Free Flat & Commercial Roof Cost Calculator
Estimate what a new flat roof, a recover, a coating or a leak repair should cost for your building, using typical 2026 prices for the Wausau area. Change the options and the estimate updates instantly. When you want a real number, send it to us for a written quote.
Your roof
| Material | Estimate | Typical life |
|---|
Typical Wausau, WI prices for 2026. This is an estimate, not a quote.
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Commercial and flat roof cost per square foot
These are the installed ranges the calculator uses, including the membrane, insulation, standard flashings and edge metal. Small roofs, wet insulation, a second layer to tear off, lots of rooftop equipment and taller buildings push a job toward the top of the range or above it.
| System | Replacement / sq ft | Recover / sq ft | Typical life |
|---|---|---|---|
| TPO | $6.00 – $12.00 | $4.00 – $8.00 | 15–25+ years |
| EPDM (rubber) | $5.50 – $11.00 | $4.00 – $7.50 | 20–30 years |
| PVC | $7.00 – $14.00 | $5.00 – $9.00 | 20–30 years |
| Modified bitumen | $5.00 – $10.00 | $4.00 – $7.50 | 15–20 years |
| Silicone coating | $2.50 – $5.00 | 10–20 years per application | |
| Acrylic coating | $2.00 – $4.00 | 10–15 years per application | |
What the calculator accounts for
- Tear-off or recover. A recover skips the tear-off but is generally allowed only over a single dry layer. Choose two layers and the calculator prices a tear-off. See recover vs. replacement.
- Wet insulation. Leaks soak the insulation under the membrane, and every wet board gets replaced. That’s the biggest hidden cost on old roofs.
- Roof size. Small porch, addition and garage roofs carry small-roof pricing and a minimum job size.
- Equipment and height. Every unit, vent and skylight needs its own flashing, and taller buildings need hoisting or a crane.
Not covered: deck replacement, new drains, tapered insulation to fix ponding, and energy-code insulation upgrades. Those are priced after an assessment. More detail in the 2026 flat roof replacement cost guide.
Roof cost calculator: FAQs
It gives a realistic range for typical jobs in the Wausau area, built from the same ranges in our cost guide. It is not a quote. A written price needs someone on the roof: core cuts show how many layers there are and whether the insulation is wet, and those two things move the price more than anything else.
Most commercial single-ply replacements run about $6–$13 per square foot installed, depending on the membrane, insulation, tear-off and how many rooftop units and edges the roof has. A qualifying recover is often $4–$8, and a silicone or acrylic coating $2–$5.
Multiply the building’s length by its width in feet; a flat roof is very close to the building footprint. Online map tools with a measuring feature work well for larger buildings. Add a little for parapet walls and overhangs, and don’t go on the roof yourself to measure it.
Setup, edge metal and wall flashings cost about the same whether the roof is 300 square feet or 3,000, so on porch, addition and garage roofs they make up a much bigger share of the price. That is why the calculator applies small-roof pricing and a minimum job size.
Usually by more than half, if the roof qualifies. Coatings only work over a roof whose insulation is still mostly dry, which is why the calculator switches to replacement when you choose a lot of wet insulation. See are roof coatings worth it?