BUR Section 1: Roof Decks
- The roof deck provides the structural support for the roofing system. Roof decks shall be designed in accordance with the Alberta Building Code to support design and construction loading.
- The surface of roof decks must be sufficiently clean, dry and sound to receive roofing materials, so proper adhesion and attachment may take place.
- Where electrical conduits, fittings, bolts and plates project above the deck surface, a smooth substrate plane shall be provided to receive roofing materials. Correction to the substrate plane in the proximity of the projections must be addressed on an individual project basis.
- Roof deck perimeters shall be structurally supported. Deck openings require additional structural framing to support and to prevent excess deflection of the surrounding decking.
BUR-1.2: Wood Decks
BUR-1.2.1: Dimensioned Lumber Decks
- Dimensioned lumber decks may be constructed from sawn lumber, planks or ship lapped boards.
- The direct mopping of hot bitumen adhered BUR membranes to dimensioned lumber decks is not permitted.
- For uninsulated and protected membrane design BUR roofing systems, a mechanically fastened auxiliary leveling surface must completely cover a dimensioned lumber deck.
- For conventional insulated BUR roofing systems, the vapour retarder shall be mechanically fastened to the wood decking.
BUR-1.2.2: Sheathing Decks
- Plywood and oriented strand board (O.S.B.) sheathing shall be manufactured for exterior application.
- The direct mopping of asphalt adhered BUR membranes to sheathing decks is not permitted.
BUR-1.3: Concrete Decks
- Cast-in-place and pre-cast concrete decks shall have a smooth dry surface and shall be adequately cured prior to BUR application.
- Pre-cast concrete deck grout keys shall be grout filled.
- The maximum differential height permitted without correction between pre-cast concrete deck members is 6.4mm (1/4″). Height differences greater than 6.4mm (1/4″) but no larger than 19.0mm (3/4″) shall be corrected using cementitious grout or fill feathered to a maximum slope of 1:50 (1/4″/ft). When height differences exceed 19.0mm (3/4″), a topping coat shall be applied to correct the deck surface.
- Above deck projections such as anchor bolts and plates shall be feather grouted to provide a smooth roofing substrate.
- Hot bitumen may be used to adhere BUR membranes directly to concrete decks.
BUR-1.4: Steel Decks
- Steel deck flutes shall be reasonably free of snow, ice and debris, prior to BUR application.
- Unsupported deck openings are restricted to a maximum dimension of 200mm (8″).
BUR-1.5: Stramit Decks
- Stramit is a structural and/or insulating panel manufactured from straw fibre in 50mm (2″) or 64mm (2 1/2″) thickness as roof deck and/or insulation.
- Prior to re-roofing over stramit decks, ARCA Administration must be notified of the existing structural condition of the stramit decking.
BUR-1.6: Deck Fills
- Water based cementitious insulating fills comprised of mixtures of cement/gypsum and insulation/vermiculite are not accepted decks for Warranty Certificate issuance.
- Bituminous deck fills comprised of bitumen and vermiculite are accepted for Warranty Certificate issuance.
- The finished surface of bituminous deck fills shall be smooth and uniform.