What a re-roof in San Dimas has to comply with

What California requires everywhere

State-level requirements sit underneath everything above. They are included because more than one of them is commonly misstated, and because a homeowner who knows them can tell a careful quote from a careless one.

Tear-off waste and where it goes

CALGreen requires 65 per cent of nonhazardous construction and demolition waste to be diverted from landfill — but that chapter applies to additions and alterations that increase a building's conditioned area, volume or size, and a straight re-roof does not. So the state mandate generally does not reach a re-roof.

Local ordinances frequently do, and the state code expressly lets a city be stricter. Plenty of cities capture roofing through their own construction and demolition rules by permit valuation, which can mean a deposit and a diversion report on an ordinary house. Ask the city before the skip is ordered rather than after.

Licensing, deposits and what has to be on the paperwork

Roofing is the C-39 classification with the Contractors State License Board. The minor-work exemption that lets very small jobs be done unlicensed rose to $1,000 at the start of 2025, but it does not apply to work that requires a permit — and a re-roof requires a permit. The practical rule is therefore simpler than the statute: a re-roof needs a licensed contractor, whatever it costs.

Deposits are capped by statute at $1,000 or ten per cent of the contract, whichever is smaller, unless the contractor carries a blanket performance and payment bond with the board. Going over it is a misdemeanour, and in a declared disaster area the court must impose the maximum fine — which says something about how often it is tried after a storm.

Licence numbers are required in all advertising and on contracts, subcontracts and bids. An advert without one is itself information. The board’s register settles it in under a minute and the minute is worth spending.

The right to cancel

The standard cancellation window on a home improvement contract is three business days, five for a senior citizen. Where the contract is to repair or restore damage from a disaster or a declared state of emergency, it is seven business days.

It exists precisely because of what happens in a neighbourhood after a storm. Nothing has to be signed on a doorstep, and if something was, the clock above is the reason to read it again tonight rather than tomorrow.

How many layers can stay on

A new covering may not be laid over the old one where there are already two applications of any type on the roof, where the existing roof or covering is water-soaked or has deteriorated enough that it is no longer a sound base, or where the existing covering is slate, clay, cement or asbestos-cement tile. In those cases the roof comes off to the deck.

Two layers is therefore the practical ceiling, and on an older house nobody knows how many are up there until somebody looks. That is the single most common reason a re-roof price changes after the work starts, and it is a fair reason to ask for the quote to state what happens if a third layer appears.

What a wildfire-zone roof actually has to include

Inside a mapped fire hazard zone the requirements go well beyond what the roof is covered with, and the extra details are exactly where a cheap job differs from a compliant one. It is embers rather than a flame front that destroy most houses in a wildfire, and every requirement below closes a gap an ember could use.

• A roof assembly meeting Class A when tested to ASTM E108 or UL 790
• On profiled tile, bird stops at the eaves and hip and ridge caps mudded in, so there is no open end for embers to enter
• Valley flashing of at least 0.019 inch (26 gauge) corrosion-resistant metal, over a mineral-surfaced cap sheet at least 36 inches wide
• Noncombustible gutters and downspouts, with an approved means of stopping leaves and debris collecting in them
• Vent screening of noncombustible corrosion-resistant mesh, no finer than 1/16 inch and no coarser than 1/8 inch

Fire classification: what is actually required, and where

Every ordinary re-roof has to meet at least a Class C fire-retardant covering. That floor applies to new roofs, to repairs and replacements, and to any existing building where over half the roof area is replaced inside a year.

Class A, the highest classification, is required where the property sits inside a fire hazard severity zone or a wildland-urban interface area, and many cities require it more widely by local ordinance. In practice, across most of south Orange County, Class A is the answer — but it comes from the fire zoning and the local ordinance rather than from a blanket statewide rule, so it is worth confirming for your address rather than assuming either way.

As of 1 January 2026 the wildfire rules live in their own book: the California Wildland-Urban Interface Code, Title 24 Part 7, which consolidated what used to be Chapter 7A of the building code and section R337 of the residential code. A contractor still citing Chapter 7A is citing something that has been superseded.