BUR-1.1 General
.1
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.
.2
The surface of roof decks must be sufficiently
clean, dry and sound to receive roofing materials, so proper
adhesion and attachment may take place.
.3
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.
.4
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
.1
Dimensioned lumber decks may be constructed from
sawn lumber, planks or ship lapped boards.
.2
The direct mopping of hot bitumen adhered BUR
membranes to dimensioned lumber decks is not permitted.
.3
For uninsulated and protected membrane design
BUR roofing systems, a mechanically fastened auxiliary leveling
surface must completely cover a dimensioned lumber deck.
.4
For conventional insulated BUR roofing systems,
the vapour retarder shall be mechanically fastened to the wood
decking.
BUR-1.2.2 Sheathing Decks
.1
Plywood and oriented strand board (O.S.B.)
sheathing shall be manufactured for exterior application.
.2
The direct mopping of asphalt adhered BUR
membranes to sheathing decks is not permitted.
BUR-1.3 Concrete Decks
.1
Cast-in-place and pre-cast concrete decks shall
have a smooth dry surface and shall be adequately cured prior to
BUR application.
.2
Pre-cast concrete deck grout keys shall be grout
filled.
.3
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.
.4
Above deck projections such as anchor bolts and
plates shall be feather grouted to provide a smooth roofing
substrate.
.5
Hot bitumen may be used to adhere BUR membranes
directly to concrete decks.
BUR-1.4 Steel Decks
.1
Steel deck flutes shall be reasonably free of
snow, ice and debris, prior to BUR application.
.2
Unsupported deck openings are restricted to a
maximum dimension of 200mm (8").
BUR-1.5 Stramit Decks
.1
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.
.2
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
.1
Water based cementitious insulating fills
comprised of mixtures of cement/gypsum and insulation/vermiculite
are not accepted decks for Warranty Certificate issuance.
.2
Bituminous deck fills comprised of bitumen and
vermiculite are accepted for Warranty Certificate issuance.
.3
The finished surface of bituminous deck fills
shall be smooth and uniform.