TPO, EPDM, modified bitumen—get the full installed cost including tear-off, insulation, penetrations, and edge metal. No flat roof surprise on this job.
A flat roof with 10 HVAC units, 6 drains, and 20 electrical penetrations can double your labor cost versus a clean deck. Each penetration needs flashing, clamping rings, sealant, and detail work—budget 1.5–2 hours per penetration minimum. Scope this on-site, not from photos.
Most jurisdictions allow one re-cover before requiring a full tear-off. Check whether existing insulation is wet—an infrared scan before quoting prevents a change order when you pull the first layer and find soaked polyiso that now needs to be hauled away. Wet insulation adds $0.50–$1.50/sqft to disposal cost.
A TPO roof is only as good as its welds. Set minimum weld temperature (325–360°F for most membranes) and test pull frequency in your QC process. A failed weld at year 3 is your liability—building owner doesn't care which crew made the seam. Document weld checks in writing on every job.
The Roofer's Business Starter Kit includes a flat roof and shingle price book, an inspection report form, service agreement template, and change order forms. Guide from $19 — Complete Kit with all 19 templates, $49.
Get the Roofer's Kit →TPO installation pricing is driven by roof area, membrane thickness, attachment method (mechanically fastened vs. fully adhered), seam linear footage, edge detail complexity, and penetrations. This calculator builds a complete TPO installation quote from material and labor line items — so you're not underestimating jobs based on square footage alone.