When three contractors bid the same roof and come back 40 percent apart, the difference is almost never pure margin. It is scope. One priced a full tearoff, one priced a recover, and one left the wet insulation in place. Until you can see scope differences clearly, the prices mean nothing.
The six things every real proposal states
- System and thickness — "60-mil TPO, fully adhered" not just "new rubber roof."
- Tearoff or recover — is the existing roof coming off? All layers? What happens when wet insulation is found?
- Insulation spec — type, thickness, R-value, and whether it meets current Massachusetts energy code.
- Details — how edges, drains, penetrations, curbs, and walls are being flashed. This is where roofs fail.
- Warranty — manufacturer warranty type and term, plus the contractor's own workmanship warranty, in writing.
- Exclusions — what is NOT included. Deck repairs, plumbing, electrical disconnects, unforeseen conditions. Every honest proposal has exclusions; the dishonest ones hide them.
Red flags
- No membrane thickness stated — the cheapest bid is usually cheapest because of what it does not say.
- "Price may change based on conditions" with no unit pricing — hidden conditions should be priced by written change order with unit rates agreed up front.
- No mention of insulation or code compliance — a reroof that ignores current energy code can fail inspection, and fixing it mid-project is expensive.
- Vague warranty language — "20-year warranty" without saying who backs it, what it covers, and what voids it.
- No proof of insurance specific to roofing — ask for certificates naming your property.
Comparing bids that refuse to line up
Build a simple grid: system, thickness, tearoff scope, insulation R-value, detail scope, warranty, exclusions, price. Fill it in from each proposal. Anything a proposal does not state, call and ask — the answer in writing becomes part of the contract.
If a bid is dramatically lower, find the scope line that explains it. If you cannot find it, that is the answer.
This grid is also exactly what an owner's-side consultant builds for you. Having someone on your side of the table who reads roofing proposals every week turns a guessing game into a decision.
Talking through this decision on a real building?
A free assessment gets you a straight answer for your specific roof — not a generic pitch.