View Full Version : leaking tiled shower

04-26-2007, 07:41 PM
The floor and the walls of our shower are tiled. The valve and lever (Delta Monitor) are on a wall shared with the living room . The shower head is on a perpendicular wall and is also shared with the living room. I noticed water marks on the wooden living room floor. I removed the coverplate from the valve and shower head, wrapped paper towels around any accessible pipe joints and opened the valve to cold and hot and NO dampness was found on the towels. Our house is 8-yrs old and is built on a slab and there is no access panel. I would have to tear out the living room wall to see the pipes beyond the joints which are visible through the holes cut in the shower tile. I checked the tile grout joints and found missing grout around the floor drain and a few 1/4 inch areas of missing grout on the wall. Is it likely this could have caused an area of discoloration in the wood 1 foot by 5 ft long? I regrouted the entire shower in the hopes of curing the problem. I went in search of a moisture meter to compare before- and after-repair dampness, but they don't sell them locally and the online models are very expensive. How can I tell if I fixed the problem short of waiting to see if the living room floor rots? What next? You need to add a praying hands icon.

04-26-2007, 07:59 PM
First of all, grout is not waterproof. Neither is tile, for that matter. What makes it waterproof is the membrane that is underneath. Since the house is only 8 yrs old, I'm kinda thinking that the membrane is not the issue. Can you isolate the leak at all? Does it happen with just the shower running? Is it only with the hot, but not the cold, or vice versa? Perhaps it is the drain......
Can you see anything from underneath, or are you on a slab?

04-26-2007, 08:44 PM
If I had to guess, there is probably no waterproof liner in your shower. Some people that build showers seem to think that a shower on a slab doesn't require one. As was mentioned, grout isn't waterproof, (well, maybe an epoxy one) and will allow moisture to pass through it (slowly). If the shower is used often, it may not have a chance to dry out in between, and eventually, you have a good accumulation of water under the tile - with no liner, it eventually ends up going somewhere where it shouldn't be.

Keeping the grout intact slows this down. Sealing helps a little with moisture, but it is more for stain suppression.

If it doesn't have a liner, other than limiting the opportunities for moisture intrusion by keeping the grout intact, the only fix is at least a partial tearout and rebuild.

Check out www.johnbridge.com (http://www.johnbridge.com) .

04-27-2007, 07:02 AM
The actual leak is not visible (no visible water) except for the stain on the wooden LR floor. The house is on a slab and we have been living here for nearly 2 of the 8 years the house has been in existence. Regarding the liner, the builder has a good reputation, but I have my doubts. The hot and cold water supply are reversed in the shower and we had backup sewer problems when we first moved in. The camera found a 1/2 inch thick rubber disc partially blocking the 4 in outlet to the main line...plumber said it was a temporary cover used by the builder that somehow ended up in the line. (Sabotage or stupidity?) Is there any way to see the rubber shower liner without tearing out the tile? Is the liner only on the floor of the shower? or does it go up the walls? When I remover the valve/lever cover I see only wallboard and grey cement-like material which I assume is mud between the tile and the wallboard. I read something online about prepping the tile and grout with muriatic acid and then applying a sealer. Could the muriatic acid remove the finish on the shiny wall tile? What sealer is recommended for white tile and white grout? Would like to avoid yellowing is possible.

04-27-2007, 07:44 AM
A liner normally only covers the bottom, goes over the curb, and up the walls maybe a couple of inches above the curb. To see if there is one, you'd have to open the wall down low, and even then, you might not see if since to support it, they usually put blocking between the studs to help hold it in place.

The best place to get advice on a tiled shower really is www.johnbridge.com.

04-27-2007, 10:01 AM
Yup. What he said.......
Before you get too far ahead of yourself, just try to investigate some simpler things first. Is there another shower you could use for a couple weeks to see if the spot dries up? If you don't use the shower, and the spot remains wet (or continues to grow) it could mean a supply line has a leak. Since you you could see the faucet and found no drips, chances are everything from the faucet up to the shower head is OK. So it could be a supply line, or the drain.
Would it really be that big of a deal to open up the wall in the living room? All it takes a hole, down low, a few inches from the floor. Just big enoung to put your face, and a flashlight in. If the liner has failed, or a pipe, you will know it immediately from the presence of moisture and mold.
Last but not least, you could have a slab leak. Grrrrrrrrrrr...let's hope not.

05-10-2007, 06:16 AM
Thanks for all the help. Finally called a plumber. He informed me that it could not possibly be a pan leak because the shower is sunken and below the floor level. I did a good job of troubleshooting but we have a slab leak. GRRRRRR as you said. Never had a home with a slab and never dreamed such a thing could happen. Prefer a wet basement...could fix the problem myself.

05-10-2007, 04:26 PM
Glad you got to the bottom of it. NOT glad it was a slab leak. Your plumber is going to suggest a repipe, and if you can afford it right now, you should really consider doing it.