How to Smoke Test the PVC Drains to Find a Leak

A PVC pipe can develop a crack or break over its lifetime. To test whether a PVC pipe used for drainage has lost its integrity, you can use smoke to test for damage. Since the smoke will be seen exiting the pipe at the crack, the area that must be repaired or replaced can be ascertained. An industrial vacuum cleaner (also known as a wet/dry vac) will be needed (and can be rented from select home and garden supply centers), as will supplies from a hardware store or party supply shop.

Step 1

Place the industrial vacuum cleaner next to the drain that connects to the PVC pipe. Plug the vacuum’s power cord into a power outlet.

Step 2

Put on work gloves. Place a chunk of dry ice next to or over the drain hole. If water condensation is a concern, place a piece of plastic tarp next to the drain hole and the dry ice on the tarp.

Step 3

Switch the vacuum’s suction switch to “Expel” -- the word used here may vary depending on the manufacturer, but it refers to the vacuum expelling air, rather than suctioning it in.

Step 4

Aim the hose of the vacuum at the dry ice at an angle that will carry its fumes into the hole. Turn on the vacuum cleaner.

Step 5

Hold the hose so the fumes from the dry ice are forced into the drain hole. Watch the PVC pipe to see if any fumes emerge along its length. If fumes emerge, there is a leak in the pipe. Repair or replace the PVC pipe.