Roofing
Flat Roofing in Calgary
Axion Roofing installs and repairs low-slope roofs in Calgary: two-ply SBS torch-on, EPDM rubber, TPO membrane and tar-and-gravel replacement, with drainage and parapet flashing corrected.
Axion Roofing installs and repairs low-slope roof systems on Calgary homes, infills, garages, commercial bays and condo buildings. Flat roofs in Calgary fail at three places: the drain, the parapet and the transition to the wall. Axion Roofing rebuilds those three details on every low-slope job rather than re-coating over them.
The National Building Code, Alberta Edition treats a roof with a slope under 1 in 6 differently from a pitched roof. Section 9.19 doubles the required venting on those assemblies to an unobstructed vent area of at least 1/150 of the insulated ceiling area, compared with 1/300 on standard slopes. Calgary flat roofs that were built without that ratio trap moisture in the deck.
01 / 03
Comparing the four flat roofing systems Axion Roofing installs
- 01
Two-ply SBS torch-on
SBS modified bitumen carries a base sheet and a granulated cap sheet torched into a continuous membrane. SBS handles Calgary temperature swings better than single-ply because the polymer stays flexible below freezing, and it tolerates foot traffic from HVAC service. It is the default for residential infills and small commercial decks. - 02
EPDM rubber
EPDM is a single-ply synthetic rubber membrane installed in wide sheets with seam tape or adhesive. EPDM resists hail impact well because it deforms rather than fractures, and it takes ponding water better than most alternatives. Seams are the maintenance point. - 03
TPO
TPO is a heat-welded single-ply thermoplastic membrane with a reflective white surface. TPO welds produce a stronger seam than taped EPDM, and the reflective surface lowers summer deck temperature. Axion Roofing specifies TPO most often on commercial buildings with large uninterrupted spans. - 04
Tar-and-gravel replacement
Built-up tar-and-gravel roofs still cover many Calgary bungalow additions and older commercial buildings. Once the gravel migrates and the felts blister, Axion Roofing strips the assembly and replaces it with SBS or a single-ply membrane rather than patching.
Low-slope assemblies
Membrane, drainage and the parapet detail
01Base sheet and cover board over the low-slope deck, ahead of the cap sheet.
02Torch tools staged on the deck. Two-ply SBS goes down in sequence, not in one pass.
03Granulated SBS cap sheet run out beside bare plywood, showing the transition.
02 / 03
What Axion Roofing corrects on a Calgary flat roof
- Drainage. Standing water 48 hours after rainfall means the slope or the drain is wrong. Axion Roofing adds tapered insulation to build positive slope to the drain instead of accepting ponding.
- Parapet caps and counter-flashing. Wind-driven rain enters at the parapet before it enters anywhere else. Metal cap flashing and proper counter-flashing get rebuilt.
- Curb flashing at mechanical units. Every rooftop unit, vent and skylight curb gets flashed as a curb, not sealed as a joint.
- Deck condition. Wet or delaminated deck sheets get replaced before the membrane goes down.
From the jobsite
Low-slope sections on Calgary buildings
Where the membrane meets shingled slopes, stucco chimneys and parapet walls is where flat roofs fail.
Click any photo to enlarge
Low slope membrane deck beside new shingled roof 
Low slope section with black membrane beside stucco chimney 
Membrane deck and large shingled hip roof new build 
Granulated membrane installed over plywood low slope deck
03 / 03
Flat roof repair versus flat roof replacement
Repair a Calgary flat roof when the damage is a discrete puncture, a lifted seam, or a single failed curb on an otherwise sound membrane. Replace the roof when the membrane has multiple blisters, when the insulation below reads wet on a moisture scan, or when the assembly has been patched across more than roughly a quarter of its area. Axion Roofing photographs the deck condition and gives you the reasoning in writing.
Storm punctures needing same-day protection fall under emergency roof repair in Calgary. Larger buildings and multi-unit properties are handled through commercial roofing in Calgary.
Request a free roof estimate in Calgary for a low-slope scope, or review the full range of Calgary roofing systems Axion Roofing installs.
Sources
- National Building Code, Alberta Edition, Division B, Section 9.19 Roof Spaces.
Free estimate
Get the low-slope section scoped properly
Flori inspects the roof, the flashing and the attic, then issues a written scope. No deposit before the scope is agreed.