what determines a subcontract in Tx

I am a subcontractor in Texas and will start a job for a general contractor then find I need protection to ensure that I have the job for the duration of the project. Most builders are reluctant to work on a contract basis for my speciality which is bathtub repair. They will have me start on a project and oftentimes later forget that I am even doing the work. The problem is that they will later forget and hire someone else to do the same work after I started the job orginally. Is there any point in pursuing the issue as a verbal agreed contract ? Is there any protection at all if I do not have a written contract?

Not unless you want to spend all your time in SCC.