California Building Code Requirements for Building a Deck

Basic Construction

• The California Building Code is designed in accordance with the International Building Code, which sets forth several deck-related requirements. The IBC recommends inspecting decks, balconies or porches for split or rotten wood, loose or missing joinery elements or any damaged or loose support beams, planks or handrails. According to the code, decks must support at least 40 pounds per square foot in addition to their own weight. Decks of the balcony-type, freely supported without additional posts, must support 60 pounds per square foot. Common code violations include faulty connections, improper railings and missed inspections.

Means of Egress

• If decks are placed outside one of a home's egress routes, it must comply with certain standards to allow smooth and timely evacuation in case of emergency. The longest side of the balcony or deck must be open, with sufficient space for any noxious gases or smoke to dissipate. If the exterior balcony complies with the requirements as a well-ventilated exterior portion of the egress route, then the maximum allowable egress distance may be extended by the length of the deck, up to 100 feet.

Guards and Railings

• The California Building Code requires guards along all landings, platforms, elevated walking areas and mezzanines situated 30 inches or more above the ground. The guards must measure at least 42 inches in height. If the guards are made with balusters, the spacing must be such that a four-inch sphere cannot pass through any gaps. If your deck is more than 70 inches from the ground, you must have 42-inch guardrails. All guards must hold at least 200 pounds of horizontal weight at any point. If the deck features stairs, a stair railing is required on both sides; the railings must be continuous along the length of the stairway and measure between 34 and 38 inches in height. The stairs, themselves, must measure at least 35 inches wide, with a maximum rise of eight inches and depth of 9.25 inches, per step.