Almost every new low-slope commercial roof in the Dayton area is one of three single-ply membranes: TPO, EPDM or PVC. All three are proven. Each has strengths that make it a better fit for certain buildings, and the wrong pick usually shows up as early seam trouble, shrinkage or a membrane that can't handle what is on the roof. Here is how they compare.
Quick comparison
| TPO | EPDM | PVC | |
|---|---|---|---|
| What it is | Thermoplastic polyolefin sheet | Synthetic rubber sheet | Polyvinyl chloride sheet |
| Usual color | White (reflective) | Black (white available) | White (reflective) |
| Seams | Heat-welded | Taped or glued | Heat-welded |
| Typical cost installed | $6 – $12 / sq ft | $5.50 – $11 / sq ft | $7 – $14 / sq ft |
| Typical lifespan | 15 – 25+ years | 20 – 30 years | 20 – 30 years |
| Grease and chemical resistance | Fair | Poor with oils | Excellent |
| Best fit | Most commercial buildings, cooled spaces | Large simple roofs, older buildings, freeze-thaw | Restaurants, food processing, industrial |
TPO: the current default
TPO is the most common new commercial roof in the US. It comes in white sheets that are mechanically fastened, adhered or ballasted, and its seams are welded with hot air so the overlaps fuse into a single sheet. That welded seam is TPO's main advantage, because seams are where most low-slope roofs leak. The white surface keeps roofs cooler in summer.
Watch for: TPO quality varies by manufacturer and thickness. A 60-mil or 80-mil sheet is worth the upgrade over 45-mil on most buildings. Welds have to be probed and tested during installation, because a cold weld can look fine and still fail.
EPDM: the proven rubber roof
EPDM has been on commercial roofs for decades, and many of them last a long time. It stays flexible in cold weather, shrugs off freeze-thaw and hail better than many people expect, and can be installed in very large sheets with few seams. It is also straightforward to repair years later.
Watch for: EPDM seams are taped or glued rather than welded, so seam workmanship matters a great deal. Older EPDM roofs often shrink and pull at the edges and corners. Standard black EPDM absorbs heat, which matters on fully air-conditioned buildings.
PVC: when the roof sees grease or chemicals
PVC is welded like TPO and is just as reflective, but it is more resistant to grease, oils and many chemicals. Restaurant exhaust vents dump grease onto roofs that softens and breaks down TPO and EPDM over time. PVC handles it. It is also a common choice where process exhaust or fuel vapors reach the roof.
Watch for: PVC costs more, and it should not be installed in direct contact with old asphalt or polystyrene insulation without the separation layer the manufacturer requires.
Roof leaking right now?
Dayton Commercial & Flat Roofing repairs, coats and replaces commercial and flat roofs across Dayton and the Miami Valley, with a written price before any work starts. Call (937) 669-7303 to request service.
Which membrane for which building
- Warehouses and distribution buildings (Vandalia, Moraine, the I-75 corridor): TPO or EPDM, chosen on drainage, wind uplift and budget. Big simple roofs are where wide EPDM sheets shine.
- Offices, medical and retail: usually TPO for the reflective surface and welded seams.
- Restaurants and strip centers with restaurant tenants: PVC, at least around the kitchen exhaust, or across the whole roof.
- Older brick buildings with parapets: any of the three, with the parapet flashing detail mattering more than the field membrane.
- Small buildings and heavy foot traffic: consider modified bitumen too.
What matters more than the membrane
A well-installed EPDM roof that drains will outlast a badly installed TPO roof that ponds, and the reverse is true too. Insulation that stays dry, flashings done to the manufacturer's details, enough slope to drain, and maintenance twice a year decide a roof's life more than the brand on the roll. See our inspection checklist and roof replacement service.