For example, if you need only roofing or plumbing work, you may want to hire a contractor licensed in that particular specialty. A general building contractor also may contract for specialty work, but must hold a specialty license for that work or actually have a specialty contractor do the work.ou can verify the license or call (800) 321-CSLB (2752). ALERT Be advised that unlicensed individuals pose a risk to you and your family's financial security if a worker is injured while on your property, your property is damaged, or if the work is incomplete and/or faulty.