Need to hold extra-wide work for gluing up or driving screws? You can hook one jaw of a pipe clamp over your work, then turn the opposite jaw 90 degrees so it lays flat on the work. Hook a second pipe clamp to this jaw, and at the other end turn that jaw 90 degrees and tighten. If two clamps won't reach, just add a third clamp between the first two.
Contact your local building inspection department to check for permit and inspection requirements. Be wary if your contractor asks you to get the permit. It could mean the firm is not licensed.