I hired a contractor to prep and pour a mono slab for a precut garage which will be built and erected by a another company. He could never come up with an estimate so verbally we agreed on time and materials arrangement. The pad is completed but the garage won’t be erected until a month. He wants payment of his last bill but I want to hold it back until the garage gets erected. I want him around to address any issues that may arise at the time the garage is going up. We never had a contract. Nothing was in writing. Now he is threatening to put a lien on my house. Without a contract or anything in writing would that be enforceable?