How do I protect myself from against liens?

Always obtain a lien affidavit/waiver from your contractor at the time of any payment stating that all subcontractors (including suppliers of material used to improve the property) have been paid in full and that the contractor waives all lien rights for work done up to that point in time. If you receive a notice from a subcontractor of a claim of lien, do not pay any funds to the contractor until you have met with an attorney to determine your rights.