Tex. Property Code § 53.282

(a) A statement purporting to waive, release, or otherwise adversely affect a lien or payment bond claim is not enforceable and does not create an estoppel or impairment of a lien or payment bond claim unless:

(1) the statement is in writing and substantially complies with a form prescribed by Section 53.284;

(2) the claimant has actually received payment in good and sufficient funds in full for the lien or payment bond claim; or

(3) the statement is:

(A) in a written original contract or subcontract for the construction, remodel, or repair of a single-family house, townhouse, or duplex or for land development related to a single-family house, townhouse, or duplex; and

(B) made before labor or materials are provided under the original contract or subcontract.

(b) The filing of a lien rendered unenforceable by a lien waiver under Subsection (a)(3) does not violate Section 12.002, Civil Practice and Remedies Code, unless:

(1) an owner or original contractor sends a written explanation of the basis for nonpayment, evidence of the contractual waiver of lien rights, and a notice of request for release of the lien to the claimant at the claimant's address stated in the lien affidavit; and

(2) the lien claimant does not release the filed lien affidavit on or before the 14th day after the date the owner or the original contractor sends the items required by Subdivision (1).

(c) Subsection (a)(3) does not apply to a person who supplies only material, and not labor, for the construction, remodel, or repair of a single-family house, townhouse, or duplex or for land development related to a single-family house, townhouse, or duplex.