Three things worth checking on any low-slope quote
1. Ask for core cuts. A core sample through the whole assembly shows how many roofs are already on the deck, whether the insulation is wet and what condition the deck is in. It costs very little and it turns every quote from a guess into a specification.
2. Compare systems, not totals. Membrane type and mil thickness, attachment method, insulation R-value, whether tapered board is included to correct drainage, and tear-off versus re-cover. Two quotes on the same roof can differ by half on scope alone.
3. Verify the licence. California requires a licensed contractor for any job of $500 or more in combined labour and materials. Roofing is the C-39 classification and C-39 holders must carry workers' compensation even with no employees. Check the number at cslb.ca.gov: it takes under a minute and shows status, bond and comp coverage.
Low Slope Pros is an independent directory and referral service. We do not perform roofing work and we do not vet, endorse or guarantee any contractor. Verify credentials yourself before signing anything.