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DIY Tales: Locating a Bathroom Leak

By AZ DIY Guy's Projects on Apr 13, 2014


When I returned home from Jack's karate lesson, Sweetie told me I needed to check the toilet in the guest bathroom. It sounded like it was constantly running. I'd just replaced the valve in the master a couple weeks ago, so I figured it must be time to replace the other one. BUT, when I popped the tank open, I realized the sound was not coming from the toilet, but from a couple feet to the right... in the bathtub... but there was no water dripping. Uh-oh.
I could hear something inside the wall. Note: This phenomenon, is generally what we like to call in the homeowner business, "bad news". Rarely, do noises in the walls turn out to be the shifting of gold doubloons sliding off a big bundle $20 bills onto a pile of 30 year old Apple Computer stock. No, it usually means you are going to spend money, lots of it. It is, however, a perfect opportunity to practice up on your curse words.

With the shower valve opening too small, I couldn't see into the wall, but I could hear water spraying. With the crud-circle buildup around the valve cover as a guide, I cut the hole larger with a rotary tool. The fumes and dust of cutting fiberglass were pretty strong, so I opened a window, turned on the exhaust fan, and slipped into the manly-pink 3M Professional Multi-Purpose Respirator I'd bought for attic work.

cutting into a shower wall with a rotary tool and a 3M respirator
"No Luke, I am your Father" - D. Vader

The leak wasn't in the valve. It was about 8" to the right. I couldn't see directly, but I could see water droplets beading up along the bottom of a 1/2" copper pipe. I could feel a mist and wet insulation when I stuck my fingers in the new hole.

I don't see any hidden treasure either.

Just like plumbers have done for hundreds of years, I stuck my smartphone up to the hole and took a flash photo for a better look.

Fact: This age-old smartphone trick is believed to first been used in Boston, circa 1771.

- The More You Know

I could now see the leak. How the heck to fix this? There's a fine mist of water spraying, away from me, out the back of a 90 degree elbow, behind the wall of a one-piece shower / tub unit. Sure, this yellowing, beat-up old tub is on the eventual replace list, but there's no time or money for that now. I surely can't carve a hole through it and shut down one of our bathing locations.

A plumbing leak, inside the wall.
The culprit.

I checked the other side of the wall, our master bathroom. Now folks, correct me if I'm wrong, but when you press on a wall, it shouldn't bend right? Even if it's over an absolutely hideous 1970's gold marbled counter top?

Wasn't there a bending wall scene in Poltergeist?

The side piece of the back splash (side splash (?)) is a separate piece. I figured I could cut the caulk, remove it, cut a hole in the drywall behind it, and if the DIY gods smiled upon me this day, quickly repair the issue.

Of course, that was before I simply plunged my knife through the caulk and spongy, wet drywall with ease. I slid the blade through the wall, like it was oatmeal.

This is not the work of a Sheetrock saw, just a simple pocketknife blade.

Fan-freaking-tastic! My Facebook followers have already seen my happy face, bright-eyed with the magical wonder that is a handful of sopping insulation and the joy of beholding of drywall unable to hold its structural integrity. It's a face from the musty, recognizable smell, the smell of my weekend evaporating and my wallet flying open.


Can't you just see the joy on my face?

With the wall open, and the insulation out of the way, I was greeted by a effervescent mist of water, steadily wetting the inside of our walls and soaking the floor of the cavity.


Cool mist.

I could feel a J-nail holding the pipe, tight against the 2 x 4 cross-member that was there simply to secure the plumbing. The wood was blocking any hope of repair, so it got hacked out with a Reciprocating Saw.


Since we still had a load of laundry on rinse cycle, I didn't want to kill the water to the house quite yet. A gob of duct tape (the crowning achievement of modern civilization) and did a hasty wrap job, keeping the water from spraying in my face. A bucket placed below, began to collect the dripping water.


The bucket filled in 20 minutes. I figure there was at least 5 hours of leaking water so there is a minimum of 15 buckets of water loose in the cavity. Spec-freaking-tacular!

At least it was a small bucket.

A few years ago, I'd bought a Bernzomatic Trigger Start Torch kit. I use the case to keep all manner of plumbing stuff in one place. I lugged it into the bathroom to see what I had to work with.

Sure it's a nice torch kit, but can you take your eyes off that delicious 1970's counter top?

After shutting water off to the whole house, I used a Mini Tubing Cutter from my kit to slice the section out. These are handy little tools. They simply slide over the pipe and twist around it. You tighten the knob every few rotations, which drives the cutting wheel deeper into the pipe, until it finally snaps off, clean and straight.


It's a handy little gadget. This one really needs a replacement cutter wheel, but it made the two cuts.


Next up! Off to the friendly neighborhood hardware store to buy some copper.


This is running long, so I'll break it off here and tackle the repair next time. The bathroom window is open, there's a fan down in the wall and another one on the counter top. This mess needs to get dried out before the wall can be sealed up.

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