Flat Roof Coating for Ottawa Commercial Buildings

What does GoNano's flat roof treatment actually do?

This is a nano roof treatment for elastomeric membrane roofing, and it is not a surface application. It penetrates deep into the membrane and makes it hydrophobic, rather than laying a new skin over the top and asking that skin to hold. We apply it in Ottawa on membrane roofs that are still structurally sound.

That distinction is worth understanding before you compare quotes, because it is the opposite of what most flat roof coatings do. A flat roof deck moves: it expands in July, contracts in January, and flexes every time the temperature crosses zero, and a membrane that has hardened splits under that movement, usually at the seams and at the base of curbs where the stress concentrates. A film-forming product is relying on the film to survive all of that. This treatment works on the membrane itself: it fortifies the matrix instead of covering it, so there is no new skin on the roof to fail, lift or delaminate later.

The treatment does three things. It makes the membrane hydrophobic, which is the waterproofing part. It fills microfissures so freeze-thaw cycling has less to work on. And it reflects UV rays to limit heat absorption and aging, which is what dries and embrittles a membrane over time. It extends the service life of the roof by up to 15 years, and certain conditions apply to that figure.

Which flat roof systems can PROTEXA coat?

Elastomeric membrane roofing, on a membrane that is still structurally sound. We confirm the membrane type on the roof at the free inspection before we quote anything. Single-ply systems such as TPO, EPDM and PVC, sprayed polyurethane foam and metal roofs are outside what we apply this treatment to, so ask before assuming a building qualifies.

If your portfolio is mixed, this matters more than it looks. A property manager with six buildings can easily have three membrane types across them, and the answer is genuinely different per roof. Nothing is lost by asking: the inspection is free and we will tell you a roof is outside scope rather than treat it anyway.

Does a roof coating fix ponding water?

No. Ponding is a slope and drainage problem, and no roof treatment changes the slope of a deck or the position of a drain. Standing water has to be corrected by drainage work or by replacement before treating the roof is worth doing. Areas that hold water after a rain are identified during the inspection.

On an Ottawa roof ponding is not just a wear issue, it is a winter issue. Water that sits in a low spot freezes, expands, and pries at whatever it is sitting on, then thaws and refreezes with the next swing in temperature. A pond over a lap is one of the more reliable ways to open that lap. Blocked or ice-choked drains and scuppers do the same thing at a larger scale during a thaw, because the meltwater has nowhere to go and backs up across the field of the roof.

The practical order of operations is: get the water moving first, then talk about coating. Clearing drains, correcting a sump, adding a cricket behind a large rooftop unit and repairing a settled area are drainage work, and they belong ahead of any surface treatment. A roof that dries out within a day or two of rain is a straightforward coating candidate. A roof with permanent standing water is a conversation about the deck.

Does a flat roof coating reduce summer cooling costs?

Not in a way you should budget against. There is no cool-roof or SRI rating behind this treatment, so do not build an energy business case on it. What the treatment does is reflect UV rays to limit heat absorption and aging.

Two honest caveats for anyone building a business case on this. First, Ottawa is a heating-dominated climate. A cooling saving is real in July but it is not the same lever it is in a southern city, and a lower rooftop temperature in January is not a benefit. Second, the durability argument is the real one anyway: a membrane that absorbs less heat ages more slowly, and thermal cycling across a smaller range puts less strain on the seams. Treat reduced heat absorption as a service-life effect with a possible cooling side benefit, not the other way round.

What does an Ottawa winter do to a flat roof?

Ottawa flat roofs fail at the seams and the details, and the mechanism is freeze-thaw cycling rather than any single cold snap. Meltwater works into a lap or a flashing joint during a mild afternoon, freezes overnight, expands, and widens the opening by a fraction. Repeat that through a shoulder season and the fraction becomes a path.

The rest of the winter load stacks on top of it. Snow sits on a flat roof rather than sliding off, so the deck carries weight for months and the membrane stays wet under it. Ice builds at drains, scuppers and low points, which is exactly where you least want water held. Spring melt then delivers the whole winter's water to the drainage system over a few days. And roof crews and snow removal add traffic to a surface that is already at its most brittle.

This is the case for treating the field of the roof rather than patching. Patching addresses the seam that has already opened. Treating the whole membrane addresses every seam on the roof, including the ones that have not opened yet, which is the difference between reactive and planned maintenance on a building you intend to hold.

When should a commercial flat roof be replaced instead of coated?

Replacement is the right call when the problem is below the membrane rather than on it: saturated or compressed insulation, a soft or rotted deck, active leaks that have already reached the interior, widespread blistering or delamination of the cap sheet, or failed flashings and curbs across the roof. This treatment restores a roof that is still sound. It does not dry out wet insulation and it does not rebuild a failed assembly.

Signals that point at replacement rather than coating:

• Wet insulation. If the insulation under the membrane has taken on water, treating over it leaves the water where it is and the roof keeps deteriorating out of sight.
• A deck that gives underfoot. Softness or deflection is a structural finding, not a surface one.
• Leaks that are already inside. Ceiling tiles, tenant complaints and stained deck edges mean the assembly is compromised, not just weathered.
• Blistering or delamination across the field. The treatment needs a sound membrane to penetrate. It cannot re-adhere a cap sheet that has released.
• A roof at the end of its design life with a known history of repairs. At that point the coating spend competes with a replacement you are going to do anyway inside a few years.

Not every roof qualifies, and the inspection exists to sort that out before anyone quotes a coating. We would rather tell you to budget a replacement than take money for a treatment that will not hold. If your roof is on the line between the two, the coating versus replacement comparison for Ottawa buildings walks through the decision in more detail.

What happens during the roof inspection before a quote?

A crew member goes on the roof, assesses the membrane at no charge, and provides photographs of the roof's current condition. Those two things are the deliverable of the visit, and you get them whether or not the roof turns out to be a coating candidate.

The visit follows the same three-step process we use on every job:

1. Free roof assessment. We verify the roof's condition on site and document it with photographs, rather than quoting from an aerial image or a phone call.
2. Prep and repair. If the roof qualifies, we carry out any necessary minor repairs and clean the surface thoroughly so the treatment goes onto sound membrane.
3. Protective treatment. We apply the treatment across the prepared membrane.

For a commercial building, bring the roof's history to the visit. Age of the membrane, what has been repaired and when, where the leaks have shown up inside, and the drawings if you have them. It changes the assessment materially, and it is the difference between a quote based on what is visible and a quote based on what is actually there. Book it through the free on-site estimate request.

How much disruption does a flat roof coating cause to tenants?

Coating is exterior work carried out from the roof, so tenants keep working and the building stays open. There is no tear-off, so there is no debris chute, no roll-off bin cycling through the parking lot and none of the noise of a deck being stripped. Roof access, hoisting, parking for the crew and any air intakes that need to be managed during application are agreed before the date is booked.

This is usually the deciding factor for occupied buildings, and it is worth weighing against the replacement alternative honestly. A tear-off puts the deck open to the sky in stages, generates weeks of noise directly over occupied space, consumes ground-level laydown area, and carries real weather risk while the assembly is open. A coating carries none of that. For a medical or professional tenancy where downtime is expensive, the disruption difference can outweigh a fair part of the cost difference.

On a house the treatment goes on in a single day. A commercial roof is scheduled against its own area and its own access, so the duration and any phasing by roof section are set at the assessment rather than promised in advance.

When can a flat roof be coated in Ottawa?

In the frost-free part of the year rather than in winter, because the treatment needs a dry, clean surface and a stretch of mild weather to cure. Late-season bookings depend on overnight temperatures and on the forecast for the cure window, so the realistic date is set at the assessment once we have seen the roof.

Practically, that means a building with a 2026 roof line item should be getting inspected early in the season rather than in October. The inspection is the free part and it has no calendar constraint. What has a constraint is the application, and the good bookings in the Ottawa season go early. If the inspection finds replacement rather than coating, you also want that answer while there is still budget cycle left to act on it.

What determines the cost of a flat roof coating?

The building does: total roof area, the condition of the existing membrane, how much cleaning and how many seam or flashing repairs are needed first, the number of curbs, drains, penetrations and rooftop units the crew has to detail around, and how the crew and material get onto the roof. We price it after we have been on the roof rather than over the phone. The on-site assessment is free and carries no obligation.

The variable that surprises people is detailing. Two roofs of identical area price differently when one is a clean rectangle and the other carries eight rooftop units, a screen wall, three vent stacks and a skylight, because every one of those is a hand-worked perimeter rather than a rolled field. Access is the second one: interior stair access with a small hatch and no place to park a lift is a different job from a roof a crew can reach directly. The full list of factors is set out in the guide to what determines roof coating cost in Ottawa.

For a capital planning conversation, the framing that matters is not the coating price on its own. It is the coating spend, plus the years it adds, set against the replacement you would otherwise fund and the year you would otherwise fund it in. That comparison needs a real number for your roof, which is what the free inspection produces.

Is there a warranty on a commercial flat roof coating?

Up to the 15 year mark, but the roof decides it. We assess the membrane, the seams and the drainage on site first, then confirm what applies to your building in writing before the crew is booked.

Where in the Ottawa area is this available?

We treat commercial flat roofs across Ottawa, Kanata, Nepean, Barrhaven, Orleans, Gloucester and Stittsville. The inspection is done on the roof, so we see the actual membrane, the drains and the access before quoting anything.

PROTEXA is a certified GoNano contractor and is listed in GoNano's dealer locator. We do not simply sell the product: we assess the roof at no charge, handle the prep, and apply the treatment on site. For building owners with sloped asphalt shingle roofs in the same portfolio, the same approach applies through GoNano NuRoof Fortify for asphalt shingle roofs, and concrete walkways, entrances and pads are covered by concrete sealing.

Common questions from Ottawa property managers