Short answer
TPO is a white membrane for flat and low slope roofs, with heat welded seams. It comes in wide rolls (Hunker cites 6 to 12 feet) and is fastened, glued or ballasted. Because welding seams takes a hot air welder and skill, most TPO roofs are installed by roofers. For a DIY flat roof, EPDM or self-adhered modified bitumen is usually the easier choice.
How TPO works
TPO is a thermoplastic: heat softens it, and two sheets pressed together while hot fuse into one. Roofers lay the sheets with overlaps, then run a hot air welder along each seam. The field is fastened to the deck, glued, or held down with ballast (Hunker). Hunker gives TPO a life of 10 to 20 years and a cost of about $5.50 to $6 per square foot for materials and installation.
TPO vs EPDM at a glance
| TPO | EPDM | |
|---|---|---|
| Color | Usually white | Usually black |
| Seams | Hot air welded | Taped or glued |
| Roll width (typical) | 6 to 12 ft | Wide sheets; 10 x 25 ft is common retail |
| Life (estimate) | 10 to 20 years | More than 20 years |
| DIY friendliness | Low: welding skill | Higher on small roofs |
Figures from Hunker. More on the rubber option in the EPDM guide.
If you are hiring a roofer
Ask every bidder the same questions so the quotes compare:
- Thickness. Which membrane thickness, and which maker?
- Attachment. Mechanically fastened, fully adhered or ballasted, and over what cover board or insulation?
- Tear-off. Is the old roof coming off, and is damaged deck replacement priced per sheet?
- Edges and drains. What happens at walls, edges, drains and penetrations?
- Warranty. What does the maker cover, what does the installer cover, and for how long?
If you are set on doing it yourself
Buy membrane, the maker’s accessories and a hot air welder made for roofing seams, practice welds on scrap, and test each seam with a probe. For a small roof, compare the time and tool cost with peel-and-stick roll roofing or EPDM, which need no welding.
Questions people ask
Is TPO better than EPDM?
Neither is better for every roof. TPO is usually white and reflects sun, and its seams are welded. EPDM is usually black rubber and its seams are taped or glued, which is easier for a beginner. Hunker estimates TPO life at 10 to 20 years and EPDM at more than 20.
Can I install TPO myself?
It is possible on a small roof if you buy or rent a hot air welder and practice on scrap, but seam welding is a skill. A bad weld leaks. Most homeowners are better served by EPDM or peel-and-stick, or by hiring a roofer for TPO.
What is TPO on an RV?
Some RVs have TPO roof membranes. RV TPO uses RV specific sealants; one RV TPO maker says only its own sealants may touch its membrane. Check what your RV has before buying anything. See the RV roof guide.
How wide are TPO rolls?
Hunker describes TPO as coming in 6 to 12 foot wide rolls. Narrower rolls mean more seams, and seams are where problems start.
Sources
Last reviewed October 12, 2026. Products and listings change; check the data sheet and wrapper before you buy, follow the maker’s instructions, and check your local building code.