How to Repair a Leaky PVC Pipe Joint – Part 1

Featured, Plumbing | June 25, 2009 by Bob Jackson | 1 Comment

Had another water stain on the basement ceiling, this time it was a leak in the washing machine PVC drain line. Two leaks on different sides of the room in the same month! Go figure!

Leaking PVC Drain Line from the Washing Machine

I was able to get access to the ceiling crawlspace by setting up a ladder in the closet. Access was awkward, but I was able to reach the pipe with an outstretched arm. I quickly located the leak, a slow drip at the PVC elbow joint in the washing machine drain. The solvent weld joint had partially failed, most likely because of poor workmanship – as I was to discover shortly.

The finished basement has a suspended drywall ceiling. This next photo is the water damage to the drywall ceiling as seen from the crawlspace. I don’t frequent this room in the basement that often, but the leak couldn’t have been happening for more than a month.

Water Damage on the Drywall Ceiling

Fernco Extra Length Qwik Ell Repair Fitting

The 2-inch PVC drain line is solvent welded (permanently glued) together. The correct way to make the repair is to cut out the bad section pipe and/or joints.

I purchased a Fernco 2″ inch QL-200 Qwik Ell at Home Depot to replace the PVC elbow. The Fernco Qwik Ell “extra length fittings” are perfect for this job. The “extra length” is necessary because the flanges of the PVC pipe elbow will be cut out, leaving a larger gap than normal. The Fernco fitting accounts for the extra gap as shown here compared to a standard 90° PVC elbow.

PVC Elbow compared to the Fernco Qwik Ell QL-200

Another view of the Fernco QL-200 with a vernier caliper.

Vernier Caliper and Fernco Qwik Ell QL-200

Cutting out a section of PVC pipe to make a repair is a significant decision. You only get once chance to make the proper cuts or you’ll mess up big time $$$. I used calipers to measure the diameter of the 45 degree PVC elbow just below the glue joint where I’d be cutting the pipe because I wanted to reassure myself the Fernco Qwik Ell would fit.

Measuring the PVC Pipe with Vernier Calipers

I compared the diameter of the PVC pipe joint with the inside diameter of the Fernco Qwik Ell to confirm the fitting matched the PVC elbow. No surprise – if matched almost perfectly, just a bit on the small side as it should be for a tight fit. I just wanted to be extra sure.

Verifying the Inside Diameter of the Fernco Quik Ell

Make a Cardboard Template

To mark the positions of the cuts on the leaking PVC pipe, I traced the outline of the Fernco fitting on a piece of cardboard. I needed to do this because there was no space between the PVC drain pipe and the floor joist to position the Fernco fitting directly to mark my cuts on the PVC pipe.

Tracing a Cardboard Template of the Fernco Qwik Ell

This is the cardboard template compared to the Fernco Qwik Ell. The important dimension are the lines marking the position of the shoulders at each end.