California Code, Business and Professions Code - BPC § 7045

This chapter does not apply to the sale or installation of any finished products, materials, or articles of merchandise that do not become a fixed part of the structure, nor shall it apply to a material supplier or manufacturer furnishing finished products, materials, or articles of merchandise who does not install or contract for the installation of those items. The term “finished products” shall not include installed carpets or mobilehomes or mobilehome accessory structures, as defined in Section 7026.2.

This chapter shall apply to the installation of home improvement goods, as defined in Section 7151.