then 60’
retractable lifeline
lifeline that is spooled on a retracting device and attached to adequate anchor.
- located above worker
- unwinds at workers normal moments
- lock in quick movements
snaphook
connects lanyard to rope grab or harness. must be self locking mechanism
carabiner
designed to remain closed under twist loads. can be used instead of snap hook.
anchor system
three types
- designed fixed supports
- temporary fixed supports
- existing structural features
designed fixed support
load rated anchors specifically designed for fall protection purposes. permanently installed on integral parts of building or structure.
temporary fixed supports
designed to be connected to the structure following specific installation instructions.
existing structural features
not designed as anchor points but a pro engineer or competent person has verified as adequate for that purpose. concrete columns, steel components etc…
pendulem efect
keep anchor and lifeline perpendicular to worker to reduce swinging if fall.
bottoming out
occurs hen worker hits lower level, the ground or some other hazard before fall arrest works. this happens when the total distance allowed by system is greater then that of distance to obstacle or ground.
maintenance of fall arrest
- inspected by qualified person
- kept dry and away from substances
- maintained in good working order
Emergency rescue plan
employer must provide written rescue plans. worker must be briefed on this procedure along with anyone else on site.
