What is a Cool Roof Coating

A cool roof coating is a liquid-applied elastomeric membrane, usually white, rolled or sprayed over an existing roof surface. The coating bonds to the substrate, cures into a flexible monolithic skin, and reflects 75 to 90 percent of incoming solar radiation. Most coatings used in the GTA are one of three chemistries:

• Acrylic. The most common, lowest cost, breathable. Best for sloped roofs and dry climates. Limited ponding water resistance, which matters on flat roofs.
• Silicone. The premium choice for flat industrial roofs. Excellent ponding water resistance, holds reflectivity for 15+ years without yellowing, and bonds to almost any substrate including weathered single-ply.
• Polyurethane. Highest impact and abrasion resistance. Used on roofs with foot traffic or hail exposure. Higher cost and harder to recoat in 10 years.

How Much Energy a Cool Coating Actually Saves

The Lawrence Berkeley National Laboratory cool roof studies (replicated by ENERGY STAR) consistently find 10 to 30 percent reductions in summer cooling load on coated buildings versus uncoated dark roofs. On a 100,000 square foot Toronto warehouse with 200 tons of installed cooling, that translates roughly to:

• 15 to 25 percent lower peak demand in July and August (smaller demand charges)
• $8,000 to $20,000 per year in cooling-related electricity savings, depending on building use, insulation, and HVAC efficiency
• Surface temperature drops of 30 to 40 degrees Celsius at peak
• Roof membrane lifespan extension of 5 to 10 years (the coating absorbs the UV the membrane no longer has to)

For air-conditioned facilities the math is direct. For unconditioned warehouses, the savings come indirectly through worker comfort, less product heat damage, and slower membrane aging. If you’re looking to get your flat roof professionally fixed, let our team with 50+ years of experience get the job done quickly, safely, and properly!

When a Coating is the Right Answer

Cool coatings are the right answer when:

• The existing membrane is structurally sound but UV-aged, chalky, or losing reflectivity
• The roof is not leaking widely (small repairable leaks are fine, widespread saturation is not)
• Insulation is dry (verified by infrared scan and core samples)
• The building owner wants 10 to 15 more years out of the existing assembly before committing to a re-roof
• The building has air conditioning load worth lowering, or qualifies for Toronto Green Standard credit

Coatings are the wrong answer when:

• The insulation is wet anywhere on the roof (a coating will trap the moisture and accelerate deck corrosion)
• The membrane has more than 10 percent of its area in active failure
• Seams are open or fasteners are backing out
• Drainage is broken (coating cannot fix slope)

An honest pre-coating inspection always includes an infrared moisture scan and core samples. Skip that step and the coating becomes a 5-year mistake instead of a 15-year extension.

Toronto Green Standard and Incentive Programs

The Toronto Green Standard sets a minimum solar reflectance index (SRI) on roofs for new construction and many major retrofits inside the City of Toronto. White cool roof coatings on aged commercial roofs are one of the cheapest ways to bring an existing building up to the SRI threshold, particularly when paired with energy retrofit financing. The ENERGY STAR roof products program certifies coatings that meet a baseline reflectance and emittance and is the easiest credential to use when documenting a coating for green building certifications.

Save On Energy and various IESO retrofit programs in Ontario have historically offered rebates on cool roof installations as part of broader energy retrofit packages. Programs change yearly, so confirm current incentives with your roofing contractor or energy consultant before pricing the project.

Building Code and Warranty Considerations

Cool roof coatings are recognized under the Ontario Building Code as roof restoration systems and do not by themselves require a building permit. Any work that affects the structural deck, drainage, or insulation does. The bigger watch-out is membrane warranties: applying a coating over a single-ply membrane that is still under manufacturer warranty often voids the warranty. Always check the existing manufacturer’s recoat policy before committing. Some manufacturers explicitly approve coatings as a service-life extension and will register the coating into the existing warranty.

What a Coating Project Looks Like

A typical 50,000 square foot coating job on a GTA warehouse takes 5 to 10 working days, depending on weather and surface prep. The sequence is:

1. Pre-project inspection: infrared scan, core samples, drainage check, membrane probe
2. Repair scope: patch active leaks, replace wet insulation cuts, re-attach loose flashings
3. Pressure wash and detergent clean, full surface dry
4. Primer if the substrate requires it (silicone needs none; acrylic over old EPDM needs a primer)
5. Base coat application by spray or roller at the manufacturer-specified mil thickness
6. Cure time, then topcoat at the second specified mil thickness
7. Final wet-mil and dry-mil thickness verification, photo documentation, warranty registration

Lifespan and Recoat Schedule

A properly installed silicone coating on a flat industrial roof in the GTA holds up for 15 to 20 years. Acrylic coatings hold for 10 to 12 years. Polyurethane holds for 12 to 15 years and tolerates more abuse. All coatings can be recoated at the end of their life rather than removed, which means the building moves into a perpetual renewal cycle of 15-year coating extensions instead of 25-year tear-offs. For long-hold industrial owners, that math is significantly cheaper over a 50-year horizon than the conventional re-roof cycle.

Get a Coating Evaluation for Your Roof

If you have a 10 to 20 year old commercial roof in the GTA that is structurally sound but losing performance, a cool roof coating can buy you another decade of service for a quarter of the cost of a re-roof, with energy savings on top. Industrial Roofing Services Limited has been coating and restoring industrial roofs across Southern Ontario since 1973, and we always start with a moisture scan and core sample before quoting. request a free quote and we will tell you honestly whether a coating or a re-roof is the right answer for your building.

Frequently asked questions

Can I coat a TPO roof?

Yes, with a silicone coating and the proper primer. Manufacturer approval is required to maintain any remaining warranty. Do not coat a TPO roof that is less than 8 years old without checking with the membrane manufacturer.

Will a cool coating cool my warehouse without air conditioning?

Yes, but indirectly. Surface and roof deck temperatures drop 25 to 35 degrees Celsius. Inside air temperature drops 3 to 8 degrees Celsius depending on insulation and air change rates. For warehouses without air conditioning, the worker comfort and product protection benefit is meaningful but harder to monetize than HVAC savings.

Does a cool roof void my existing membrane warranty?

Sometimes. Always check with the original manufacturer before applying any coating. Some manufacturers (Carlisle, GAF, Firestone) have approved restoration coating programs that maintain the warranty. Others void it on contact.

What about ponding water?

Silicone is the only coating chemistry that handles long-term ponding without breaking down. If your roof has chronic ponding (no drainage repair planned), specify silicone. Acrylic will fail at the ponding edges within 3 to 5 years.

Can a coating fix an active leak?

A coating patches small leaks at penetrations and minor seam openings. It cannot fix wet insulation, broken drains, structural movement cracks, or large membrane failures. Repairs go in before the coating, not after.

The post Cool Roof Coatings vs Re-Roofing for Industrial Buildings appeared first on Industrial Roofing.

The Quick Answer

Most GTA commercial buildings under 100,000 square feet end up with TPO. It is the cheapest of the three, welds clean, and the warranty options are now competitive with PVC. EPDM still wins on a few specific buildings (cold-only environments, simple geometry, owners who plan to hold the building 20+ years and do not mind a black roof). PVC wins where there are rooftop chemical exhausts, kitchen grease vents, or rooftop solar panels going in. It may seem simple, but there’s more to this than you think.

What Each Membrane Actually is

TPO (thermoplastic polyolefin)

A blend of polypropylene and ethylene-propylene rubber, reinforced with a polyester scrim. Comes off the roll white (the most common colour in the GTA), grey, or tan. Sheets are seamed with hot-air welding which creates a chemical fusion stronger than the membrane itself. Average installed thickness is 60 mil for commercial work, 80 mil where the warranty calls for it.

EPDM (ethylene propylene diene monomer)

A synthetic rubber, almost always black, sometimes white-coated. The original “rubber roof” that took over the North American flat roof market in the 1980s. Sheets are seamed with adhesive tape and primer rather than heat-welded. Standard thickness is 60 mil, with 90 mil available where impact resistance matters.

PVC (polyvinyl chloride)

A thermoplastic membrane reinforced with polyester or fibreglass. White or grey on most GTA installs. Hot-air welded like TPO. Standard thickness 50 to 80 mil. PVC was the original single-ply heat-welded membrane, and it is still the gold standard for chemical and grease resistance.

Lifespan and Warranty

All three membranes carry 20 to 25 year manufacturer warranties when installed by a certified contractor. Based on our team’s experience, this is what we found for real world cases.

• EPDM: 20 – 25 years years on a well-maintained roof. The longest service life of the three. Black EPDM gets brittle after about 25 years but rarely fails catastrophically.
• PVC: 25 years. The plasticizers in older PVC formulations migrated out of the membrane and caused shrinkage at corners. Modern PVC formulations have largely solved this.
• TPO: 20 years on the newer formulations (post-2010). Earlier TPO had real durability problems and a deserved bad reputation. The current generation is significantly improved.

Chemical and Grease Resistance

This is the single biggest reason to pick PVC over TPO. Animal fats, kitchen grease, jet fuel, and many industrial solvents will degrade TPO and EPDM but have almost no effect on PVC. If your building has rooftop kitchen exhausts, food processing, or chemical exhaust stacks, the membrane around those penetrations needs to be PVC even if the rest of the roof is TPO. Most roofers will install PVC walk pads and curb wraps in those zones as a hybrid solution.

Energy Performance and Cool Roofs

White TPO and white PVC reflect 75 to 85 percent of incoming solar radiation. Black EPDM reflects under 10 percent. On a hot Toronto July afternoon, a black EPDM roof can run 70 to 80 degrees Celsius on the surface while a white TPO next door runs 35 to 40 degrees. That heat transfers through the deck into the building and into the HVAC load. For air-conditioned warehouses and distribution centres, the cooling savings on a white roof typically pay for the membrane upgrade within 8 to 12 years. White-coated EPDM exists but commands a premium that erases the cost advantage.

Wind Uplift and Storm Performance

All three membranes can pass FM Global wind uplift testing for the GTA wind zone. The difference is in the installation method. Mechanically attached single-ply (TPO and PVC) handles wind uplift through fastener spacing engineered to the deck and the building height. Fully adhered systems use bonding adhesives. Ballasted EPDM relies on the ballast weight, which is the reason many newer GTA buildings cannot use it. After the major windstorms of 2018 and 2022 in Southern Ontario, several improperly designed ballasted roofs lost ballast over the parapet, exposing the membrane to point loads.

Welding and Seam Reliability

This is where TPO and PVC have a real advantage over EPDM. A hot-air weld at 540 degrees Celsius fuses two sheets into a single piece of plastic. The seam is stronger than the membrane itself, and a proper welder can probe-test every seam before leaving the roof. EPDM seams use seam tape with primer. The tape is reliable when installed correctly, but adhesive seams are slower to inspect, and any contamination during application creates a weak point. Over 25 years on a roof, the most common EPDM failure mode is tape seam separation at corners and penetrations.

Which membrane to Pick

• Standard GTA warehouse, distribution centre, big box retail: TPO. Best price, best welding, current formulations are reliable, white reflects heat. Pick a tier-one manufacturer and install at 60 mil minimum.
• Long-hold owner, simple roof, no rooftop equipment, comfortable with black: EPDM. Longest service life, lowest maintenance over the holding period, and the simplest field-installed system in the trade.
• Restaurant, food processing, industrial chemical exhaust, rooftop solar: PVC. The chemical resistance and weldability are worth the premium, and PVC is the only membrane some solar manufacturers will warrant against.
• Cold storage warehouse: Either TPO or PVC, fully adhered, with vapour control on the warm side of the insulation. EPDM is harder to detail at the cold-side penetrations.

Good Installation vs a Bad One

Membrane choice matters less than installation quality. The same TPO that lasts 20 years on a careful install will fail in 8 years on a sloppy one. Look for:

1. Manufacturer certification of the installing contractor (not just the company, the foreman on your job).
2. Proper insulation board layout with staggered joints and full coverage adhesive or fastener pattern.
3. Detailed flashing at every penetration, parapet, and equipment curb. Field welds at corners, not patched membrane.

Final Thoughts

Every GTA commercial building has a single membrane that is the right answer when you weigh cost, lifespan, energy savings, and the equipment on the roof. Industrial Roofing Services Limited has installed all three systems across Southern Ontario since 1973, and we will give you a comparison quote across TPO, EPDM, and PVC for the same scope before you commit. request a free quote and we will walk through your roof, and put real numbers against each option.

Frequently Asked Questions

Is white TPO required by Toronto Green Standard?

Toronto Green Standard requires a minimum solar reflectance index (SRI) on roofs for new construction and major retrofits in many zones. White TPO and white PVC meet the requirement. Black EPDM does not. White-coated EPDM does. Check with your designer for your specific building tier under the standard.

How thick should my membrane be?

60 mil is the standard for commercial work in the GTA. 80 mil is recommended for high-traffic roofs (frequent maintenance access), high-hail-risk locations, or any building where a 30-year warranty is on the table. The cost increase from 60 to 80 mil is usually 15 to 20 percent and is almost always worth it on a building you plan to hold for two decades.

What about ballasted EPDM over insulation?

Older buildings with deck capacity for ballast can still use it. New steel decks rarely have the structural margin. Always have the structural engineer sign off on dead load before specifying ballast on any post-1990 building.

Do single-ply roofs need maintenance?

Yes. Twice-yearly inspections, drain cleaning, and seam checks at penetrations are standard. A maintained roof routinely outlasts its warranty. An ignored roof routinely fails inside the warranty period and the manufacturer voids the claim because of the lack of maintenance records.

The post TPO vs EPDM vs PVC Roof for GTA Commercial Buildings appeared first on Industrial Roofing.

The tricky part? Most warning signs of winter damage don’t jump out right away. They show up quietly in ceiling tiles, drainage systems, or small shifts in the roof deck before they turn into costly repairs. Over the years, we’ve seen building managers miss early signals, only book commercial roofing services once leaks were already dripping on office equipment or tenants were complaining.

Below are the top warning signs we recommend keeping an eye out for this winter, along with what they mean, and what you can do to prevent them from getting worse.

1. Sagging or Bowing Roof Sections

When snow builds up, especially during back-to-back storms, the extra weight can cause parts of the roof to sag. It doesn’t always collapse right away, but sagging is the early red flag. We’ve seen this most often on older buildings where the support structure is already under strain.

Why it’s a problem:

A sagging roof deck means the load is too much for the structure. Left alone, it can compromise the integrity of the roof or even lead to partial collapse.

What to do about it:

• Schedule a professional inspection after major snowfalls.
• Clear snow from the roof safely – always book a professional to do this.
• Consider adding tapered insulation during your next roofing project. It not only helps with drainage but can also spread loads more evenly.

2. Ice Dams and Blocked Drainage

Flat roofs rely on clear drains and scuppers to move water off the surface. When snow melts and then refreezes, water can pool and create ice dams. We’ve seen drains frozen solid, with water backing up and sitting on the roof for days.

Why it’s a problem:

Standing water seeps into seams and small cracks. Once it freezes again, it pushes those gaps wider, making leaks inevitable.

What to do about it:

• Have drains and scuppers checked and cleared regularly.
• Make sure heat loss from the building isn’t causing uneven melting.
• Get a roofing contractor to inspect and reseal vulnerable areas before winter hits.

3. Water Stains or Leaks Inside the Building

One of the most common calls we get in winter comes after someone notices ceiling tiles sagging or water dripping inside. By that point, the problem had started weeks earlier on the roof.

Why it’s a problem:

Interior leaks don’t just damage finishes. They can take out insulation, wiring, and even compromise structural elements if left untreated.

What to do about it:

• Don’t just replace the tile and forget about it. Find the source.
• Have a professional trace leaks to their entry point on the roof.
• Schedule regular mid-winter inspections – not just in the spring.

4. Cracks in Walls or Ceilings

This is one thing people don’t always connect to roofing. We’ve walked into commercial spaces where the manager was worried about drywall cracks, not realizing they were a symptom of roof stress.

Why it’s a problem:

Shifting loads on the roof can push down on walls, causing cracks inside. It’s an early signal that something above isn’t holding up as it should.

What to do about it:

• Treat structural cracks seriously.
• Call in both your roofer and, if needed, a structural engineer.
• Keep up with snow removal and inspections to prevent overload.

5. Damaged Gutters and Eaves

Even on flat roofs, eaves and edge details take a hit in winter. Heavy icicles or expanding ice can tear gutters away from the building.

Why it’s a problem:

Once gutters pull loose, water flows where it shouldn’t – down walls, into foundations, and around entrances. That creates safety hazards and building damage.

What to do about it:

• Inspect gutters and downspouts after each major storm.
• Don’t chip away at ice – it often does more harm than good.
• Get a professional crew to handle ice safely and repair damage right away.

6. Sprinkler Heads or Ceiling Tiles Sagging

This one often surprises people. If your fire suppression system or drop ceiling tiles are sagging, it’s often because the roof above is stressed. We had a client last winter whose sprinkler pipes nearly burst because of the extra pressure from the snow load.

Why it’s a problem:

It’s both a roof issue and a safety issue. Sagging sprinkler heads can signal dangerous stress on the structure.

What to do about it:

• Never ignore changes in your ceiling system.
• Call a roofing professional to check for load issues.
• Keep up with proactive snow removal before systems are put at risk.
• Staying Ahead of Winter Roof Damage

The best prevention is planning ahead. Waiting until after a storm to act usually means waiting in line with every other business owner who’s just discovered a problem. By scheduling flat roof inspections, clearing snow and ice safely, and keeping drains clear, you can avoid the majority of winter roof failures we see each year.

At Industrial Roofing Services Limited, we’ve been working on commercial flat roofs in Toronto and across Southern Ontario for over 45 years. We know the warning signs, and we know how to address them before they turn into major disruptions. Our team is fully licensed, insured, and trained to handle everything from routine maintenance to emergency repairs – all with strict safety standards in place.

If you manage a commercial property and want to make sure your roof is ready for winter, reach out for a free consultation. We’ll walk you through what to watch for and build a plan that keeps your building safe, dry, and open for business all season long.

The post Winter Roof Damage: Warning Signs For Commercial Properties appeared first on Industrial Roofing.