Generally, it's safe to assume when someone does work on a construction project, that person will expect to be paid. How soon that obligation to pay arises, however, is likely determined by the contract between the parties. In some cases, when it comes to a prime contractor paying its subcontractors, that obligation might never arise.
The construction business inherently involves a lot of uncertainty and trust. Just to get a job done you have to trust you've hired the right contractor, trust that contractor to hire the right subcontractors, and also trust that those subcontractors are doing satisfactory work. There's simply not enough time to supervise every aspect of the job for yourself. If you've had a construction lien filed against your property, however, you know there is one aspect of the job you should not pass off.