How to Estimate a Commercial Roofing Job | Reddit & LinkedIn

To estimate a commercial roofing job, measure the roof in squares, choose the membrane such as TPO, EPDM, or modified bitumen, decide between tear-off and recover, then price material, labor crew-days, insulation, flashing, and markup. Commercial reroofs run about $4 to $12 per square foot depending on membrane, insulation R-value, and roof access.

The difference between a profitable bid and a callback that eats your Saturday is scope accuracy. Walk the job, capture photos, and write down every variable before you put a number on paper. Guessing high loses the bid. Guessing low loses the margin.

1. Measure the roof in squares. Get accurate square footage from drawings or a measurement service, then convert to squares. One square is 100 square feet. Add waste for parapets, curbs, and penetrations.

2. Select membrane and assembly. Choose TPO, EPDM, PVC, or modified bitumen based on the building use and budget, then spec insulation R-value to meet energy code. The assembly drives both material cost and labor hours.

3. Decide tear-off or recover. A recover over one existing layer saves teardown labor and disposal, but code limits you to two total layers and the deck must be sound. Tear-off adds dumpster and labor cost but resets the assembly.

4. Price crew-days, then add markup. Estimate crew-days for tear-off, insulation, membrane, flashing, and detail work, apply your labor rate, add material and disposal, then your commercial markup and a contingency for hidden deck damage.

Commercial roofing runs $4 to $12 per square foot installed in 2026. TPO and EPDM single-ply sit at the lower end, PVC and multi-ply modified bitumen at the higher end, and added insulation to hit code can add $1 to $3 per square foot. Roof access, height, and occupied-building logistics push labor up on tight urban sites.

Once your numbers are set, speed and clarity win the job. On ContractShield you build the estimate in about 25 minutes with an AI draft ready in under a minute, then send it as a branded link the client reviews and accepts on their phone with no login. Every line shows where its price came from, so the client trusts the number and you keep control of your markup.

After acceptance, the same workspace runs the job. Tasks, photos, time tracking, change orders, and milestone invoices all live in one place, so you manage the work from the truck instead of chasing texts and email threads.

Bill on milestones so money comes in as the work progresses instead of in one lump 60 days out. ContractShield generates each milestone invoice from the accepted quote, so the numbers match and there is nothing to retype. Payments run through Stripe.

When an invoice goes past due, Collections sends a polite, then firm, then final reminder automatically, and you approve each step or let it auto-send. It recovers money you are already owed for 2% per job, 1% each side, capped at $250, with no per-lead fees, ever, with no per-lead charges and no seat fees.