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Serving Alberta's Roofing Industry Since 1961
SS Section 2: Asphalt Shingle Roofing
Asphalt shingle application directly over rigid
insulation is not permitted.
Asphalt shingle application directly over
dimensional lumber is not permitted.
Asphalt shingles must be applied to wood
sheathing over a ventilated air space.
For new construction, the roof decking shall be
minimum 11.1mm (7/16”) thick O.S.B. or minimum 12.7mm (1/2”) thick
When reroofing, plywood or O.S.B. roof sheathing
shall be minimum 9.5mm (3/8”) thick.
An upper asphalt shingled roof area shall
not drain directly on a lower asphalt shingled roof area. Drainage
shall be diverted using downspouts, diverters and/or gutters.
The roof framing and decking shall be designed
of sufficient strength so that they will support the anticipated
load such as construction loads. Roof decks shall be free of
damaged, deteriorated or decayed wood.
The surface of all roof decks to which a roofing
system is to be applied shall be sufficiently clean and dry so that
proper attachment can take place.
Roofing over existing asphalt shingles is not
permitted, tear off old materials to expose the decking.
Repair damaged or deteriorated decking and fill
abandoned deck openings with similar materials prior to
The minimum roof slope permitted for issuance of
an asphalt shingle roofing Warranty Certificate is 4:12
Use a membrane roofing system for roof slopes
less than 4:12 (1:3).
SS-2.2 Roofing Materials
The roofing materials shall conform to
the National Building Code — Alberta Edition and shall comply with
their applicable materials standard.
Materials shall be adequately labeled so that
proper identification of the materials may be made.
SS-2.2.2 Protection and Storage
All roofing materials that can be adversely
affected by moisture shall be protected prior to application and
only dry materials shall be applied.
Rolls of felt are to be stored on end, covered
and out of danger of water penetration.
SS-2.2.3 Application Limitations
No roofing material is to be applied when the
weather or the condition of its substrate is such that the required
installation procedures could not be followed or which would
jeopardize the performance of the roofing system or the safety of
SS-2.2.4 Asphalt Shingles
Inorganic asphalt shingles shall conform
to CSA A123.5-16, "Asphalt Shingles made from glass felt and
surfaced with mineral granules". Shingles may be three-tab or
SS-2.2.5 Organic Felt
The organic felt used for the
underlayment and eave protection shall be No.15 asphalt saturated
non-perforated felt conforming to CSA A 123.3-05 (R2015), "Asphalt
Saturated Organic Roofing Felt".
Nails used for roofing shall be
corrosion-resistant roofing or shingle nails conforming to ASTM
F1667-18(a) "Driven Fasteners: Nails, Spikes and Staples"
Nails shall have sufficient length to penetrate
through the asphalt shingle roofing and roof sheathing or have a
minimum penetration of 25mm (1") into the roof decking.
Nails shall have a head diameter of not less
than 9.5mm (3/8") and a shank thickness of not less than
The use of staples for the attachment of asphalt
shingles is not permitted.
SS-2.3 Flashing at Intersections
Sheet metal flashing shall consist of
not less than:
15 kg/m² (3 P.S.F.) thick sheet lead,
0.41mm (30 ga.) thick Z275 galvanized steel,
0.56mm (16 oz.) thick copper,
0.60mm (22 ga.) thick aluminum
or approved alternates.
SS-2.3.2 Valley Flashing
Open, woven or closed cut valleys are
permitted for W.C. issuance. California style valleys are not
Open valleys must be employed for
laminated asphalt shingle applications.
Where sloping surfaces of shingle roofs
intersect to form a valley, the valley shall be flashed with a
minimum of one (1) ply of 914mm (36”) wide self adhering modified
bituminous membrane centered in valley.
Open valleys shall be flashed with an additional
layer of sheet metal not less than 600 mm (2 ft.) wide. Where
adjoining roof areas differ in pitch, the metal valley flashing
shall contain a 25 mm (1”) high centre crimp.
The shingle underlayment shall be carried over
(on top of) the edges of the sheet metal valley flashing and be
trimmed to a line parallel to the interior cut edge of the
shingle’s triangular clip. Shingles and shingle segments on both
sides of valleys shall have their top valley edge clipped to form
an approximately 50mm (2”) wide triangle to direct runoff towards
the valley’s centerline.
For woven and closed cut valleys, shingles shall
be tightly pressed into the valley and fastened no closer than
150mm (6") from the valley centre line. Shingle terminations on
opposite sides of the valley shall be fastened with a minimum of
two (2) roofing nails placed vertically above one another.
For closed cut valleys, trim the overlapping
shingles at a minimum distance of 50mm (2") up/back from the valley
SS-2.3.3 Intersection of Shingle Roofs
The intersection of shingle roofs and
walls or chimneys shall be protected with flashing in accordance
with the National Building Code — Alberta Edition.
Sheet metal step flashing shall be installed
when the rake of a roof abuts a vertical wall or projection.
SS-2.3.4 Chimney Saddles
For sloping roofs, chimney saddles shall
be installed where the upslope side of a chimney is more than 750mm
(29.5") wide. See the National Building Code — Alberta Edition for
For chimneys less than 750mm (29.5")
wide, a chimney saddle need not be installed if the intersection
between the chimney and roof decking is protected by one (1) ply of
self-adhering modified bituminous membrane covered by a sheet metal
flashing (back pan) that extends up the chimney to a height equal
to not less than one sixth the width of the chimney, but no less
than 150mm (6") in height and shall extend up the roof slope to a
point equal in height to the top edge of the chimney flashing, but
not less than 1.5 times the shingle exposure.
Chimney saddles and valleys shall be treated in
accordance with Clause 2.3.2.
SS-2.4 Eave Protection and Metal
SS-2.4.1 Eave Protection
Eave protection shall extend from the roof edge
a minimum distance of 900mm (3 ft.) up the roof slope to a line not
less than 300mm (1 ft.) inside the inner face of the exterior
Eave protection is not required:
Over unheated garages, carports and porches,
Where the roof overhang exceeds 900mm (3 ft.) measured along
the roof slope from the edge of the roof to the inner face of the
On roofs with slopes of 8:12 (1:1.5) or greater.
Eave protection shall be laid beneath
the starter strip shall consist of one of the following:
No. 15 asphalt saturated felt conforming to CSA A123.3-05,
laid in two plies lapped 480mm (19") and cemented together with lap
Type M (mineral-surfaced roll roofing) or Type S
(smooth-surfaced roll roofing) conforming to CSA A123.2-03, laid
with not less than 100mm (4") head and end laps cemented together
with lap cement. This application is restricted to warm weather
applications to minimize the possibility of wrinkling,
Glass fibre or polyester fibre coated base sheets, or
Self-sealing composite membranes consisting of modified
bituminous coated material.
SS-2.4.3 Drip Edge Flashing
Pre-finished or galvanized sheet metal
drip edge flashing shall be installed along roof eaves and rakes.
The vertical flange shall be spaced a minimum distance of 6.4mm
(1/4”) from the fascia face. The deck flange shall extend a minimum
distance of 75mm (3”) on to the roof decking and shall be nailed at
maximum 400mm (16”) centres prior to shingle application.
At the eaves, the sheet metal drip edge flashing
shall be fastened directly to the roof decking beneath the eave
At roof rake edges, the drip edge shall be
fastened to the roof decking over the underlayment and eave
Exposed flashing edges shall be hemmed.
The field of the decking shall be
completely covered with a minimum of;
Asphalt-saturated sheathing paper weighing not less than 0.195
No. 15 plain or perforated asphalt-saturated felt, or
Underlay shall be installed parallel to the
eaves with head and end lap of not less than 100mm (4").
The underlay shall overlap the eave protection a
minimum distance of 100mm (4”).
The top edge of each underlayment strip shall be
sufficiently fastened to hold the underlayment in place until the
shingles are applied.
Ensure the underlayment is lying flat prior to
Every roof space or attic above an
insulated ceiling shall be ventilated with openings to the exterior
to provide an unobstructed vent area of not less than 1/300 of the
insulated ceiling area. Vents may be roof type, eave type, soffit
type, gable-end type or any combination thereof, and shall be
uniformly distributed on opposite sides of the building. Roof vents
shall be equally distributed so that approximately 50 percent of
the required vent area is located near the lower part of the roof
and approximately 50 percent of the required vent area is near the
ridge. For exceptions see National Building Code — Alberta Edition,
Section 9.19.1, Venting.
Coverage shall be not less than two (2)
thicknesses of asphalt shingles over the entire field of the roof,
disregarding three tab shingle cutouts.
SS-2.7.2 Starter Strip
A starter strip shall be installed along the
lower edge of the roof so that it extends approximately 19.0mm
(3/4”) beyond the eaves and rakes of the roof and be fastened along
the bottom edge with nails spaced not more than 300mm (1 ft.) on
Starter strips shall be;
At least Type M (mineral-surfaced roll roofing) not less than
300 mm wide,
Shingles of the same weight and quality as those used as a
roof covering with tabs facing up the roof slope, or
Pre-manufactured starter strips installed with sealant at the
SS-2.7.3 Head Lap
Shingles shall have a head lap of not less than
Shingles shall be fastened with no fewer
than four (4) roofing nails per shingle, placed in the nailing zone
so that nails penetrate through both shingle courses and the roof
decking, with no exposed nails. Nails shall be driven flush with
the shingle surface.
For roof pitches greater than 12:12, asphalt
shingles shall be fastened with a minimum of six (6) roofing nails
Fasteners shall be located 25mm (1”) to 38mm
(1-1/2”) from the end of each shingle and the remaining fasteners
equally spaced between them.
For three tab shingles, roofing nails shall be
located not less than 12.7mm (1/2”) above the tops of the
Fastener quantities may be reduced for
trimmed shingles in proportion to the shingle segment’s width. No
fewer than two (2) roofing nails shall be used to secure trimmed
No nail head shall be left exposed to the
SS-2.7.5 Securing of Tabs
Shingles and shingle tabs shall be
secured by a self sealing adhesive strip or by additional
application of plastic cement when hand tabbing.
Follow shingle manufacturer's
application recommendations and allow one (1) season for shingles
to seal. Shingles shall be hand tabbed during cold weather
applications in accordance with manufacturers
The first course of shingles shall be hand
tabbed to the starter shingles along eave and rake edges.
Partial and trimmed shingles shall be hand
tabbed at terminations such as gable edges, rakes, valleys, vents,
SS-2.7.6 Hips and Ridges
Hip and ridge shingles must be applied so they
extend not less than 100mm (4”) on either side of the hip or ridge
centre line and shall be lapped not less than 150mm (6”). Shingle
laps shall face away from the prevailing wind direction.
Shingles must be fastened with nails located not
more than 25mm (1”) from the edge and 25mm (1”) above the butt of
the overlying shingle on both sides of the hip or ridge centre
SS-2.8 Accepted Asphalt Shingles
SS-2.8.1 Inorganic Asphalt
Three tab and architectural inorganic
asphalt shingles complying with C.S.A. A123.5-16, "Asphalt Shingles
Made from Glass Felt and Surfaced with Mineral Granules" and
successfully completing an ARCA Warranty Ltd. material evaluation
as accepted products.
Building Products of Canada (BP)
- Mystique 42
- Vanguard 42 IR
- IKO Cambridge
- IKO Dynasty added
Malarkey Roof Products
- Highlander CS Laminate
- Legacy SBS Laminate
- TruDefinition® Duration® Shingles with SureNail® Technology
- TruDefinition® Duration® Storm Shingles with Sure Nail®
- Oakridge® shingle added
© 2020 Alberta Roofing Contractors Association