The membrane with welded seams
TPO is a single-ply roofing membrane with heat-welded seams. The roof proposal should identify the membrane, attachment, insulation, flashing details and seam inspection requirements. Compare the complete assembly and installation scope rather than choosing from membrane type alone.
Seam preparation and welding need to follow the selected manufacturer’s instructions. Ask how the installer will check the completed seams and document any repairs. A general seam-strength claim is not proof of the quality of an installed roof.
What TPO does well
- Reflects sunlight. White TPO can reduce solar heat absorbed by the roof. Annual savings depend on climate, insulation and heating and cooling demand. Compare summer cooling benefits and winter heating effects using the Department of Energy cool-roof guide; roof color alone does not establish a saving for your building.
- Plan for local conditions. Review drainage, insulation, rooftop access and the selected assembly when planning the roof. Membrane type alone does not establish how the complete roof will perform through winter.
- Plan installation around the building. Compare attachment, roof access, tear-off work and weather protection in the written schedule. A large open deck does not establish the fastest system or guarantee completion within a particular season. For a property in Chicagoland, Carol Stream or Bolingbrook, include the address and access restrictions when requesting a schedule.
60 mil or 80 mil
When comparing 60 mil and 80 mil options, ask for the product data sheet, reinforcement details and the complete assembly specification. Compare total membrane thickness and the weathering layer above the reinforcement along with the other components; one measurement alone does not establish durability.
Compare the proposed membrane thickness and complete assembly in the written scope. Ask what changes between the options, including installation details, insulation, cover board and warranty eligibility. Do not assume the only difference is membrane cost or that a thicker membrane is always the least-cost durability improvement.
Where TPO is the wrong answer
Compare TPO with EPDM and modified bitumen against the building’s actual conditions. Roof geometry and penetrations affect detailing, but do not by themselves select the best membrane. Where grease, oils or chemicals may reach the roof, identify the substance and exposure and obtain project-specific compatibility guidance. GAF’s chemical-resistance guidance explains why exposure conditions matter and why chemical damage may be excluded from warranty coverage.
How we build a TPO roof
Tear-off or recover gets decided by what the core samples say, not by what’s cheaper to sell. Wet insulation comes out, because burying it under new membrane is how you buy the same leak twice. Then the assembly goes together in order:
- Confirm the insulation requirements for this roof. The proposal should identify the existing assembly, planned tear-off or recover, and insulation specification. Verify the requirements that apply to the building and project with the local authority before selecting the assembly.
- Plan protection for service traffic. Identify walkways and work areas around rooftop equipment, and specify suitable protection in the assembly. Do not assume cover board makes the membrane puncture-proof.
- Specify the membrane attachment. Select an assembly for the deck and required performance, then compare the complete installation scope. Attachment labels alone do not establish cost, wind resistance or noise performance. See GAF roofing system specifications for examples of distinct assemblies.
- Every seam heat-welded and probed. Welds get tested with a seam probe, not eyeballed from ten feet.
- Every curb and penetration flashed in manufacturer-spec detail. Flashings are where roofs leak. They get the slow, careful work.
Warranty coverage depends on the selected assembly and the written terms. Review manufacturer material coverage and installer workmanship coverage separately; do not assume a material warranty covers installation. Any proposed manufacturer system guarantee must be confirmed for the specific project, including eligibility, exclusions and maintenance requirements. See GAF’s commercial warranty comparison for examples of how coverage differs. This reference does not establish a manufacturer affiliation or project eligibility.
What a TPO roof costs
A useful TPO estimate identifies tear-off or recover, insulation, deck repairs, edge details, access and flashing work. Compare itemized scopes for the same building before choosing a system. Request a roof assessment to discuss the existing conditions and proposed work.
How the estimate works
No sales calls, no pressure, no guy in a polo following up every day. You fill out the form. Requests receive a response within 24 hours. On-site timing is confirmed separately based on location, weather, safety and roof access. The assessment documents roof conditions and may include core samples when needed to evaluate the existing assembly. You get an itemized scope by email covering system options, insulation plan, schedule, and warranty terms. Share it with your ownership group or facilities team and decide on your own time.
Frequently Asked Questions
How long does a TPO roof last in Chicago?
TPO service life depends on the roof assembly, installation, drainage, exposure and maintenance. Membrane thickness alone does not establish a lifespan for your building, and a warranty term is not a service-life promise. Have the roof condition assessed and compare the proposed assembly and written coverage before choosing a system.
TPO or EPDM, which should I pick?
Compare the complete roof assemblies for your deck, insulation, drainage, rooftop equipment and expected exposure. TPO uses heat-welded seams; membrane type or roof size alone does not establish the better choice. Ask the assessment to explain the proposed detailing, installation scope, maintenance needs and written warranty terms for each suitable option.
Can you install TPO over my existing roof?
A recover may be an option, but dry core samples and the layer count alone do not establish eligibility. The assessment must consider the existing assembly, moisture, deck condition, drainage and the proposed system. Confirm the applicable local requirements and manufacturer instructions before deciding between recover and tear-off.
Get a Free TPO Roof Installation for Chicagoland Commercial Buildings Estimate
Requests receive a response within 24 hours. On-site timing is confirmed separately based on location, weather, safety and roof access.