When three roofing proposals land on your desk with prices 30 percent apart, it is tempting to assume the low bidder is efficient and the high bidder is greedy. In our experience, the spread almost always comes from different scopes rather than different margins. Here is how we recommend facility and asset managers read a commercial roofing bid.
1. Existing conditions and investigation
A credible bid is built on core cuts, not assumptions. The proposal should state how many existing roof layers there are, what the deck is made of and whether moisture testing was done. If a bid says nothing about existing conditions, it is guessing, and guesses tend to return as change orders.
2. The full roof assembly
- Membrane type, thickness and attachment method
- Insulation type, thickness, R-value and whether it is tapered
- Cover board type and thickness
- Vapor retarder, if required
- Fastener pattern and wind uplift rating in perimeter and corner zones
Two TPO roofs can differ by several dollars per square foot depending on these lines alone. Energy code insulation requirements in Houston also mean a reroof often needs more insulation than the roof it replaces.
3. Deck repair allowances
Rusted metal deck is common on older warehouses. Good proposals include a unit price per square foot for deck replacement and an allowance quantity, so you know exactly what additional repairs will cost if they are found during tear-off. A proposal without a unit price leaves you negotiating mid-project.
4. Sheet metal, drains and accessories
Edge metal, coping, counterflashing, gutters, downspouts, drain bowls, skylight screens, walkway pads and roof hatches are often where scopes diverge. Check that each item is either included, excluded or priced as an alternate. Hurricane-rated edge details matter on the Gulf Coast.
5. Logistics and occupied building conditions
- Crane days and staging locations
- Interior protection below open areas
- Work hours, weekend or night work
- Dumpster placement and haul-off
- Permit and engineering costs
6. Warranty terms
Ask whether the warranty is a manufacturer No Dollar Limit warranty or a limited material warranty, what term it covers, whether wind speed coverage is included and what maintenance the owner must perform. Also confirm the contractor's own workmanship warranty length.
7. Safety and insurance
Request the contractor's experience modification rate, fall protection plan and certificates of insurance with your organization named as additional insured. Roofing is one of the most hazardous trades, and a contractor's incident becomes your problem on your property.
8. Schedule
Proposals should include estimated start date, crew size and working days. A bid that promises an impossible schedule is as risky as one that underprices the scope.
Putting it together
We recommend building a simple comparison sheet with every line above in rows and each bidder in columns. Gaps appear quickly. Our proposals are formatted to drop straight into that kind of sheet, because we would rather win on a fair comparison than on an incomplete one.
This article is general information for commercial property owners and is not legal, insurance or tax advice. Ironclad Commercial Roofing is a demo company and every figure above is sample content.
