What the materials are
TPO is a thermoplastic single-ply membrane with heat-welded seams. EPDM is a synthetic-rubber membrane joined with manufacturer-approved seam systems. Color, sheet size, attachment options, accessories, and warranty assemblies vary by manufacturer.
Compare assemblies, not slogans
- Existing roof and deck condition
- Tear-off or recover eligibility
- Insulation, cover board, and vapor-control design
- Attachment and wind-uplift requirements
- Drainage, penetrations, curbs, walls, and perimeter details
- Construction access and occupied-building constraints
- Manufacturer inspection and warranty terms
Where TPO may fit
TPO may suit owners seeking a light-colored roof and heat-welded seam system. The proposed membrane, reinforcement, thickness, attachment, welding procedures, details, and approved installer matter more than the category name.
Where EPDM may fit
EPDM may suit projects where a flexible rubber membrane and its available attachment and flashing systems match the building's needs. As with TPO, seam preparation, substrate, details, drainage, and installation control are decisive.
Do not accept blanket lifespan, energy-savings, or Minnesota-performance promises. Ask each bidder to cite the exact manufacturer's current technical documents and warranty, and have the design reviewed where project complexity warrants it.
Bid both systems fairly
If the board wants alternatives, issue one base scope with defined existing conditions and performance requirements. Require each bidder to list system components, attachment, details, exclusions, warranty, maintenance requirements, and assumptions. Keep roof-area measurements and repair allowances consistent.
Compare the right roof assemblies
Hoyt Exteriors can document current conditions and prepare a clearer commercial or multifamily roof scope.
Request a Commercial Roof Assessment