Cal. Bus. & Prof. Code § 7026.3
For the purpose of this chapter, "contractor" includes any person who installs or contracts for the installation of carpet wherein the carpet is attached to the structure by any conventional method as determined by custom and usage in the trade; except that a seller of installed carpet who holds a retail furniture dealer's license under Chapter 3 (commencing with Section 19000) of Division 8 shall not be required to have a contractor's license if the installation of the carpet is performed by a licensed contractor and the seller so certifies in writing to the buyer prior to the performance of the installation, which certification shall include the name, business address, and contractor's license number of the licensed contractor by whom the installation will be performed.
Ca. Bus. and Prof'l. Code § 7026.3