Once the material is attached to the building, it no longer belongs to the plumber, if he tries to remove it, he could be charged with trespassing at the minimum and theft (ironic ain't it) at the maximum.
It is the property owners responsibility to pay the plumber. The plumber should protect his rights by placing a lien on the property. The property owner must pay the plumber, even if the general contractor has alredy been paid for the job. This is why it is important for property owners to obtain waivers of lien from all persons involved in a construction project.
Of course, this just applies in the Mountain State.
Tom
