Flat Roofing Winnipeg | Commercial & Residential SBS Torch-On Systems

Soprema torch-on roofing systems engineered to handle Winnipeg winters, spring melt, and summer heat — installed by factory-authorized applicators. Your flat roof faces the most brutal conditions in Manitoba—standing water, ice pressure, and extreme UV rays. At Alpha Roofing, we specialize in SOPREMA SBS Modified Bitumen systems, the heavy-duty standard for architects and engineers. As Factory-Authorized Applicators, we ensure your flat roof isn't just a layer of plastic, but a fully engineered water-shedding system built to last 20+ years.

FULL SCOPE OF WORK
What's Included in a Flat Roof Replacement

✅  Full tear-off of existing membrane, insulation, and flashings
✅  Thorough inspection of roof deck for rot, soft spots, or structural damage
✅  Soprema self-adhered base sheet mechanically fastened to deck
✅  Soprema SBS modified bitumen cap sheet — torch-applied for a seamless watertight bond
✅  All flashings replaced at parapet walls, drains, skylights, and penetrations
✅  Premium drainage slope assessment — water must never pond on a flat roof
✅  Full property cleanup and haul-away of all old materials
✅  Final inspection and written workmanship warranty issued before we leave

We Are a Soprema Authorized Applicator

Soprema authorized applicator status is earned, not bought. Our crew completed factory training, our work meets Soprema’s standards, and your roof qualifies for a manufacturer-backed warranty plus our workmanship warranty.
Soprema is one of the world’s largest roofing and waterproofing manufacturers, with systems used in over 90 countries. Their SBS modified bitumen system is a proven flat roofing solution for Canada’s climate, and Alpha Roofing is among the Winnipeg contractors approved to install it.

Soprema Warranty — What It Covers

✅  Manufacturing defects in Soprema membrane materials
✅  Labour costs to repair or replace defective materials
✅  Watertight performance for the full warranty term
✅  Coverage transferable to new owner — adds value when you sell
✅  Backed by Soprema's global manufacturing guarantee
✅  Combined with Alpha Roofing's written workmanship warranty for complete protection

YOUR PROTECTION
Premium Soprema® SBS Flat Roof Systems

A flat roof isn't just a single membrane — it's a complete system where every layer works together to stop leaks, manage water, and protect the structure below. Snow load, freeze-thaw cycles, UV exposure, and standing water all take their toll. If one layer fails, the rest is at risk.
At Alpha Roofing we install flat roofs as a full Soprema system — each layer engineered to work with the next, from deck prep and vapour control through insulation, base sheet, cap sheet, flashings, and drainage. Compatible components mean better adhesion, stronger seams, and longer service life. Here's what a properly installed Soprema flat roof includes:

TOTAL SYSTEM COVERAGE
A Multi-Layered Defense Against Winnipeg Weather

SBS Cap Sheet (Granulated):
Soprema's torch-applied cap membrane forms the visible, weather-facing surface. SBS polymer modification gives it rubber-like flexibility — it expands and contracts with Winnipeg's extreme temperature swings without cracking or splitting.

SBS Base Sheet:
Mechanically fastened to the roof deck, the base sheet is the foundation of the 2-ply system. It provides the primary structural layer and creates the substrate that the cap sheet bonds to for a seamless, fully-adhered assembly.

Rigid Polyiso Insulation (ISO):
Closed-cell polyisocyanurate (polyiso) insulation installed above the deck provides the thermal performance your flat roof needs to significantly reduce your heating and cooling costs while providing a rock-solid substrate for the membrane.

Vapour Barrier:
In Winnipeg's -30°C winters, warm indoor air wants to escape through your roof. Without a Soprema vapour barrier, this creates condensation that rots your deck from the inside out. We seal your building envelope correctly, every time..

Drainage & Slope:
Water must move. We assess and correct drainage on every project — proper slope to drains or scuppers prevents the ponding water that degrades membrane and causes leaks faster than anything else.

Flashings & Terminations:
Every edge, wall, drain, skylight, and penetration is a potential entry point for water. Soprema flashing membranes and metal terminations seal these transitions permanently — this is where most flat roof failures begin, and where we pay the most attention.

EXPERTISE AT EVERY SCALE
Winnipeg Trusted Residential & Commercial Flat Roofers

Alpha Roofing handles both residential and commercial flat roofing projects across Winnipeg and surrounding areas. Whether it's a single-family home addition, a commercial building, an apartment complex, or a garage roof — the Soprema SBS system performs equally well on every scale. Our crew is trained and equipped for projects of all sizes, and we carry $5 million in liability insurance for complete peace of mind on any commercial job.

START WITH AN HONEST ASSESSMENT
Book Your Free Roof Inspection & Custom Quote

We'll come out, inspect your roof, and give you a detailed written quote — no pressure, no sales tactics. Most inspections take under 30 minutes.

✅  Response within 24 hours
✅  Written quote, no surprises
✅  WCB insured crew
✅  No obligation, no pressure
✅  Serving all of Winnipeg & surrounding area

KNOW BEFORE IT GETS WORSE
Signs Your Flat Roof Needs Attention

Winnipeg's climate puts flat roofs under pressure year-round. Long winters, heavy snow loads, freeze–thaw cycles, strong winds, and sudden summer downpours all take a toll. Unlike pitched roofs where damage is often easy to spot from the ground, flat roof problems can develop slowly and stay hidden until leaks show up inside. Water doesn’t run off as quickly, so even small issues can turn into costly repairs if ignored.

Warning Signs Your Flat Roof is Failing:

❌ Ponding water that remains 48+ hours after rain or snowmelt
❌ Bubbles, blistering, or raised sections in the membrane surface
❌ Cracks, splits, or exposed granules washing into drains
❌ Water stains, mold smell, or wet insulation visible on ceilings below
❌ Soft or spongy spots when walking on the roof
❌ Membrane pulling away from parapet walls, curbs, or flashings
❌ Rust staining around drains, scuppers, or metal flashings
❌ Loose seams or open laps in torch-on or membrane systems
❌ Excessive ice buildup along edges during winter
❌ Roof is 15+ years old — even if it appears intact from below

Not sure if you need a repair or a full replacement? We’ll provide a free, honest assessment of your roof’s condition. Often, a targeted repair can significantly extend your roof's life—we’ll give you a straight answer with zero pressure.

Request Flat Roof Evaluation →