Commercial
Commercial roofing, explained the way a building owner needs it
Most commercial roof spending is decided by somebody who did not choose the roof, inherited no paperwork about it, and has to explain the number to a board or a budget committee. This section is written for that problem.
The systems
- 01TPOHeat-welded thermoplastic, reflective, the default on large simple roofs. Where it performs and where it does not.
- 02PVCThe grease and chemical answer. Restaurants, kitchens and anywhere with an exhaust stream that eats membranes.
- 03EPDMRubber. Long-proven, easy to repair, and still the right answer on a lot of simple roofs.
- 04Modified bitumenMulti-ply asphalt. Redundancy, foot traffic tolerance, and complicated small roofs.
- 05Commercial metalStanding seam and retrofit systems on sloped commercial buildings.
The programs
- 01Roof maintenance programScheduled inspections, a roof file, and the documentation most warranties quietly require.
- 02Emergency leak responseWhat happens when water is coming into a tenant space at four in the afternoon.
- 03By building typeWarehouse, retail, restaurant, church, school, multifamily and medical office — what is different about each.
Choosing a system without being sold one
Almost every commercial roofing conversation starts in the wrong place — with a membrane — when it should start with what the building does. Six questions decide the answer, and a contractor who does not ask them is recommending whatever they buy in volume.
| Question | Why it decides the system |
|---|---|
| What comes out of the exhausts? | Grease and many solvents destroy some membranes and not others. This single question rules out options before anything else is considered. |
| Does water stand on it? | Ponding punishes seams and any system that depends on adhesive laps rather than welds. |
| How much rooftop equipment is there? | Units, curbs, conduit and gas lines mean flashing detail and foot traffic, and some systems tolerate both far better. |
| How exposed is the building? | Attachment method and perimeter detailing are wind decisions, and wind is what this market records. |
| How long do you intend to own it? | A ten-year horizon and a thirty-year horizon are genuinely different answers, and pretending otherwise is how buildings get over-specified. |
| What is under the membrane? | Existing insulation, deck type and how many layers are already up there decide whether this is a recover or a tear-off. |
The honest short version: restaurants and grease exhaust point to PVC, large simple roofs point to TPO, simple roofs with few penetrations and a long horizon suit EPDM well, complicated small roofs and heavy foot traffic suit modified bitumen, and a sloped metal building is its own conversation.
Recover or tear off
- Recover
- A new membrane installed over the existing roof, usually with a cover board or new insulation between. Less disruption, less disposal, and it depends on the existing roof being dry and on the code limit for layers.
- Tear-off
- Everything down to the deck. It is the only way to see the deck and to deal with wet insulation, and it is the right answer whenever there is trapped moisture.
- How anyone knows
- Core cuts, and where it is worth doing, an infrared or moisture survey. A recommendation made without either is a guess about the most expensive variable in the job.
Where the money actually goes wrong
- Wet insulation left in place under a new membrane. It does not dry out. It corrodes the deck and it is why some new roofs fail early for no visible reason.
- Perimeter and corner attachment specified as if the roof were one uniform field. Wind uplift is concentrated at edges and corners, and that is where blow-offs start.
- Drainage ignored. A roof that ponds was usually built that way, and a new membrane over the same slope ponds identically.
- Details rushed at penetrations. Nearly every leak on a commercial roof is at a curb, a pipe, a drain or a transition, not in the field.
- No maintenance after handover, which quietly voids a good part of the warranty that justified the specification.
Need a roof assessed, a bid reviewed, or a capital year defended to a board?
Talk to us about the buildingCan you work around our operating hours?
Yes, and on some building types it is the only way the work can be done — restaurants, medical offices, occupied schools and retail all have windows when roofing is and is not acceptable. It belongs in the scope, not in a conversation on the first morning.
Do you provide documentation for a bid or RFP process?
Yes. That means a written scope that names the system, the attachment, the insulation and the flashing details, so that competing bids can be compared on the same basis rather than on a single number.
What about warranties?
Membrane manufacturers offer system warranties with conditions attached, and those conditions normally include installation by an approved contractor and documented maintenance. What matters for a building owner is knowing exactly what the warranty covers, what voids it, and who administers it.
Is my building too small to be commercial work?
No. A small flat roof over a shop or an office suite is the same trade and the same detailing questions as a warehouse, just fewer squares of it.
All work is performed by licensed and insured local roofing professionals.