Every system, no favourites
We work with all six major low-slope systems, so the recommendation follows your building, not our stock.
Flat roof systems
Commercial Flat Roofing in Edmonton
Six low-slope systems, one hard climate. Here is how to match the membrane to your building, your budget and an Edmonton winter.
- Every major low-slope system
- ARCA warranty eligible
- Built for freeze-thaw
Overview
Commercial flat roofing in Edmonton has to survive conditions a mild-climate roof never sees: months of snow load, repeated freeze-thaw at every seam and drain, a spring melt that finds any low spot, and summer hail. The system you choose is the biggest decision on a re-roof or new build, and it sets your maintenance budget for the next 20 to 30 years.
There is no single best membrane. The right choice depends on your deck, your rooftop equipment and foot traffic, what comes out of your exhaust fans, how long you plan to own the building, and the warranty your owner or lender expects. Below is a plain comparison of each system, including where it is not the right fit.
Built for Edmonton weather
Every spec starts with snow load, drainage, freeze-thaw and hail, then works back to the membrane.
Warranties in writing
Manufacturer, workmanship and ARCA coverage spelled out before you sign, not after.
Behind the roof for its life
Inspections, maintenance and repairs for as long as the roof is on the building.
Explore
Everything under flat roofing
Compare every commercial flat roof system and see which one suits your building.
Flat roof system
SBS torch-on
Two-ply modified bitumen, the proven Alberta standard for hail, cold and rooftop traffic.
Flat roof system
TPO
Heat-welded single-ply membrane built for large, open warehouse and distribution roofs.
Flat roof system
EPDM
Synthetic rubber membrane that stays flexible in deep cold, with few seams and a long record.
Flat roof system
PVC
Heat-welded single-ply membrane for roofs exposed to grease, oils and chemical exhaust.
Flat roof system
Built-up (tar and gravel)
Repair, maintenance and replacement for the tar and gravel roofs on older Edmonton buildings.
Flat roof system
Inverted roofs
Protected membrane roofs for concrete decks, plazas and parkades, with the membrane shielded from weather.
Metal roofing and cladding
Metal roofing and cladding
Standing seam metal roofs and wall cladding for sloped roofs, canopies and industrial envelopes.
How to choose a commercial flat roofing system in Edmonton
Start with the building, not the brochure. These six questions narrow the field quickly, and we answer them on site with core cuts and a drainage check before recommending anything.
- Deck and structure: steel, concrete or wood, and how much weight it can carry.
- Traffic: how often trades walk the roof to service rooftop units.
- Exposure: grease, oils or chemicals from exhaust fans and process vents.
- Hot work: whether open flame is allowed on your site.
- Warranty: the length and type your owner, lender or tenant requires.
- Life-cycle cost: first cost against service life and maintenance.
Asphalt-based systems: SBS 2-ply and built-up
SBS modified bitumen in two plies is the regional workhorse. It stays flexible in the cold, shrugs off foot traffic and holds up well to hail. Built-up tar and gravel roofs are still common on older Edmonton buildings, but most owners now repair them or replace them with SBS rather than install new.
Single-ply membranes: TPO, EPDM and PVC
Single-ply sheets go down faster with fewer seams, which keeps costs down on large, simple roofs. TPO suits big distribution buildings. EPDM rubber stays flexible in deep cold but does not tolerate oil or grease. PVC costs more and is the right call where kitchen, food or chemical exhaust lands on the roof.
Inverted roofs and metal
Inverted (protected membrane) roofs put the insulation on top of the waterproofing, which shields it from hail, UV and freeze-thaw. They suit concrete decks, plazas and parkades, but the ballast is heavy. Standing seam metal is a sloped-roof and wall system; it pairs well with flat roofs on canopies, mansards and cladding.
Warranty and life-cycle cost
A commercial roof can carry three layers of warranty: the manufacturer's material or no-dollar-limit (NDL) system warranty, the contractor's workmanship warranty, and an ARCA third-party warranty of 5, 10 or 15 years. Rain Roofing issues a 10-year workmanship warranty and is an ARCA member. The cheapest roof per square foot is rarely the cheapest over 25 years.
Anatomy of a flat roof
What sits between the weather and your building
Every layer has a job. Skip one, or install it carelessly, and the roof fails early. This is the assembly we build and warranty.
- 07Cap sheet or membraneThe weathering surface: granulated SBS cap sheet, or a heat-welded TPO, PVC or EPDM membrane.
- 06Base sheetThe first waterproofing ply, fully bonded and lapped at every seam.
- 05Cover boardA hard, flat surface that protects the insulation from foot traffic and hail.
- 04Tapered insulationBuilt-in slope that moves water to the drains so it never sits and ponds.
- 03InsulationPolyiso boards, staggered so no joint lines up and heat cannot short-circuit.
- 02Vapour barrierStops warm, moist indoor air from condensing inside the insulation in January.
- 01Steel deckThe structure. We check fastening, rust and deflection before anything goes on top.
Systems we install from
Soprema, IKO, Carlisle, GAF, Holcim, Johns Manville, Sika Sarnafil, Firestone
Questions
What facility managers ask us
What is the most common flat roof system on Edmonton commercial buildings?
Two-ply SBS modified bitumen. It has the longest local track record, handles cold and hail well, and most Alberta manufacturers and roofers know it inside out.
Can you put a new roof over our existing one?
Sometimes. A recover works when the deck and insulation are dry. We confirm that with core cuts or a moisture survey first; if the insulation is wet, it has to come off.
Which flat roof system lasts the longest?
Inverted roofs and well-maintained EPDM or PVC often pass 30 years. In practice, drainage and maintenance affect service life as much as the membrane does.
How do we find out which system is right for our building?
Book a roof assessment. We inspect the roof, take cores, check drains and rooftop equipment, and send a written recommendation with options within five business days.
Talk to the crew that stands behind the roof
Send us drawings, a spec or just an address. You get a clear scope, a written warranty and a roofer who answers the phone in a storm.