Send every bidder the same written scope, then compare line by line: tear-off or recover, deck repair unit prices, insulation, membrane, flashing and drains, permits, warranty, insurance, schedule and exclusions. Only compare price once the scopes match. Check each roofer's license on the CSLB website before you decide.
Before you compare: send every bidder the same scope
Bids are only comparable if every contractor prices the same project. Property Manager Insider's guide to commercial roofing bids makes the same point: a defined scope gives contractors the same project information, which makes pricing more accurate and reduces confusion during review. One scope sheet should cover:
- Roof area and sections, and the existing system.
- Tear-off or recover.
- The insulation target.
- Drains, scuppers and flashing; penetrations and curbs.
- Access and staging, schedule windows and any rules for working over occupied space.
If you'd rather start from a proposal, we can send a good/better/best bid package you can forward to the owner. More on our roofing for property managers page.
The 12-point comparison table
| Item | What to look for | Ask if it's missing |
|---|---|---|
| 1. Scope | Roof sections and square footage measured the same way | "How did you measure the roof?" |
| 2. Tear-off or recover | Layers removed and how the existing roof is handled (see commercial roof replacement) | "Are you removing the existing roof or covering it?" |
| 3. Deck repair | A unit price per square foot for wet or damaged deck or insulation | "What do you charge if you find damage under the roof?" |
| 4. Insulation | Type and R-value, or why it's reduced; whether Title 24 is triggered (see our Title 24 re-roof guide) | "Does this meet the energy code for this re-roof?" |
| 5. Membrane or system | Product, thickness and attachment method; the CRRC cool roof rating where Title 24 applies | "Which product and rating are you pricing?" |
| 6. Flashing, drains, scuppers, sheet metal | What's replaced and what's reused (see sheet metal, flashing and drainage) | "Is the perimeter metal new or reused?" |
| 7. Permits and inspections | Who pulls them and whose cost they are | "Who handles the permit, and is the fee included?" |
| 8. Warranty | Manufacturer warranty vs. contractor workmanship warranty: what each covers and who issues it | "Who issues the warranty, and what does it exclude?" |
| 9. Insurance | Certificate of insurance (general liability and workers' comp), plus additional-insured wording if the owner or HOA requires it | "Can your broker send the certificate?" |
| 10. License | The CSLB license number on the proposal, the C-39 roofing classification, and an active status on CSLB's lookup | "What's your license number?" |
| 11. Schedule and logistics | Start window, duration, weather contingency, tenant or resident notices, staging, crane or hoist, cleanup | "How long, and what happens if it rains?" |
| 12. Exclusions and allowances | Read them line by line. This is where bids differ most. | "What isn't included?" |
Price last: how to read the number
Normalize first: same area, same scope, same allowances. Then compare price. A low number often leaves something out, such as tear-off, insulation, flashing or deck repair, and that tends to come back as change orders. Facilitiesnet makes the same point about contractor selection: even with a well-developed scope of work, low bid alone won't produce the most cost-effective roof installation.
Good, better and best options help the owner see the trade-offs between scopes before choosing one.
Five checks you can do yourself
- Look up the license on CSLB's Check a License page: status, the C-39 classification and workers' compensation coverage on file.
- Ask for the certificate of insurance directly from the contractor's broker.
- Ask for references for similar commercial buildings.
- Confirm the bidder visited the roof. Photos in the proposal are a good sign.
- Check that the license number is on the proposal. California law requires contractors to include their license number in construction contracts, calls for bid and advertising (Business and Professions Code §7030.5).
Red flags
- No site visit.
- A single lump sum with no scope.
- Pressure to sign on the spot.
- No license number on the proposal.
Presenting the pick to an owner or board
Put the table, the recommended option and the reasons on one page, and attach the bids. For HOAs, plan around board-packet timing and owner notices; see HOA and condo roofing and the roof in your HOA reserve study. In San Francisco? See commercial roofing in San Francisco.