We have paid our contractor in full, however he is trying to collect an additional $4,000.00 from us for an additional project which was never agreed to and there is no documents supporting this. He now is saying he is going to put a mechanics lien on our house. We believe he has no leg to stand on and has no intention of filing the lien in court. We do not want our credit ruined in the meantime, so we are going to offer to split the difference with him. Is this a smart idea and if so, what type of document can I draw up to have him sign and be assured he does not take this further?