Health and Safety Code § 9626
ARTICLE 2. Structural and Material Requirements of Community Mausoleums and Columbariums
Except as otherwise provided in this chapter, all materials used in the construction, ornamentation, or embellishment of mausoleums or columbariums shall be incombustible. This section shall not apply to crypt vents, temporary openings or partitions, interior doors, fixtures, furniture, or furnishings.