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We inspect the perimeter and corners first, where the uplift is highest, and you get the condition of your edge in writing, photographs included.
50 years in one trade | ★ 4.8 stars on Google | Fully insured, licensed, WSIB covered | Spring & fall inspection at no cost
Brock Industrial Runs Right Down to the Water
Look at where Pickering put its industry and the roofing problem announces itself.
Brock Industrial Park covers about 869 hectares — some 2,147 acres — and the City describes its boundaries plainly: Sandy Beach Road to the west, Highway 401 to the north, West Duffins Creek to the east, and Lake Ontario to the south. Manufacturing, logistics, warehousing. Ontario Power Generation is in there, alongside Hubbell Canada, Nelson Industrial, Noranco and Signature Aluminum.
Whites Road Prestige Business Park is smaller and tighter at 21 hectares between the 401 and Rosebank. The Pickering Innovation Corridor is the growth story — 324 hectares up along Highway 7 and the 407, with something like 24,000 jobs anticipated, and Seaton beyond it carrying room for up to 35,000 more.
The nuclear station is still very much here too: Units 5 through 8 are operating and being refurbished for another thirty-plus years, whatever you may have read about a shutdown.
But the fact that matters for a roofing crew is the first one. An industrial park whose southern boundary is a Great Lake is an industrial park with very little standing between its buildings and the wind coming off open water.
Who'll be walking your edge
1977 · Brian Sharp founds the company. Commercial flat roofs from day one.
4.8 · Where our Google score sits
Own crews · No subcontractors on any Crown job
May 2024 · Our Pickering job, posted in the gallery
Wind tends to find the one fastener nobody checked, so it matters who's holding the drill. On a Crown job, it's always one of ours. The reviews further down tell you how that's gone for other owners.
Wind Does Not Push a Flat Roof Down. It Pulls It Up, and Not Evenly
Most people picture wind pressing on a building. On a low-slope roof the force that matters is the opposite one — as air accelerates over the parapet it drops in pressure and lifts the membrane from above, while the air inside the building pushes up from below. The membrane is being pulled off, not pressed down.
The critical thing, and the thing that decides where a membrane fails, is that this suction is nothing like uniform.
Roof design treats it as three separate zones, and the loads in them are genuinely different. The field — the wide middle — carries the least. The perimeter carries roughly twice that. The corners carry the most of all, on the order of three times the basic pressure. That is not a rule of thumb somebody invented; it is how wind loads are calculated, and the roofing industry in this country states the same ratio openly. The edge zone itself is never narrower than about two metres, and on a large building it is considerably wider.
Now put that next to how these roofs are usually inspected. Somebody walks the middle, looks at the field, checks the drains, and comes back down. The part carrying three times the load gets a glance from ten metres away.
Here is what that costs. Canadian roofing industry guidance is blunt about it: the majority of roof cover failures in windstorms involve perimeter flashings that were improperly designed or constructed. Post-storm investigation in North America has put the share of roofing system damage originating at the perimeter at close to sixty per cent. And research here at home, instrumenting real edges in the field, reached the same conclusion — that the majority of failures were failures of the metal roof edge.
The mechanism has a name that tells you everything: the zipper effect. Once the edge securement lets go at one point, the membrane has an exposed leading edge for the wind to get under. From then on, progressively less force is needed to peel it back. A membrane that would have survived the storm intact loses a corner in the first gust and then loses the field over the following hour — not because the membrane was weak, but because a length of edge metal was fastened by someone who treated it as trim.
On an exposed site like the Brock lands, with a long open run of water to the south and nothing to slow the air down, that sequence is not theoretical. It is the failure mode we are called out to.
What We Look At, and Why It Isn't the Middle
On an exposed Pickering building our inspection runs the opposite way round from the usual one. We start at the edge and move inward.
What we are looking for is securement rather than appearance. Whether the edge metal is continuously fastened or held by a handful of tired screws. Whether the cleat or bar is still gripping. Whether the membrane is properly terminated behind the metal or simply tucked. Whether fasteners have backed out, corroded, or been overdriven through the deck flange. Whether anyone has re-flashed a section and left a discontinuity — an interruption in a perimeter is exactly where a zipper starts.
Corners get their own attention, because they carry the worst of it and because they are the hardest detail on the building to execute properly. Parapet caps and coping joints matter here too: a coping that lifts takes the termination underneath it with it.
Then we look for what has already happened without anyone noticing. A section of edge metal that has moved and reseated leaves a gap that drives water into the perimeter of the assembly, and that water shows up as wet insulation along the edge long before it shows up as a stain inside. Scanning for water that got in behind it finds that, and it is a good early indicator that the edge has been working loose for several seasons.
None of this takes long. A close look at the perimeter twice a year, spring and fall, is a genuinely small cost against the alternative — and on this stock it is the single highest-value inspection there is.
The Crown Edge-In Inspection
Most inspections start in the middle and lose interest by the parapet. Ours runs the other way.
1. Perimeter and corners first
Edge metal, cleats, terminations, coping joints and fasteners checked for grip along the whole run, not sampled at a couple of spots.
2. Scan behind the metal
An infrared pass along the perimeter picks up water that's got in where the edge has been moving.
3. Photograph it and write it up
A written report with photos of each corner and any break in the edge. Keep it; after a storm it's the record your insurer will want.
4. Choose the job that fits
Leave it and maintain it, re-secure the perimeter and reassess, or tear off and rebuild with a fastening pattern that tightens at the edges and corners, spelled out in the quote.
What Goes Back On an Exposed Roof
When an exposed roof is replaced, two questions matter more than the brand of membrane: how the assembly is held down, and how the perimeter is built.
On attachment, the honest position is that it depends on the building. Mechanically attached assemblies are fastened through to the deck and the fastening pattern is tightened in the perimeter and corner zones precisely because the loads there are higher — which is the right answer on plenty of Pickering warehouses. Adhered assemblies behave differently under uplift and suit other buildings. What should never happen is a field pattern carried uniformly to the edge because it was simpler to fit. A mechanically attached PVC system done properly has a different fastening density at the corner than in the middle of the field, and if a quote you are looking at does not distinguish between those zones, ask why.
On the perimeter: the edge is part of the roof system, not trim that gets added at the end. There are test standards for edge securement precisely because it is a structural component, and specifying it properly costs very little relative to what it protects.
The rest follows what we do everywhere. PVC single-ply on most distribution and manufacturing roofs, material warranties up to twenty years. SBS modified bitumen where the deck is concrete and traffic is heavy, installed by us. Hot-asphalt built-up on the older stock, with our fifteen-year workmanship warranty. We service TPO and EPDM on buildings that already have them but we do not install either. And a full replacement is always a tear-off to the deck, which on a wind-exposed building matters twice over — recovering leaves you fastening a new assembly into an old one whose own attachment nobody has verified.
One more thing worth doing while the assembly is open: photograph the edge detail. It is the cheapest insurance document you will ever produce, and after a storm it is the difference between a claim and an argument.
Repair, Maintenance and Roof Installation on an Exposed Site
Not every exposed building needs a new membrane, and a great deal of what we do in the Brock lands is smaller than that.
A perimeter repair is the commonest job on this stock and it is cheap relative to what it prevents. Re-securing a run of edge metal, replacing corroded or backed-out fasteners, rebuilding a coping joint that has opened, re-terminating the membrane properly behind the metal rather than tucked under it. None of that is a big project and all of it buys years on an exposed elevation.
Flat roof repairs inside the field follow the ordinary rules: find where the water actually got in, cut back to dry insulation, rebuild the detail, photograph it. On a lakeside building there is one extra question we always ask, which is whether the wet area is sitting along a perimeter, because that usually means the edge has been working loose for several seasons and the repair belongs at the edge rather than where the stain is.
Upkeep on an exposed site is worth more than it is anywhere else, and it is mostly about the perimeter. Twice a year, walk the edge, check the securement, clear the drains, photograph the corners, and file it. Two hours of attention, recorded, is the difference between a building that loses a corner in a windstorm and one that does not.
After a storm the sequence matters as well, and it is worth writing down before you need it. Get somebody up for a safety check as soon as it is safe to be up there, photograph anything that has moved, and have the perimeter looked at along its whole length rather than only where the obvious harm is. Debris removal comes next, because a loose sheet of metal on an exposed site is a second problem waiting for the next gust. Then the assessment: is this a flat roof repair, a partial rebuild, or a claim? Our roofing crews will give you that answer in writing the same week, with photographs, which is what an insurer wants and what most contractors do not hand over unprompted. A roofing specialist who has walked your perimeter before the storm can also tell you what changed, which is worth a great deal when somebody is deciding what the weather did and what was already there.
Installation is the other half of what we do, and on this stock the installation detail that matters is the fastening pattern. A correct installation has a denser pattern in the perimeter and denser again in the corners, because that is where the loads are. An installation that carries the field pattern straight out to the edge looks identical from the ground and behaves completely differently in a gale. When you are comparing prices, that is the line to look for.
Some of what we do here is new construction rather than a tear-off, with the Innovation Corridor and Seaton adding buildings every year. We do that installation alongside a general contractor on the same terms: the perimeter gets specified properly, the corners get the pattern they need, and the edge detail gets photographed before anything covers it.
Roofing Services in Pickering, and the Ones We Don't Offer
It is worth being plain about the shape of the business, because the roofing trade in Durham covers everything from a two-van residential outfit to a national broker.
Crown is commercial and industrial only. The roofing services are survey and infrared scanning, perimeter and field repairs, planned maintenance, full tear-off and replacement, and new installation alongside a general contractor. Warehouses, plants, distribution buildings, schools and clinics. Low-slope assemblies, nothing else.
What we do not do is worth reading before you call. We are not a home roofing company — if the building is a house, we are the wrong number and we will tell you who to ring. We do not fit shingles. We do not do siding, eavestrough or downspouts. We do not sell skylight units, although where a building already has one the curb and the weatherproofing around it is ours. We are not a TPO or rubber-membrane installer, though we will service either where a building already carries one. And we do not do roof cleaning or coatings sold as an alternative to fixing something properly.
There are no subcontracted crews on a Crown job. The roofing specialists on your building are our employees, the foreman is ours, and the same crew comes back for the inspections. On an exposed site that continuity matters more than it sounds, because the person who fastened your edge metal is the person who comes back to look at it.
The trade-off is that we are specialists rather than a one-stop trade. If your building needs four different things, we are one of four calls. What you get in exchange is a firm that has spent fifty years on exactly this kind of assembly and that has no reason to talk you into a bigger job, because roofing is the only thing we have to sell.
For most Pickering buildings the honest set of choices comes down to three options: leave it and maintain it, fix the perimeter and reassess, or take it off and start again. We will tell you which one your building is in, and we will put the roofing installation detail in writing either way so you can compare us against anybody else on something more useful than a total.
Before you call: “but nothing's leaking”
Why pay for a look when nothing's leaking?
You won't. Spring and fall visits from us are free. And a dry ceiling only tells you the membrane's working. It says nothing about the fasteners holding your edge down.
We've already got a replacement quote.
Good, send it over. We'll check whether it fastens the corners differently from the field, and you'll get our own itemised number to set beside it.
Our Pickering Flat Roofing Job, and Fifty Years of One Trade
Crown has been doing this since 1977 — commercial and industrial flat roofs, nothing else, with our own crews rather than subcontracted labour. Brian Sharp founded the company. Joe Ferrier is President.
The Pickering job in our gallery closed in May 2024. It sits with the rest of our completed jobs, sorted by city and month, photographed up there by the people who did it.
If you own or manage a building in the Brock lands, there is a specific ask worth making of any roofer bidding your building, including us: ask them to walk the perimeter with you and tell you what they see. Most of a flat membrane looks much the same to a non-roofer. The edge does not — once someone points out a loose cleat, a backed-out fastener or a discontinuity in the metal, you will see it yourself for the rest of the walk.
That is a reasonable test of whether the person quoting your building understands what actually takes it off.
Reviews From Customers on Flat Roofs Like Yours
Our business in Aurora had several leaks in the roof to our shop. Crown Roofing was amazing to deal with. Their worker Arvin was such a great guy and was really thorough in explaining where all the leaks were. He took photos to show us where the leaks were coming from. They also found a forth leak and fixed it in good faith without billing us. I can not express just how much we loved working with Arvin.
Amanda Helps · Google review
I waited for all seasons before giving this review as I wanted to give a transparent and accurate review. I received multiple quotes and decided to use them to replace the roof on our building.
Susan Mahabir · Google review
Rated 4.8 on Google.
Storm Damage, Permits, Solar and Edge Metal
We lost some edge metal in a storm. Is the rest of the roof at risk?
Yes, and it should be treated as urgent rather than cosmetic. Displaced edge metal leaves the membrane with an exposed leading edge, and from that point progressively less wind force is needed to peel it further — which is why a partial edge failure so often becomes a much larger one in the next weather. The immediate job is to secure the edge and make it watertight, and then to check the length of perimeter either side of the damage, because the fasteners that let go are rarely the only tired ones. Photograph everything before anything is touched; your insurer will want it. You can call us at any hour for the securing part — that is what the emergency line is for.
Do we need a permit to re-roof a commercial building here?
It depends on the scope, and Pickering is more specific than most. The City lists roofing or roof covering with no structural work as not requiring a permit, and lists structural or material alterations as requiring one — so a like-for-like covering replacement and a job that touches deck, framing or the assembly are treated differently. Worth flagging: the City explicitly lists green roofs and solar panels as requiring a permit. The exemption also sits among items written at house scale, so we confirm the position against your actual scope with the City before we price rather than relying on a general reading, and we prepare and file where one is needed.
We're considering solar. Does exposure change that decision?
It changes the engineering, and on a lakefront site it is a real consideration rather than a formality. Panels and racking add both weight and a new wind-catching surface to an assembly whose uplift loads are already highest at the perimeter, and the City of Pickering requires a permit for solar panels specifically. The structural review is the important part — not just whether the deck carries the static weight, but what the array does to uplift at the edges and corners. The other thing to sort out before anything else is sequencing: if the membrane is past the middle of its life, replace it before the array goes on, because removing and reinstalling panels to get at the membrane underneath is an expensive way to learn that lesson.
Our roof is fine in the middle. Why would you look at the edge?
Because that is where the load is and that is where the failures start. Wind uplift on a low-slope roof is not spread evenly — the perimeter carries roughly twice what the field does and the corners around three times, which means the parts under the most stress are the parts a conventional walk-around barely looks at. Canadian roofing guidance is direct that most wind-related roof cover failures involve perimeter flashings that were poorly designed or installed, and North American post-storm investigation has attributed close to sixty per cent of system failures to problems starting at the perimeter. A sound field tells you the membrane is in good order. It tells you nothing at all about whether the roof will stay on.
Have a Roofing Crew Look at the Edge Before the Weather Does
If your building sits in the Brock lands or anywhere else with a clear run to the water, the perimeter is the part of your building that decides how the next storm goes. It is also the part that almost never gets inspected properly.
Call (416) 744-7788 or email info@crownroofing.ca. We will walk the edge and the corners, scan the perimeter for water that has already found its way in, and tell you plainly whether the securement is doing its job.
We cover the whole of Pickering and the rest of Durham — the Brock lands, Whites Road, the Innovation Corridor and out through Seaton — and the same crews handle every part of it: flat roofing repairs, planned maintenance, perimeter re-securement, full replacement and new work on a construction site. One trade, one company, our own people.
If somebody has already handed you a replacement price, bring it. A second opinion on an exposed building is worth having, and about half the time the honest answer is that the field has years left in it and the money belongs at the edge instead. That is not a smaller project. It is the right one. Our roofing crews will tell you which it is before anybody prices anything, and the survey that settles it costs a fraction of the roofing it saves you.
Crown Industrial Roofing · 227 Queens Plate Dr Unit #3, Etobicoke, ON M9W 6Z7
The paperwork, sorted up front
✓ Licensed and WSIB covered, with comprehensive general liability insurance.
✓ Crews holding current safety certification. Ask and the certificates are yours.
✓ On new roofs, manufacturer-backed warranties on materials and a workmanship warranty of up to 15 years from Crown.
✓ Seasonal inspections, spring and fall, cost you nothing.