1. Roof Decks
1.1. Types of decks
1.1.1. Concrete
1.1.1.1. 28 Days to cure
1.1.2. steel
1.1.2.1. Overlay board must be aplied
1.1.3. Plywood
1.1.3.1. RCABC requirements: 16” O.C – 1⁄2” sheathing 24” O.C – 5/8” sheathing BC Building Code: 16” O.C – 1⁄4” sheathing 24” O.C - 3/8” sheathing
1.2. Deck repair
1.2.1. Wood deck repair
1.2.1.1. Small holes in wood decks can be repaired with sheet metal over the hole. Replace sheathing for larger holes in wood decks
1.2.2. Steel deck repair
1.2.2.1. Surface rust Primed and painted Significant rust should be cut out and replaced.
1.2.3. Concrete Deck repair
1.2.3.1. Concrete decks inspected for pitting, bumps, divots and manufactures limitations should be filled in or ground down.
2. A min. slope of 1/4" in 12 Recommended
3. Details
3.1. Penetrations & Deatils
3.1.1. 8" away from walls cants or eaves
3.1.2. vent flashing 1st ply 4" passed the flange 2nd ply 6" past
3.1.3. stack flashing center hole 1st ply min of 2" 2nd 1 "
3.2. Drain Details
3.2.1. min 2 lbs per sq ft required for drain
3.2.2. Lead sheets are to be primed, with both sides embedded in mastic & extending a minimum 6” past the drain flange and 1” into the bowl.
4. primers and mastic
4.1. Wet Patch cold applied asphalt can be applied in damp or wet environments Cut back A generic term for solvent-based primers and mastics Emulsion Water based mastic or adhesives
5. Surfacing
5.1. Types of aggregate used in Bur
5.1.1. 1/4" 3/4" pea Gravel
5.1.2. mineral surface (sbs cap sheet mopped)
5.1.3. smooth surface (reflective paints and emulsions
5.1.4. protected roof membrane (PRMA)
5.2. Max aggregate Slope: 3/12 BC code 2.5/12 Rcabc
5.3. Purposes
5.3.1. ballast (weight for insulation) Traffic protection Protection from U.V. Rays Fire protection
6. Cant strip
6.1. Typically made of wood or fibre
6.2. 3" at walls
6.3. 4" at eaves
6.4. Used to turn a 90 Degree to two 45 Degree bends
7. Vapour barriers
7.1. Vapour barriers are nailed or adhered & fully sealed. Minimum of 2 plies of No. 15 fully mopped felt. Vapour barriers protect moisture from in the building getting into the roof system. Vapour barriers are only required when specified by the design authority.
8. Coverboard
8.1. 2 layers required with heat sensitive insulations
8.2. Use joint tape on all seems of the first layer
8.3. No.15 perforated felt or fiberglass felt
8.4. 6" minumum centered on seam
9. Insulation
9.1. screws and plates
9.1.1. 8 field, 12 perimeter, 15 corner should be nailed back on slopes over 1/12
9.1.2. install wood nailers over 1/12 slope to prevent slippage 4 feet for horizontal application and 2 feet for vertical
9.2. 2 layers of cover board required, 6 inches on center minimum, and joint tape on all seams of the first layer (# 15 felt or fiberglass felt)
10. Bitumen
10.1. Coal tar pitch
10.1.1. Not really used anymore but may come across it if tearing off (extreame irritant that causes burning of skin and swelling of eyes)
10.1.2. requires dead flat to 1/4 inches in 12 inches
10.2. Cutbacks
10.2.1. solvent based bituman mastics, must be applied to dry substrates
10.3. Emulsions
10.3.1. typically a water based bituman mix that can be applied to damp surfaces
10.3.2. there is a possibility of it freezing so it should not be installed if freezing temps are expected for the next 48 hours
10.4. Asphalt
10.4.1. most commonly used in canada
11. Membranes
11.1. No.15 perforated Typically 36" wide Fiberglass or polyester facer
12. Asphalt
12.1. Asphalt Gravel Application Rate
12.1.1. Single pour - 60 lbs per sq (asphalt) 400 lbs sq (gravel) Double pour - first application 60 lbs per sq (asphalt) 400 Lbs Gravel per sq Double pour – second application 60 lbs per sq (asphalt) 400 lbs gravel per sq Modified double pour– first application 40 lbs per sq (asphalt) 200 lbs gravel per sq Modified double pour – second application 60 lbs per sq (asphalt) 400 lbs gravel per sq Alternate Modified double pour -40/ 60 lbs per sq (asphalt) 500 lbs gravel per sq
12.2. Temps.
12.2.1. Type 1 Slope up to 1/12 EVT 400 FBT 475 Flashpoint <525 Type 2 Slope Up to 1/12 EVT 425 FBT 500 Flashpoint<525 Type 3 Slope 1/12 to 3/12 EVT 425-450 FBT 525 Flashpoint<525 Type 4 slope 3/12 and up EVT 450-475 FBT 525 Flash point <525
12.3. Application Rate
12.3.1. Insulation 20 lbs per square No. 15 Perforated felt 20 lbs per square Fiberglass 25 lbs per square Polyester 35 lbs per square MS stripping 20 lbs per square Flood/Glaze Coat 20 lbs per square Pour coat for PRMA 60 lbs / square