(1) A written waiver of construction lien rights signed by a claimant requires no consideration and is valid and binding, whether signed before or after the materials or services were contracted for or furnished. Ambiguities in a written waiver are construed against the claimant.
(2) A written waiver waives all construction lien rights of the claimant as to the improvement to which the waiver relates unless the waiver is specifically limited to a particular lien right or a particular portion of the services or materials furnished.
(3) A waiver of lien rights does not affect any contract rights of the claimant otherwise existing.
(4) Acceptance of a promissory note or other evidence of debt is not a waiver of lien rights unless the note or other instrument expressly so declares.