San Francisco County Municipal Code Ch. 14 Exterior Walls

SECTION 1402 – PERFORMANCE REQUIREMENTS 1402 Add a section as follows:

Provisions shall be made at the outer edge of all projections and appendages to control rainwater backflow

under the projection. Ventilation shall be provided for all enclosed spaces of exposed soffits, bays and other projections in wood framed construction. Where an uncovered balcony or deck with an impervious surface exceeds 200 square feet (18.58 m2) in area, drainage shall be conveyed directly to a building drain or building sewer or be conveyed to an approved alternate location based on approved geotechnical and engineering design. Chapter 15

ROOF ASSEMBLIES AND ROOFTOP STRUCTURES SECTION 1501 – GENERAL

For qualified historical buildings or properties, see 2025 California Historical Building Code. SECTION 1502 – ROOF DRAINAGE

All storm- or casual water from roof areas which total more than 200 square feet (18.58 m2) shall drain or be conveyed directly to the building drain or storm drain or to an approved alternate location based on approved geotechnical and engineering design. Such drainage shall not be directed to flow onto adjacent property or over public sidewalks. Building projections not exceeding 12 inches (305 mm) in width are exempt from drainage requirements without area limitations. SECTION 1505 – FIRE CLASSIFICATION

Class B or better roof coverings shall be used on all buildings.

2. Detached accessory structures with a roof of less than 200 square feet (18.58 m2) may have roof coverings of Class A, B or C. Table 1505.1 Revise the table as follows: TABLE 1505.1 – MINIMUM ROOF [ ← ] COVERING CLASSIFICATION FOR TYPES OF CONSTRUCTION

IA IB IIA IIB IIIA IIIB IV VA VB B B B [ ← ] B B [ ← ] B B B [ ← ] B

SECTION 1507 – REQUIREMENTS FOR ROOF COVERINGS 1507.8.5 Add the following sentence at the end of the paragraph: Untreated wood shingles shall not be permitted. 1507.9.6 Add the following sentence at the end of the paragraph: Untreated wood shakes shall not be permitted.

SECTION 1511 – ROOF TOP STRUCTURES 1511 Add the following section:

Occupiable roof decks may be constructed of wood when the following conditions are met:

1. The occupied roof deck is less than 500 square feet (46.45 m2) in area.
2. The deck boards are spaced not greater than 1/8 inch (3.2 mm) apart.
3. Any open space around the perimeter between the deck and the roof surface shall be enclosed to within 1 inch (25.4 mm) of the roof surface.
4. The decking is constructed of fire-retardant- treated wood approved for exterior use, or 2-inch (50.8 mm) nominal all heart redwood. Guardrails and fences may be constructed of any material permitted by this code.
5. The deck is installed on top of a Class A or B fire-resistive roof assembly. The deck shall not be considered part of such roof assembly.