Residential Reroof

A building permit is required when more than 200 square feet of roof covering is installed, repaired or replaced. Residential Reroof Permits are same day permits.


New roof coverings can only be applied over a single layer of existing roofing. If a roof already has two layers of covering, both existing layers must be removed before the new roof can be installed.
The following conditions prohibit the installation of a roof overlay even if there is just one existing roof covering:
  • Existing roof covering is wood shake, slate, clay tile, cement tile, or asbestos-cement tile.
  • Existing roof covering is water soaked or has deteriorated to the point that it is not adequate as a base for additional roofing.
  • Manufacturer specifications prohibit overlay applications for that particular product.


    Installing roofing materials that are over 5 pounds per square foot may require a structural review depending on the condition of the existing roof framing. Please provide the product specification sheet forverification of the weight and be prepared to provide roof framing information if required.
    Safe roof access must be provided to the inspector. The permit holder shall provide a safe ladder, free of defects and rated for a minimum of 250 pounds. The ladder shall extend 3 feet above the roof and shall be secured to the building. Without a safe means to access the roof, the inspection may be failed.The first inspection will be a “pre-roof”. The inspector will visit the site after the existing roofing has been removed or prepared for a new layer. The inspector will be looking for dry-rot, damaged sheathing,flashing and underlayment placement. For projects that involve new plywood sheathing, there will an additional inspection for ”roof nailing”. These are then followed by the final inspection where the inspector will check the completed roof and verify placement of spark arrestors, gutters and other associated work.


    If the property is in a neighborhood with a home owners association, the applicant should confirm that the materials meet the design guidelines. Also, the applicant should verify any significant changes in roofing color or material with the City of Hayward Planning Department.

    T-24 ENERGY: “Cool Roof” Requirements

    The California Energy Commission requires that new roofs installed in certain applications meet cool roof requirements. The term “cool roof” refers to roofing materials that are designed to reduce the amount of outside heat transferred into the building. Roofing manufacturers will indicate if their product is classified as a cool roof by labeling it on the materials if the following conditions exist: 50% or 2000 ft2 (whichever is less) of roofing are being replaced over conditioned spaces. Steep roofs (>2:12 slope) shall comply with a 0.20ASR and 0.75TE. Flat roofs (<=2:12 slope) shall comply with a 0.63ASR and 0.75TE. Alternatively, a Title 24 energy consultant may provide exceptions and other compliance options with a report.
    NOTE: Single-Family Residential Reroofs Do not require a cool roof in our climate zone.


    • SPARK ARRESTORS: All fireplace chimneys shall have spark arrestors installed prior to final.
    • VENTILATION: Verify that attic and rafter spaces have a net free ventilated area of not less than 1 square foot of ventilated area for each 150 square feet of roof area.
    • FLASHING: Damaged flashing shall be replaced. Valley flashing shall have a min. slope of ¼” per foot and shall be 26 gauge galvanized sheet metal. Exposed plywood edges shall be covered with sheet metal.
    • PLYWOOD SHEATHING SPACING: Plywood and OSB sheathing shall be spaced at 1/8” apart.
    • ROOF DECK NAILING: Sheathing joints shall fall over existing rafters whenever possible and shall be nailed with 8d box nails 6” on center at the edges and 12” on center for field nailing.
    The contractor is responsible for verifying that the roofing installation meets all applicable requirements of the California Building Code, California Residential Code, California Energy Code and all product specific installation instructions.

Check Status Master Fee Schedule