Wash. Rev. Code § 19.186.030
If the customer indicates that he or she intends to obtain a loan to pay for all or part of the cost of the roofing or siding contract, the roofing or siding contractor shall not begin work until after the homeowner's rescission rights provided in RCW 19.186.020(9) have expired. If the roofing or siding contractor commences work under the contract before the homeowner's rescission rights have expired, the roofing or siding contractor or salesperson shall be prohibited from enforcing terms of the contract, including claims for labor or materials, in a court of law and shall terminate any security interest or statutory lien created under the transaction within twenty days of receiving written rescission of the contract from the customer.
RCW 19.186.030