Requirements and Worksheet
When and how to get a building permit for a reroof project. A permit is required if any of the conditions below apply. To get a permit, complete the Reroof Project Worksheet below and submit the worksheet with a Building Permit Application.
Exceeding the 25% rule. A permit is required when 25 percent or more of an existing roof is to be reroofed in any 12-month period. Less than 25 percent is considered a repair and doesn’t require a permit.
Separate permits for each onsite structure being re-roofed. Secure a separate permit for each building onsite undergoing a reroof project. Exception: On a single-family property, both a detached garage and the dwelling can be re-roofed under the permit obtained for the main house.
Non-residential, multifamily, and historical properites need prior Planning Division review. The Planning Division must first approve reroofing projects for non-residential, multifamily (three or more units) or historical properties listed on the Historical Resources Inventory before you get a building permit. Call the Permit Center to speak with a planner.
Re-roofing Project Specifications and Requirements
Keep your building and inhabitants safe and follow these requirements
- Nails or staples must extend at least 3/4-inch into or through the sheathing, except where such penetrations would be visible at eaves or porch overhangs.
- Spacing and location of fasteners are to be according to the manufacturer's installation instructions.
- Nail heads must be flush with shingles: Do not drive heads into shingles.
- Double-wall Type B flues require a 1-inch minimum clearance to combustibles.
- A separate mechanical permit and inspection are required if the flue is cut or altered in any way.
- Class C minimum rating is required by California law, whether new or re-roof.
- Wood shake and shingles must be a fire-resistant type.
- Flashings may be re-used if in good condition.
- Exposed edges of wood sheathing are to covered with L metal or equal.
- Counter-flashing is required where the roof meets a vertical surface, such as a wall or chimney.
- Most tile reroof applications require EVERY tile to be nailed; follow the manufacturer’s specifications.
- Maximum number of composition roof covers allowed: 2
- Use only metal tiles listed for this purpose to overlay wood shake roofs.
- A maximum of two built-up roofs is possible.
- An engineering analysis of the roof supporting structure is required if the total weight of all roof coverings exceeds 7 pounds per square foot.
- Solid sheathing is required for all roof covering materials except for wood shingle and shake.
- Plywood and OSB board exposed to weather (underside of eaves) must have exterior grade glue (Exposure 1).
- Skylight installations require a separate building permit and inspection.
- Composition roof: minimum slope of 2 in 12
- Wood shake roof: minimum slope of 3 in 12
- Interlocking concrete tile roof: minimum slope of 4 in 12
- Install according to the manufacturer’s instructions.
For a re-roof project, typically only one inspection is required, either an in-progress
inspection or a final inspection. If the inspection identifies the need for minor corrections, self-certification of the completed corrections may be done by the roofing contractor or property owner. Instructions for self-certification are on the Inspection Request Form and the Re-Roof Inspection Notice. For an inspection, follow these rules:
- The Permit Card must be on-site at all times.
- Provide a ladder to enable access to all levels of the roof for inspection. Inspectors do not carry ladders.
Re-Roof Project Permit Fee
The Residential fee is $188.00 per building. The Non-Residential fee is $313.00 per building. Taxes and administrative fees will apply.
Cost-Saving Tip: Doing several projects under one building permit is a good way to save money on remodeling costs. A re-roof project can be done under a building permit issued for other improvement work.
Additional Permits for Moving or Altering Rooftop Equipment
If your reroofing project involves moving or altering rooftop equipment such as solar installations, air conditioners, or heating equipment, additional sub-trade permits (electrical or mechanical, for example) will be required and associated fees will apply.
A PDF handout version of this information is available on our Building Handouts and Forms page.