Roof Replacement & Reroofing in California

Roof Replacement & Reroofing: what to know in California

A reroof is the largest single maintenance project most California homeowners ever commission, and it is the one where quotes vary most wildly for reasons that are not visible on the page. Two bids can differ by tens of thousands of dollars because one includes a full tear-off to bare sheathing, new underlayment, new flashing metal, deck repair allowance, permit and disposal — and the other includes an overlay with reused flashing.

Make every bid describe the same job

Insist that each quote states, line by line: how many existing layers are removed; the specific underlayment product and weight; whether flashing, valley metal, drip edge and vent boots are new or reused; the deck repair rate per sheet if rot is found; who pulls the permit; whether disposal is included; the manufacturer warranty and the separate workmanship warranty in years. Once all bids answer those seven points, the comparison becomes obvious — and it is frequently not the cheapest bid that wins.

What California code requires

Title 24 Part 6, the state energy code, sets minimum aged solar reflectance and thermal emittance for most residential roof replacements, with the exact threshold depending on climate zone, roof slope and attic insulation. Ask which rated product is being installed and to see its Cool Roof Rating Council listing. The California Residential Code separately prohibits installing a new covering over two or more existing layers, or over a deteriorated or water-soaked deck. And in a Very High Fire Hazard Severity Zone or State Responsibility Area, the assembly must be Class A with the ember-resistant detailing in Chapter 7A.

Timing and disruption

A typical single-family reroof runs a few days to a couple of weeks depending on size, material and whether deck repair is needed. Schedule outside the November-to-March storm window if you can, and expect noise, a dumpster on the driveway and nails in the yard — ask whether magnetic sweep is included. Permits and inspection are normal; a contractor who suggests skipping the permit is moving liability onto you.