California Code, Health and Safety Code - HSC § 114349

(a) Temporary food facilities shall be equipped with overhead protection for all food preparation, food storage, and warewashing areas. Overhead protection shall be made of wood, canvas, or other materials that protect the facility from precipitation, dust, bird and insect droppings, and other contaminants.

(b) Temporary food facilities that handle nonprepackaged food shall also protect food from contamination in one of the following ways:

(c) Notwithstanding Section 113984, this section does not apply to temporary food facilities that are approved for limited food preparation if flying insects, vermin, birds, and other pests are absent due to the location of the facility or other limiting conditions.