During rough-in, which task is required before drywall is installed?

During rough-in, which task is required before drywall is installed?

• A. Test the water distribution and sanitary drainage systems
• B. Install fixtures
• C. Paint walls
• D. Install gas lines

Answer: (A)

Testing the water distribution and sanitary drainage systems before the walls go up ensures leaks are found while the piping is still accessible. During rough-in, you want to confirm that all supply lines are watertight and that the drainage system holds pressure without leaks, which helps catch problems before the walls are closed in. This step often involves a pressure test for the water lines and a hydrostatic or air test for the drains, checking for proper flow, trap seals, and venting. If a leak or misfit is found after drywall, it becomes much harder and more costly to fix. The other tasks listed—installing fixtures, painting walls, or installing gas lines—are typically done later in the process, after walls are finished or through separate safety procedures, so they aren’t part of the rough-in testing necessary before drywall.

Testing the water distribution and sanitary drainage systems before the walls go up ensures leaks are found while the piping is still accessible. During rough-in, you want to confirm that all supply lines are watertight and that the drainage system holds pressure without leaks, which helps catch problems before the walls are closed in. This step often involves a pressure test for the water lines and a hydrostatic or air test for the drains, checking for proper flow, trap seals, and venting. If a leak or misfit is found after drywall, it becomes much harder and more costly to fix. The other tasks listed—installing fixtures, painting walls, or installing gas lines—are typically done later in the process, after walls are finished or through separate safety procedures, so they aren’t part of the rough-in testing necessary before drywall.