How to Maintain Commercial Skylights to Prevent Water Intrusion

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The fastest way a small skylight problem turns into a pricey repair is simple: nobody looks at it until water is already dripping onto the floor below. Skylights rarely leak because the glazing itself fails. They leak because the curb around them does: sealant that has cracked and pulled away, counterflashing that has worked loose, or a drain that nobody cleared before the leaves piled up.

Why commercial skylight maintenance can’t wait

A leaking skylight rarely announces itself where the leak actually starts. Water follows the path of least resistance along framing members, insulation, and vapor barriers before it finally shows up as a stain on a ceiling tile, sometimes ten or fifteen feet from the curb itself. By the time anyone notices, wet insulation and a soaked deck have usually been sitting there for weeks.

That lag is exactly why a scheduled walk beats a reactive one. Catching a cracked sealant joint in September is going to be a lot better than in February, after a winter of freeze thaw cycling has widened the gap, tends to mean a wet ceiling, a business interruption, and a much bigger invoice. If you need professional help to fix or replace your leaky skylight, contact us today and we’ll be able to fix your issues ASAP! 

Step 1: Start the inspection from inside

Before anyone gets on the roof, walk the building underneath every skylight. Look at the ceiling tiles, drywall, or exposed deck directly below each unit for staining, discoloration, or a soft spot. A ring shaped water stain almost always means an active or recent leak.

This step takes ten minutes and tells you exactly which skylights need the closest look. It’s also the easiest thing to skip when a facilities team is busy, which is exactly why it gets skipped, and why leaks get found late.

Step 2: Check the curb flashing and sealant

The curb, the raised frame the skylight sits on, is where almost every leak actually starts. Walk the perimeter of each unit and look for sealant that has gone chalky, cracked, or separated from either the curb or the skylight frame. Check that the counterflashing, the metal trim that laps over the membrane, is still snug and not loose.

Flashing is consistently identified as one of the most failure prone details on a low slope roof. The National Roofing Contractors Association’s guidance on roof flashing treats it as its own category of inspection for exactly this reason: it is a joint between two different materials, and joints move differently than the field of the roof around them.

Step 3: Clear the drainage path around every curb

Water that cannot drain away from a skylight curb has more time to find a way in. Clear leaves, granules, and any debris that has built up against the low side of the curb, and confirm the nearest roof drain or scupper is not blocked.

This is also the moment to look for ponding that sits well past the point where the roof should have drained. Standing water against a curb means that seal is under more pressure than it should be, for longer than it should be.

Step 4: Watch for movement from thermal cycling

Roof membranes and metal flashing expand and contract with temperature, and a skylight curb sits at the exact spot where several materials with different expansion rates all meet.That movement can make a sealant joint loose or pull counterflashing away from the fastener line, wearing down over time.

Look for hairline gaps, fasteners that have started to back out of the counterflashing, or a joint that looks slightly different from the same joint on another skylight about the same age. None of these need an emergency call on their own. Together, or left alone for another season, they add up.

Step 5: Build spring and fall walks into the schedule

Two inspections a year catches most of what matters. A spring walk tends to find whatever winter movement opened up. A fall walk confirms drains and curb bases are clear before snow and ice load the roof for months.

Both visits are also a chance to compare current photos against the last set. A joint that looked fine in the fall and looks different in the spring tells you something a single inspection never can: that something changed, and roughly when.

Step 6: Keep a written record, not a memory

A photo, a date, and a one line note for each skylight is enough. Six months from now someone can look at a joint and know if it looks the same, better, or worse than it did last time.

This habit pays off twice. It catches slow moving problems that a single visit would never see, and it gives a roofing contractor a head start.

Common mistakes that undo good maintenance

The most common mistake is not skipping maintenance entirely. It is doing a rooftop walk without ever checking underneath the skylights first, which means small leaks get missed until they show up somewhere else. The second most common mistake is treating a sealant touch up as a permanent fix rather than a stopgap, when the real issue is a flashing detail that needs to be redone properly.

A close third: assuming every skylight on a roof ages at the same rate. Orientation, shade, drainage, and foot traffic all differ from unit to unit, even on the same building. Two skylights installed on the same day can be in noticeably different condition five years later.

When it’s time to call a roofing contractor

A facilities team can handle the inspection routine above without any special tools. Sealant replacement, flashing repair, and curb re-detailing are a different category of work, and they are worth handing to a roofing contractor who does this daily, both for the workmanship and for the fall protection the job requires.

Frequently asked questions

Skylight and flat roof maintenance across Southern Ontario

Industrial Roofing Services Limited maintains, repairs, and inspects skylights and flat roof systems for commercial and institutional buildings throughout the GTA and Southern Ontario, including roofing crews serving Waterloo, Ontario and Fergus, Ontario. If it has been more than six months since anyone looked at your skylights from either side of the roof, get in touch with our team and we will build a maintenance visit around your building’s specific roof.

The post How to Maintain Commercial Skylights to Prevent Water Intrusion appeared first on Industrial Roofing.

Not all flat roofs are truly flat, and tapered insulation installed on your flat roof could be one of the reasons why. It is a layer of rigid insulation cut to a gentle slope, built up across the roof so water is nudged toward the drains instead of sitting in place. The result of some tapered systems may appear level to the eye but quietly sheds water every time it rains. If your building has a low-slope roof that is has standing water 48 hrs after a rain event, then a built-up slope insulation system may be a solution for you.

This guide is about the material itself: what tapered insulation is, how it is designed and laid out, and when it earns its place on a roof. If you are trying to solve ponding in general, that is a broader question we cover separately.

What tapered insulation is

Tapered insulation is rigid board insulation, usually polyisocyanurate, that is manufactured or cut at an angle rather than at a uniform thickness. Lay enough of those angled boards side by side and you create a continuous, gentle slope across an otherwise level deck. The boards are thin at the low points near the drains and thicker at the high points, so the finished surface directs water exactly where you want it.

It is installed between the roof deck and the waterproof membrane, so once the membrane goes on top, none of the slope is visible. From the parking lot the roof still reads as flat. From a raindrop’s point of view, it is a hillside.

Why a flat roof needs built-in slope

Water that sits on a roof is the enemy. Ponding adds weight, accelerates membrane aging under UV, feeds blistering and seam failure, and turns a small leak into standing reservoir over a vulnerable spot. Building codes recognize this, which is why low-slope roofs are expected to drain rather than hold water.

The Ontario Building Code addresses roof drainage and the need to move water off the roof; the province publishes the current requirements through Ontario’s building code resources. A roof framed dead level will pond somewhere, so the slope has to come from either the structure or the insulation. Tapered insulation is how you add it without re-framing the building.

Ponding is also the root cause behind a lot of other roof complaints, from blisters to premature membrane failure. If your roof already holds water and you want the full range of fixes rather than just the insulation angle, our guide on moving water off a low-slope roof faster walks through drains, scuppers, and slope together.

How a tapered system is designed

A tapered layout starts at the drains and works outward. The low points sit at the drains, and the insulation thickens as it moves away from them, creating valleys that funnel water in. Between two drains, designers add tapered saddles, often called crickets, so water is pushed sideways into the nearest valley instead of stalling in the middle.

Two numbers drive the design: the slope, expressed as a rise per foot of run, and the distance water has to travel to reach a drain. A longer run needs either a steeper slope or more drains. Get it right and every square foot of the roof has a downhill path to a drain. Get it wrong and you simply move the puddle somewhere else.

The two jobs it does at once

This is where tapered insulation earns its keep. It solves drainage and it adds thermal performance in the same layer, which is a rare two-for-one in roofing.

Because the same boards that create the slope also insulate, a tapered re-roof can lift a building’s roof insulation value at the same time it fixes the puddles. On an older building with thin or wet insulation, that thermal upgrade is a real bonus rather than an afterthought.

When tapered insulation makes sense

It is not the answer for every roof, but it fits a clear set of situations:

• Chronic ponding on a level deck. If the roof was framed flat and holds water, tapered insulation adds the slope the structure never had.
• A full re-roof or re-cover. When the membrane is coming off anyway, it is the natural moment to build in slope and upgrade insulation in one step.
• Drains in awkward spots. Crickets and saddles can route water to drains that the original flat roof left stranded.
• An insulation upgrade is overdue. If the existing insulation is thin or moisture-damaged, replacing it with a tapered system solves two problems at once.

Where a roof already has good slope and drains well, you would not add it. The design call comes down to where the water sits today and what the roof needs over the next twenty years. That is the kind of assessment a commercial roofer does before recommending one approach over another.

Frequently asked questions

Is tapered insulation the same as fixing flat roof drainage?

It is one important tool, not the whole job. Drainage on a low-slope roof depends on slope, the number and placement of drains and scuppers, and keeping those outlets clear. Tapered insulation addresses the slope part by building a gentle grade into the roof so water moves toward the drains. On many roofs that is the missing piece, but if drains are blocked or badly placed, slope alone will not solve it. A good design looks at slope and drains together rather than treating them as separate problems.

Does tapered insulation make the roof much taller?

It adds height only at the high points, and usually less than people expect. Because the boards are thinnest at the drains and thicken with distance, the average added height across the roof is modest, and the low points barely change. Designers also choose the slope and drain layout partly to keep the maximum thickness reasonable, especially where the roof meets walls, parapets, and door thresholds. On most commercial buildings the added height is easily accommodated during a re-roof.

What is tapered insulation usually made of?

Most tapered systems in commercial roofing use polyisocyanurate, a rigid foam board with a strong insulating value for its thickness, although other rigid insulations are used in some assemblies. The boards come in a range of standard slopes plus flat filler panels, so a designer can assemble almost any drainage pattern from stock pieces. The same product also provides the roof’s thermal insulation, which is why a tapered re-roof improves energy performance while it fixes drainage.

Can tapered insulation be added without replacing the whole roof?

Sometimes, but it is most often done as part of a re-roof or re-cover, because the insulation sits beneath the membrane. To install it the membrane has to come off or a new layer has to go over the old assembly, so the work naturally pairs with replacing or recovering the roof. In specific cases a localized tapered section, such as a cricket between drains, can be added during a repair. The right scope depends on the roof’s overall condition, which is what an assessment determines.

The post How Tapered Insulation Works on a Flat Roof appeared first on Industrial Roofing.

Flat roof blisters are the raised bubbles you see pushing up through the surface of a low-slope roof. Each one is a pocket where the membrane has lifted away from the layer beneath it, trapping air or moisture inside. Some sit quietly for years. Others are the first sign of a problem that will open the roof up to water, which is why it pays to know which is which before you decide to act. If a blister has you concerned, the safest first move is to have the roof looked at by a commercial roofer.

The short version: a blister on its own is not an emergency, but it is a symptom. Understanding what formed it tells you whether you are watching a cosmetic quirk or the early stage of a leak.

What a flat roof blister actually is

A flat roof is built in layers: a deck, insulation, and a waterproof membrane bonded on top. A blister forms when two of those layers lose their grip on each other and a void opens between them. Whatever is in that void, air, water vapour, or both, expands when the roof heats up and contracts when it cools. Over many cycles the trapped pocket stretches the membrane upward into the familiar dome.

The key detail is where the separation sits. A blister between plies inside the membrane behaves very differently from one sitting between the membrane and the insulation below it. The deeper the separation, the more of the roof system it can affect, and the more attention it deserves.

Main causes of blistering

Blisters rarely have a single cause. Most trace back to one of these, and often a combination:

• Trapped moisture. Water that got into the assembly during installation, through a leak, or as vapour from inside the building turns to vapour pressure when the sun heats the roof, and that pressure lifts the membrane.
• Poor adhesion. If a layer was bonded over a dusty, damp, or cold surface, the bond is weak from day one. Heat cycling then finishes the job of pulling it apart.
• Solvent or air left in the assembly. On built-up and modified bitumen roofs, gaps in the bitumen or pockets of air between plies become blisters once the roof starts to breathe with the temperature.
• Heat and sun cycling. Even a sound roof expands and contracts daily. A small weak spot becomes a blister over years of that movement, which is why older roofs show more of them.

Because moisture is so often involved, blistering tends to cluster where water collects or where the original installation was rushed. The Canadian Roofing Contractors Association publishes guidance on low-slope membrane performance through its national roofing standards and resources, and the recurring theme is that surface prep and dry conditions during install prevent most of these problems.

When a blister is serious

Here is the line that matters. A blister that is intact, dry, and stable is usually monitored rather than rushed into repair. A blister that has ruptured, sits in a pond of water, or is spreading is a different story, because the membrane is no longer doing its one job.

Watch for a few warning signs: a blister that has worn through at the top, has soft or spongy areas around it, shows staining on the ceiling below, or is sitting on a membrane seam threatening to split. Any of those means water is either getting in already or about to. A single small dome in the middle of an otherwise sound field is far less urgent than a ruptured one next to a drain.

Catching the difference is exactly what a trained eye is for. A close look across the whole roof, not just the obvious blister, is the only way to know whether the rest of the field is sound.

What to do about a blistered roof

Your response depends on what the blister is telling you, and a qualified roofer is the one to make that call. In broad strokes:

1. Leave intact blisters alone. If it is sealed and dry, the membrane is still keeping water out. Note where it is and keep an eye on it.
2. Document changes. Photograph blisters and their locations so you can tell whether they are spreading between visits. Pattern matters more than any single bubble.
3. Act on ruptured or wet blisters. These get cut out and patched, or in a cluster, the section gets rebuilt. The goal is to restore an unbroken waterproof layer.
4. Address the cause, not just the dome. If trapped moisture or standing water is feeding the blistering, fixing drainage and ventilation is what stops new ones from forming.

Standing water deserves special mention, because a roof that drains poorly will keep producing blisters no matter how many you patch. If your roof holds water 48 hours after a rain, that underlying slope problem is worth solving first, and our guide on getting water off a low-slope roof faster explains the options. Where the slope itself is the issue, our team often builds the correct fall back into the roof during a re-cover.

Frequently asked questions

Are flat roof blisters always a sign of a leak?

No. Many blisters are sealed pockets of trapped air or vapour that have not broken through the membrane, so the roof is still keeping water out. The concern is what happens over time, because every blister is a weak point that heat and foot traffic can eventually rupture. An intact, dry blister is usually monitored, while one that has split open or sits in standing water needs attention. The only reliable way to tell which you have is a proper look at the whole roof, not just the bubble.

Can I just pop or cut a blister myself?

It is strongly discouraged. Cutting a blister turns a sealed void into an open wound in your waterproof layer and invites water straight into the assembly, often making a minor issue into an active leak. Blisters also tend to be a symptom of a deeper cause like trapped moisture or poor adhesion, so removing the dome without addressing that cause solves nothing. Proper repair means cutting out the affected area and rebuilding the membrane so it is continuous again, which is work for a commercial roofer.

Why do blisters appear more on older roofs?

Every flat roof expands in the heat and contracts as it cools, and that daily movement works on any weak bond in the assembly. On a new, well-installed roof those weak spots are rare. On an older roof, years of thermal cycling have had time to find every marginal bond, every pocket of trapped air, and every spot where moisture worked in. The result is more blisters as a roof ages, which is one reason regular inspection becomes more valuable the older a roof gets.

Will fixing drainage stop blisters from coming back?

Often, yes, when standing water is the driver. Water that ponds on a roof keeps feeding moisture into the assembly and into vapour pressure under the membrane, so blisters return no matter how many you patch. Correcting the slope so the roof sheds water, whether by improving the existing drainage or building in proper fall, removes that source. It will not undo damage that is already there, but it stops the cycle that creates new blisters and protects the repairs you do make.

The post What Causes Blisters on a Flat Roof? appeared first on Industrial Roofing.

Most commercial roof problems are visible before they become expensive. The trouble is that most property managers don’t know what they’re looking at when they’re up there, so small deficiencies compound quietly until someone calls about water coming through a ceiling tile.

This checklist gives you a structured way to walk a commercial flat roof and document what you find. You need good eyes, a phone camera, and the discipline to do it twice a year.

If you prefer to have a professional handle inspections, our professional flat roof assessment team can provide a written condition report with repair priorities and estimated remaining life, which most institutional landlords and property insurers now expect.

Before you go up: safety and access requirements

Ontario requires fall protection when working within 2 metres of an unprotected roof edge. If your building has guardrails or a permanent fall arrest anchor system installed, confirm they’re rated and in good condition before putting weight on them.

If your rooftop does not have compliant edge protection, you should not be up there without a proper harness and an anchor point rated for the activity. Our rooftop safety system installation team installs permanent guardrail and anchor systems that make routine roof access safe and code-compliant.

At minimum before any roof walk: check weather (don’t walk a wet membrane), tell someone you’re going up, wear soft-soled shoes, and bring your phone for documentation.

Membrane surface inspection

Walk the full surface area in a grid pattern rather than wandering. You’ll miss things if you don’t systematically cover the roof.

Blistering. A small blister under 6 inches in diameter that feels firm is usually a cosmetic concern. A large blister or one that feels soft and spongy when you press it means there’s moisture or air trapped in the assembly beneath. Mark it for professional evaluation.

Cracks and splits. Any visible crack in the membrane surface is a potential water entry point. Particularly watch the perimeter area within 2 feet of parapet walls, where thermal movement stress concentrates.

Open or lifted seams. Run your hand along seams. On TPO and PVC, seams should be solid and fused. Any seam you can get a fingernail under is a problem.

Granule loss on modified bitumen. Patchy areas where the granule surface has worn off expose the underlying asphalt to UV. Widespread granule loss is a sign of accelerated aging.

Surface debris and ponding water. Standing water 48 or more hours after rain is a drainage problem. Check if drains are clogged. Debris mounds trap moisture against the membrane.

Drainage system check

Every drain, scupper, and overflow drain on the roof needs to be clear.

Roof drains: remove the strainer and check the drain body for debris. Pour a bucket of water slowly and confirm it drains at a reasonable rate rather than backing up.

Scuppers: look through them from the roof side. Any bird nesting material, leaves, or debris blocking a scupper is a potential ponding problem during heavy rain. Ontario had several significant late-summer rain events in 2024 and 2025 where blocked scuppers caused interior flooding that proper drainage would have prevented.

Overflow drains: these emergency relief drains are set higher than primary drains. If they show signs of consistent flow (rust staining, debris rings), your primary drains aren’t doing their job.

Flashings and terminations

Flashings are the strips of material that transition from the membrane surface up and over any vertical element: parapet walls, expansion joints, curbs. They’re the most common failure point on commercial roofs.

Base flashings. At every parapet wall, the membrane should turn up the wall face a minimum of 8 inches. The termination bar at the top should be firmly anchored, with sealant at the top edge intact. If the sealant is cracked or the termination bar is pulling away, water can get behind the flashing.

Expansion joints. These should have a continuous flexible bellows or cover above them. Any cracking or splitting in an expansion joint cover needs professional repair because the joint is designed to move, and a rigid repair won’t last.

Penetrations and equipment curbs

Every penetration through the membrane is a potential failure point. On older commercial buildings, penetrations accumulate over years of tenant improvements and HVAC upgrades, sometimes with no formal flashing at all.

For each penetration, check is there a proper curb? Is the flashing continuous and in contact with the curb sides? Is sealant at the top of the curb flashing intact and not cracked? For conduit, is the entry point sealed?

Pay particular attention to areas where multiple penetrations cluster together, typically around HVAC units. Crowded penetration areas are hard to flash properly and often have overlapping repair history that creates complex water paths.

Rooftop equipment condition

You’re not doing an HVAC inspection. But the condition of rooftop equipment affects your roof.

Condensate discharge: HVAC condensate should discharge through a proper line to a drain. If condensate is draining directly onto the membrane, it concentrates water in one spot and can contain refrigerant oil that degrades some membrane types over time.

Unit mounting: check that equipment legs are sitting on proper curbs or isolation pads, not directly on the membrane. Equipment resting directly on the membrane creates abrasion and puncture risk during servicing.

Parapet walls and coping

Parapet walls are the short walls around the perimeter of most commercial flat roofs. They take significant weather exposure and are a common source of leaks that appear to come from the roof but actually enter through the wall.

Coping: the metal cap on top of the parapet should be continuously seamed with no open joints. Water that enters through a coping joint runs down inside the wall cavity and can exit at ceiling level inside the building, nowhere near the roof perimeter. Property managers frequently assume the roof is leaking when the actual failure is coping.

Mortar joints: on masonry parapet walls, check mortar joints for deterioration. Spalling brick or eroded mortar is a water infiltration path that has nothing to do with the roof membrane.

Documentation: what to photograph and record

After every roof walk, document what you found. A photo log that goes nowhere is useless. For each deficiency, take a wide-angle photo showing location relative to a fixed reference, take a close-up of the defect, and write a brief description of what it is and approximate size.

Keep this documentation in a folder per building, organized by inspection date. When you’re negotiating a capital repair budget or making a warranty claim with the membrane manufacturer, this record is what gets decisions made quickly.

When to call a professional

Do the semi-annual walk yourself. Call a professional when you find a blister larger than 12 inches, there is standing water that hasn’t drained within 48 hours of the last rain, a seam has opened, you find any deficiency you can’t clearly categorize, the roof is over 15 years old without a recent condition assessment, or you’re buying, selling, or refinancing the building.

A professional flat roof inspection includes non-destructive testing, documented condition ratings, and repair prioritization. If you suspect wet insulation, add infrared scanning to the scope. An infrared scan after a clear day will show thermal anomalies where wet insulation retains heat differently from dry areas.

Printable commercial roof inspection checklist Download PDF

The post Commercial roof inspection checklist: what property managers should look for appeared first on Industrial Roofing.

1. Why roofing material is the single biggest lifespan factor
2. Commercial flat roof lifespan by material type
3. What shortens or extends your roof life
4. Repair vs replace calculator
5. How to find out what type of roof you have
6. Signs your roof is nearing end of life
7. FAQ

Knowing how long your commercial roof will last sounds like a simple question. The honest answer depends almost entirely on what it’s made of, how it was installed, and how consistently it gets maintained.

Most property managers in the GTA are working with roofs installed by the previous building owner, sometimes 15 or 20 years ago. They don’t always know the membrane type, let alone the installation date. This guide will help you identify what you have, what to expect from it, and when replacement starts making more financial sense than continued patching.

If you’ve been dealing with recurring leaks or drainage issues, our team has been fixing flat roofs for years and can help you figure out what’s worth fixing and what isn’t.

Why Roofing Material is the Single Biggest Lifespan Factor

A flat roof isn’t one thing. It’s a system, and the membrane at the top of that system is what determines whether you get 15 years out of it or 30. Everything else, installation quality, drainage design, deck condition, maintenance frequency, operates within the ceiling set by the membrane choice.

Ontario’s climate is genuinely brutal on commercial roofs. You get freeze-thaw cycles from October through April, UV radiation in summer, and ponding water events that stress seams and flashings every spring. A membrane that handles one of these factors poorly will fail early, full stop.

The good news is all of the major membrane systems used in Ontario can hit their rated lifespan when installed correctly and maintained. Most early failures come from installation shortcuts or deferred maintenance, not inherent material flaws.

Commercial Flat Roof Lifespan by Material Type

Here’s what the data looks like across the main systems you’ll find on commercial and industrial buildings in southern Ontario.

TPO (thermoplastic polyolefin)

Rated lifespan: 15 to 20 years. Real-world average: 20 years with good maintenance.

TPO has become the dominant single-ply membrane in Ontario commercial construction over the past decade. It’s heat-welded, which means seams fuse together into a continuous waterproof layer rather than relying on adhesive or tape. That’s a significant advantage over older systems.

The variability in lifespan comes down to two things: membrane thickness and seam quality. A 45-mil TPO installed at minimum spec will age out faster than an 80-mil membrane with wide, properly welded seams. On industrial roofs, 60-mil or heavier is strongly recommended. Cheap installation is the main reason TPO roofs fail early.

EPDM (ethylene propylene diene monomer)

Rated lifespan: 20 to 25 years. Real-world average: 20 to 25 years.

EPDM is the older rubber membrane that built up the single-ply market in Ontario before TPO took over. It’s still widely used on re-covers and where chemical exposure is a concern. Some industrial rooftops have exhaust or runoff that degrades TPO faster than EPDM. Any EPDM roof over 15 years old is worth a seam inspection.

PVC (polyvinyl chloride)

Rated lifespan: 20 to 25 years. Real-world average: 25 years.

PVC performs similarly to TPO in most Ontario climates, with one specific advantage: chemical resistance. Restaurant chains and food processing facilities in the GTA use PVC heavily for this reason. After year 20, any rooftop work should be done carefully to avoid cracking an aged PVC membrane.

Modified bitumen (mod bit)

Rated lifespan: 15 to 25 years. Real-world average: 18 to 22 years.

Modified bitumen is still very common on Ontario industrial and commercial buildings built before 2005. A well-installed mod bit roof is genuinely tough. Multi-ply systems resist puncture better than single-ply membranes, which matters on roofs with heavy foot traffic for HVAC maintenance.

Built-up roofing (BUR)

Rated lifespan: 15 to 30 years (highly variable). Real-world average: 25-30 years under good conditions.

Built-up roofing, also known as ‘tar and gravel’, is the oldest commercial flat roofing system still in service in Ontario. BUR systems can last a very long time when the gravel surface protects the underlying felts from UV exposure.

What Shortens a Flat Roof’s Life

Membrane type sets the ceiling. What happens above and below that ceiling is largely within a property manager’s control.

Deferred maintenance is the single biggest accelerator of roof failure. A small blister that costs less to fix becomes a full flashing failure that costs a lot more to repair if it sits through two more winter cycles. Ontario buildings with annual or semi-annual inspection schedules consistently outlast those with reactive maintenance programs by 5 to 8 years on the same membrane system.

Ponding water is the second major factor. Flat roofs aren’t actually flat; they’re designed with slope to drain. When drains clog or the deck deflects and holds water, that water works on the membrane continuously. Even a small pond sitting for 48 hours after a rain event accelerates membrane degradation at the contact point.

Unauthorized penetrations are a silent killer. Every time an HVAC, electrical, or telecom contractor cuts into or anchors through a membrane without proper flashing protocol, they create a potential leak point.

A formal roof maintenance program reliably adds years. Flat roof maintenance contracts cover drain clearing, flashing checks, membrane surface inspection, and documentation of any deficiencies. That documentation also gives you leverage when negotiating manufacturer warranty claims.

How to Find out What Type of Roof you Have

TPO is white or light grey with a smooth, slightly plasticky surface. Seams are welded and slightly raised. EPDM is black and feels like thick rubber. PVC looks similar to TPO but tends to be slightly shinier. Modified bitumen has a granulated surface on the cap sheet, similar to shingle granules.

When in doubt, a flat roof inspection will document the membrane type, condition rating, and estimated remaining life. A flat roof infrared scan adds another layer, it identifies wet insulation beneath the surface that cannot be seen in a visual inspection.

Signs your Commercial Roof is Nearing end of Life

These are the signals that shift the calculation from repair to replace.

Blistering is widespread. Small, isolated blisters are repairable. When blistering covers 20% or more of the field membrane, the underlying insulation is almost certainly compromised.

Seam failures are recurring. One seam failure is a repair. Recurring seam failures across multiple areas means the membrane has aged past the point where individual repairs hold.

You’ve had three or more leak events in one year. A roof generating three or more calls per season is consuming maintenance budget that would be better applied to replacement.

The system is past 85% of rated lifespan. Once you cross that threshold, capital reserve planning should start. Lead time for scoping, tendering, and scheduling a major commercial roof project can run 6 to 12 months.

Commercial flat roof lifespan quick guide Download PDF

The post How long does a commercial flat roof last? A lifespan guide by material appeared first on Industrial Roofing.

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, roofing commercial and industrial buildings in Ontario since 1973, 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.

For us, commercial flat roofing isn’t just about installing materials – it’s about doing the job properly, safely, and to a standard that we’d be confident putting our name behind every single time.

That’s why we’ve made it a priority to align ourselves with leading industry organizations and follow strict safety practices on every project we take on.

Members of the Canadian Roofing Contractors Association

We are proud members of the Canadian Roofing Contractors Association (CRCA), one of the leading organizations representing roofing professionals across Canada.

For us, this isn’t just a badge, it’s a way of staying connected to the wider industry and making sure we’re always working in line with the latest standards, materials, and best practices.

Being part of CRCA means we stay aligned with:

• National roofing standards and best practices
• Ongoing industry developments and innovations
• Professional guidelines that ensure consistent quality across every project

It also reflects our commitment to operating as a trusted, reputable commercial roofing contractor within the Canadian industry.

Members of the Ontario Industrial Roofing Contractors Association

We are also members of the Ontario Industrial Roofing Contractors Association (OIRCA), which focuses specifically on commercial and industrial roofing across Ontario.

Through OIRCA, we maintain:

• Up-to-date knowledge of Ontario-specific roofing standards
• Compliance with provincial regulations and safety requirements
• Access to ongoing training and industry resources

This ensures that every project we complete meets not only national standards, but also the specific demands of Ontario’s commercial roofing environment.

Fully Registered With Workplace Safety and Insurance Board (WSIB)

Safety on site is a top priority for our team.

We are fully registered with the Workplace Safety and Insurance Board (WSIB), which means:

• Our team is covered under Ontario’s workplace insurance program
• We meet strict safety and compliance requirements
• Our clients have peace of mind knowing they are working with a responsible contractor

Why It Matters for You

All of this isn’t just about memberships, it’s about how we actually work on site.

When you choose Industrial Roofing Services Limited, you can expect:

• Careful planning before any work begins
• Proper safety systems and equipment on every project
• A team that’s trained, experienced, and accountable
• Clear communication from start to finish

We know that hiring a commercial roofing contractor is a big decision. You’re trusting someone to work on your building, protect your investment, and make sure everything is done properly.

By working with a company that’s aligned with recognized industry organizations and safety standards, you’re reducing risk and gaining confidence that the job will be handled professionally from day one.

Let’s Talk About Your Roof

Whether you need an inspection, repairs, or a full replacement, our team is ready to support you.

Get in touch with Industrial Roofing Services Limited today to schedule a consultation.

The post Our Commitment to Industry Standards & Safety: Trusted Roofers in Ontario appeared first on Industrial Roofing.

The quickest way to tell is by looking at the surface:

• Gravel embedded in the top layer? Likely a Built-Up Roof (BUR).
• Dark, smooth rolled asphalt sheets with visible seams? Probably Modified Bitumen.
• Black rubber membrane? Typically EPDM.
• White membrane with heat-welded seams? Likely TPO or PVC.
• Visible metal panels? A metal roofing system.

Each flat roofing material has specific visual clues. The only way to know for certain, however, is through a professional roof inspection where we examine the membrane, seams, flashings, insulation, and overall system.

Let’s walk through how to identify the most common flat roofing materials in Ontario, and why it matters.

Table Of Contents:
Why Is It Important?
Types Of Flat Roof Systems
Asphalt Flat Roofs
Single Ply Roofs
Metal Roofs
Still Unsure?

Why Is It Important To Know What Type Of Material Your Roof Is Made From?

Knowing your roof system isn’t just a technical detail, it directly affects:

• How repairs are performed
• What maintenance schedule you should follow
• What type of replacement system is compatible
• Warranty coverage
• Expected lifespan
• Energy performance
• How your roof handles Ontario’s freeze-thaw cycles

For example, repairing a PVC membrane is completely different from repairing a built-up asphalt roof. Using the wrong method can shorten your roof’s life or void warranties.

When we visit a site, identifying the system is always our first step before recommending any solution.

Types Of Flat Roof Systems & How To Know Which One You Have

Flat roofs in Ontario typically fall into three main categories:

1. Asphalt-based systems (BUR and Modified Bitumen)
2. Single-ply membrane systems (EPDM, TPO, PVC)
3. Metal roofing systems

Each has distinct characteristics.

Let’s break them down.

Asphalt Flat Roofs

Asphalt systems are among the oldest and most trusted flat roofing materials. They are built in layers and are typically darker in appearance.

You’ll usually find these on older commercial and industrial buildings throughout Ontario.

1. BUR Roof (Built-Up Roofing)

Often called a “tar and gravel” roof.

Tell-Tale Characteristics Of BUR

• Gravel or small stones embedded on the surface
• Thick, layered appearance
• Dark asphalt beneath the aggregate
• Feels solid and heavy underfoot
• Often found on older buildings (20+ years old)

If you see loose gravel across your roof, chances are it’s a BUR system.

Repairs, Maintenance & Lifespan of BUR

BUR systems are durable because they are built with multiple plies (layers) of asphalt and reinforcing fabric.

• Lifespan: 20–30+ years with proper maintenance
• Repairs typically involve patching layers and resealing affected areas
• Gravel may need redistribution over time
• Drainage must be monitored carefully

In Ontario’s climate, ponding water and freeze-thaw cycles can stress older BUR systems.

When Is BUR Recommended

• Large commercial or industrial buildings
• Roofs with moderate foot traffic
• Owners looking for a proven, heavy-duty system

While newer membrane systems are more common today, BUR still performs reliably when properly maintained.

2. Mod-Bit Roofs (Modified Bitumen)

Modified Bitumen roofing is essentially an evolution of BUR, but more flexible and modern.

Tell-Tale Characteristics Of Mod-Bit

• Smooth or slightly granulated surface
• Rolled sheet appearance
• Visible seams between membrane rolls
• Torch-applied or self-adhered installation marks
• Usually black or dark grey

Unlike BUR, it doesn’t typically have loose gravel. It looks more uniform.

Repairs, Maintenance & Lifespan of Mod-Bit

Modified Bitumen systems are reinforced with polymers (SBS or APP) to improve flexibility.

• Lifespan: Around 20 years
• Repairs are typically torch-applied patches
• Seams and flashing areas require regular inspection
• Performs well in Ontario’s temperature swings due to flexibility

We often see these on mid-aged commercial buildings across the GTA.

When is Mod-Bit Recommended

• Buildings exposed to temperature fluctuations
• Roofs requiring flexibility
• Projects where durability and repairability are priorities

Single Ply Roofs

Single-ply systems are installed in large sheets and have fewer layers than asphalt systems.

They are lightweight, efficient, and very common in modern commercial construction.

1. EPDM Roof

A synthetic rubber membrane.

Tell-Tale Characteristics Of EPDM

• Black rubber appearance (sometimes white)
• Feels flexible and slightly elastic
• Seams are glued or taped
• Smooth, uniform surface

If your roof looks like a giant sheet of rubber, it’s likely EPDM.

Repairs, Maintenance & Lifespan of EPDM

EPDM roofing is known for durability and flexibility.

• Lifespan: 25-40+ years with proper care
• Repairs involve seam resealing or rubber patches
• Annual inspections recommended
• Handles freeze-thaw cycles well

EPDM is one of the most common systems we see across Ontario.

When Is EPDM Recommended

• Large commercial flat roofs
• Owners looking for long-term cost efficiency
• Roofs exposed to harsh weather

1. TPO Roof

A white thermoplastic membrane.

Tell-Tale Characteristics Of TPO

• White or light-coloured membrane
• Heat-welded seams (look like clean fused lines)
• Smooth, reflective surface
• Lightweight feel

If your roof is bright white and reflective, it’s likely TPO.

Repairs, Maintenance & Lifespan of TPO

TPO seams are heat-welded, which creates strong waterproof joints.

• Lifespan: 15-20 years
• Seam integrity is key
• Punctures are patched using heat-welded materials
• Reflectivity improves energy efficiency

TPO roofing is common on newer commercial builds.

When Is TPO Recommended

• Buildings looking for improved energy performance
• Large open roof areas
• Modern commercial construction

1. PVC Roof

Another white single-ply membrane, but more chemically resistant.

Tell-Tale Characteristics Of PVC

• White or light-coloured membrane
• Heat-welded seams (similar to TPO)
• Typically installed on restaurants or industrial buildings
• Often slightly more rigid than TPO

PVC roofing can look very similar to TPO, professional inspection is usually required to confirm.

Repairs, Maintenance & Lifespan of PVC

• Lifespan: 15–25 years
• Highly resistant to grease and chemicals
• Seam welding is critical
• Regular drainage checks prevent stress

When Is PVC Recommended

• Buildings exposed to oils, chemicals, or restaurant exhaust
• Industrial applications
• Owners prioritizing durability and fire resistance

Metal Roofs

While not a membrane system, metal is still used on some low-slope or flat-style roofs.

Tell-Tale Characteristics Of Metal Roofs

• Visible metal panels
• Raised seams or fasteners
• Can show signs of rust over time
• No membrane surface

Metal roofs are easier to identify because they are visibly metal.

Repairs, Maintenance & Lifespan of Metal Roofs

• Lifespan: 30-50+ years, depending on coating
• Repairs involve panel replacement or sealing fasteners
• Rust prevention is critical
• Expansion and contraction must be managed

When Is Metal Roofs Recommended

• Buildings seeking long-term durability
• Low-slope applications
• Industrial facilities

Still Not Sure What Your Roof Is Made Of?

Even with these visual clues, some systems look very similar, especially TPO and PVC, or older Mod-Bit and BUR systems.

The safest and most accurate way to identify your roof system is through a professional inspection.

When we visit a site at Industrial Roofing Services Limited, we:

• Examine the membrane type
• Check seam construction
• Review insulation layers
• Assess flashing details
• Identify drainage design
• Determine remaining lifespan

From there, we can explain exactly what you have, and what that means for repairs, maintenance, and long-term planning.

If you’re unsure what your flat roof is made of, book an inspection and let us walk the roof with you. We’ll identify the system and explain it clearly, just like we’ve done here.

The post How Do I Know What My Flat Roof Is Made Of? appeared first on Industrial Roofing.

Whether you manage an industrial facility, office building, retail plaza, warehouse, or multi-residential property, understanding when snow becomes a problem – and how it should be addressed – is critical to protecting your roof and your building

Table Of Contents:
24/7 Snow Removals for Flat Roofs
Do You Always Need to Remove Snow from a Flat Roof?
Warning Signs Of Excessive Snow Build-Up
How To Remove Snow From Flat Roofs
Why Choose a Professional Roofer for Snow Removal?
What Does “Flat Roof Snow Load” Mean?
How Much Does Snow Weigh?
How Often Do Roofs Collapse from Snow Weight?
How To Plan for Winter Roof Safety

Quick Answer: Do Commercial Flat Roofs Need Snow Removal?

Yes- but only when conditions warrant it, and only by professionals.

A well-designed and properly maintained flat roof can safely support snow up to its engineered load capacity. However, snow should be professionally removed when accumulation becomes excessive, uneven, wet, or begins to interfere with drainage, rooftop systems, or structural performance.

Snow removal should never be handled by property staff or general snow contractors, it requires commercial roofing expertise and safety compliance.

24/7 Snow Removals for Flat Roofs

At Industrial Roofing Services Limited, we provide professional commercial roof snow removal services throughout Toronto, the GTA, and Southern Ontario – including 24/7 emergency flat roof repairs during severe winter conditions.

Our approach is not about clearing every inch of snow. It’s about strategic, controlled removal that:

• Reduces the risk of structural stress and overloading from excessive snow accumulation
• Protects roofing membranes and flashing
• Supports proper roof drainage by keeping scuppers and drains clear
• Reduces the risk of leaks and helps prevent water overload
• Focuses on removals around HVAC units, drains, and vents, lowering the chance of snow being drawn into equipment, which can lead to interior leaks or system damage

Proactive removal can extend the lifespan of the roof membrane by minimizing ice damming and freeze-thaw damage. We work across all major commercial flat roofing systems, including TPO, PVC, EPDM, Modified Bitumen, and Built-Up Roofing, and we coordinate with structural engineers when snow load thresholds are a concern.

Do You Always Need to Remove Snow from a Flat Roof?

No, not always. But in heavy and continued snowfalls, being proactive with your roof snow removal can save you from issues later down the line.

Flat roofs are designed to carry snow loads defined by the National Building Code of Canada (NBCC). Small amounts of dry, evenly distributed snow may not pose a risk.

However, professional snow removal is recommended when:

• Heavy and continued snowfall
• Snow becomes wet, compacted, or unevenly drifted
• Roof drains or scuppers are blocked or frozen
• Standing water forms beneath snow cover
• Freeze-thaw cycles increase ice formation
• Additional heavy snowfall is forecasted
• Structural load limits may be approached

Snow removal should never be attempted by property managers, maintenance staff, or tenants. Improper removal techniques can damage roofing membranes and increase structural risk.

Warning Signs of Excessive Snow Build-Up on Commercial Flat Roofs

After heavy snowfall or repeated freeze-thaw cycles, snow-related roof problems don’t always show up right away. In many cases, the impacts of snow and ice first show inside the building or around its exterior, not on the roof itself. The warning signs below can help you spot potential issues early – without needing to step onto the roof.

1. Water Sitting on the Roof After Snow Starts Melting

When the snow melts, the water should drain away fairly quickly. If it doesn’t, that water can sit on the roof and slowly work its way into weak spots.

What you might notice:

• Water dripping from the ceiling or light fixtures on upper floors
• Ceiling tiles that look darker, soft, or swollen
• Leaks that only appear during the day when temperatures rise
• Ongoing moisture issues after snowstorms

This is often a sign that snow or ice is blocking the roof’s drainage points.

2. Water Not Draining Away From the Building

When the snow melts, you should see water flowing away from the building through downspouts (the vertical pipes attached to the outside of the building).

What you might notice:

• No water is coming out of the downspouts during melting
• Large icicles are forming where downspouts exit the building
• Ice or water stains running down the outside of the building
• Puddles are forming close to the building instead of water flowing away

These signs suggest water is trapped above and can’t drain properly.

3. Ceilings That Look Lower, Uneven, or Bowed

Heavy snow can place extra weight on the roof structure. In some cases, that stress shows up inside the building before it’s visible anywhere else.

What you might notice:

• Ceiling tiles that suddenly look uneven
• Light fixtures or sprinkler heads sitting lower than normal
• Sections of the ceiling that look slightly curved or dipped
• Changes that weren’t there before the snow

Even small changes can be an early warning sign and shouldn’t be ignored.

4. New or Unusual Noises After Heavy Snow

Buildings naturally make some noise, but heavy snow can introduce new sounds caused by materials shifting under extra weight.

What you might notice:

• Creaking, cracking, or popping sounds
• Noises coming from the ceiling or roof area
• Sounds that happen at night or when temperatures change
• Reports of unusual noises from tenants or staff

These noises can be a sign that the structure is under stress.

5. Water Stains, Drips, or Damp Smells Indoors

Snow doesn’t have to fully melt to cause leaks. Even small amounts of moisture can enter through seams or flashings under snow cover.

What you might notice:

• Brown or yellow stains on ceilings or walls
• Active dripping after snow or ice begins to melt
• Damp or musty smells near the top floor
• Wet ceiling tiles or insulation in mechanical rooms

These are often the earliest visible signs of a snow-related roof issue.

6. Doors or Windows Suddenly Hard to Open or Close

In some cases, excess roof weight can cause slight shifts in the building structure.

What you might notice:

• Doors that start sticking or rubbing
• Windows that no longer close smoothly
• Small cracks forming near door or window frames
• Changes that appeared after heavy snowfall

While this doesn’t always mean a roof problem, it can be related to structural stress.

7. Snow Piled Higher in Certain Areas of the Roof

Wind can push snow into certain parts of the roof, causing uneven build-up.

What you might notice (from safe locations only):

• Snow is visibly piled higher near the rooftop equipment
• Snow collecting along the roof edges or walls
• Large icicles are forming below those areas
• The same spots are causing issues every winter

These areas often carry much more weight than the rest of the roof.

What Not to Do

Do not access the roof without professional clearance
Do not attempt to shovel or chip ice yourself
Do not allow general snow removal contractors onto the roof
Do not ignore small leaks or assume they will resolve on their own

How To Remove Snow From Flat Roofs

Commercial snow removal is a controlled roofing operation – not general snow clearing. Here’s what property managers should expect when working with professionals:

1. Pre-Removal Assessment

Before any snow is touched, we take time to understand the roof itself. The roofing contractor reviews roof plans, identifies drainage locations, rooftop equipment, and known weak points.

If there is any concern that the snow load could be approaching structural limits, a structural engineer may be consulted before removal begins. This ensures snow is removed in a way that relieves stress rather than shifting it to another part of the roof.

2. Safety Planning

The crew establishes safe access points to the roof and sets up fall protection systems in accordance with Ontario Working at Heights requirements. Safe locations for snow disposal are identified in advance so that snow can be moved off the roof without creating hazards at ground level.

3. Priority Snow Relief

Snow is not removed all at once or evenly across the roof. Instead, professionals focus first on areas that pose the greatest risk.

These typically include:

• Roof drains and drainage paths, so that melting snow can escape
• Areas where wind has caused deeper snow buildup
• Around rooftop equipment, where snow can trap water or add extra weight
• Low spots in the roof where water and snow naturally collect

By relieving pressure in these areas first, the overall load on the roof is reduced more safely and effectively.

4. Controlled Snow Removal

Once priority areas are addressed, the remaining snow is removed in a controlled manner. Roofing professionals use tools and techniques designed to protect the roof membrane, avoiding sharp or heavy equipment that could tear or puncture the surface.

Snow is removed gradually and evenly to prevent sudden load shifts. Importantly, snow is never piled or stored on the roof, even temporarily, as this can create new stress points.

5. Ground-Level Snow Management

As snow is removed from the roof, it must be placed somewhere safe at ground level. Our contractors ensure snow is deposited away from:

• Building entrances and exits
• Emergency access routes
• Fire lanes and loading areas
• Pedestrian walkways

On large sites or in dense urban areas, snow may need to be transported off-site to prevent congestion or safety issues around the building.

6. Post-Removal Inspection

Once snow removal is complete, the roof is inspected to confirm that:

• Drainage is functioning properly
• No damage occurred during removal
• Previously hidden issues are identified early

If any vulnerabilities or minor damage are discovered, they can be addressed immediately – helping prevent leaks or emergency repairs later in the winter.

Why Choose a Professional Roofer for Snow Removal?

Snow removal on a commercial flat roof isn’t a routine maintenance task – it’s a specialized roofing service that directly affects the safety, performance, and lifespan of your roof system.

Professional commercial roofers understand that removing snow incorrectly can cause as much damage as leaving it in place. That’s why trained roofing crews follow controlled methods that reduce weight without compromising the roof itself.

Experienced roofing professionals:

• Are Working at Heights certified, ensuring safe access and fall protection
• Understand how snow weight is distributed across a flat roof
• Know how to clear snow without damaging membranes, seams, or flashing
• Use tools and techniques designed specifically for roofing surfaces
• Recognize early warning signs of structural stress or membrane failure
• Carry proper commercial insurance and liability coverage

At Industrial Roofing Services Limited, snow removal is approached as part of a broader roof protection strategy – not a quick clear-off. Roofing commercial and industrial buildings in Ontario since 1973, our team understands how winter conditions impact different roofing systems.

What Does “Flat Roof Snow Load” Mean?

Snow load refers to the temporary (live) weight imposed by snow and ice on a roof structure. Unlike permanent loads, snow load changes constantly due to:

• Snowfall amount and density
• Wind drifting
• Roof geometry
• Building heat loss
• Melting and refreezing

Snow load capacity is defined during building design and documented in construction drawings. When records are unavailable, structural engineers can calculate safe load thresholds.

Importantly, snow does not distribute evenly – drifting often concentrates weight near parapets, rooftop equipment, and transitions.

How Much Does Snow Weigh?

Snow weight varies significantly depending on moisture content:

• Light, dry snow: ~7-10 lbs per cubic foot
• Wet, compacted snow: up to 30 lbs per cubic foot

Rain, partial melting, and refreezing can dramatically increase weight – even when snow depth appears reduced. Ice weighs the same as water, but occupies less space, further increasing load concentration.

Ground snow depth does not reliably indicate rooftop snow load – roof conditions must be assessed directly.

How Often Do Roofs Collapse from Snow Weight?

Complete roof collapse from snow alone is rare, particularly on modern, well-maintained buildings. However, risk increases due to:

• Aging roof systems
• Poor drainage
• Deferred maintenance
• Structural modifications
• Prolonged or extreme winter conditions

More commonly, excessive snow causes structural deflection, which can damage:

• Sprinkler systems
• Mechanical lines
• Electrical conduits
• Interior finishes

These issues can be just as costly – and disruptive – as structural failure.

How To Plan for Winter Roof Safety

Snow removal is most effective when it’s part of a proactive winter roof management strategy, including:

• Pre-winter roof inspections
• Flat Roof drainage maintenance
• Defined snow-removal thresholds
• Emergency response planning

Industrial Roofing Services Limited works with property managers, facility teams, and engineers across Toronto, the GTA, and Southern Ontario to manage winter risks safely and professionally.

If snow accumulation on your commercial flat roof is a concern – or if you want to be prepared before the next storm – our team is ready to help.

Protect your roof. Reduce risk. Stay operational all winter.

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