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Old 09-08-2008, 02:13 PM
Join Date: Aug 2003
Location: slightly north of center
Posts: 4,610
Leaking shower floor - ideas on how to fix it

We've got an upstairs shower who's floor is leaking. We looked at it, and a plumber looked at it, and the leak is definately through the floor, not the walls, pipes or drain.

It's on the second floor, a tiled shower. Our best guess is that there is a crack in the under layers someplace. Unfortunately, the stall size isn't a standard size, it's about 23"x23", so we've been unable to find a standard shower pan that we could just drop into place.

Is there any way to put a layer over the existing floor, without having to rip out the current tiled walls or floor?
Old 09-08-2008, 04:48 PM
Charter Member
Join Date: Mar 1999
Location: San Francisco area
Posts: 16,182
Not anything that would actually last more than a couple of days.

The proper repair, sadly, will be labor-intensive. At a minimum, you'll want to remove the shower floor and up the walls about a foot or so. Replace whatever wood is rotting, then rebuild the shower. This page gives an outline of what's involved with mortar and rubber membranes to make a waterproof shower pan.

Plan B would be to remodel the bathroom and change the shower so a prefab unit will fit. As a do-it-yourself project, this actually might be easier. Of course, you'll still need to address any possible structural damage caused by the water.

Last edited by gotpasswords; 09-08-2008 at 04:48 PM.
Old 09-08-2008, 05:11 PM
Join Date: Oct 1999
Location: San Diego, CA, USA
Posts: 1,807
We had a similar problem with our upstairs shower, but in our case, it was the seal around the shower pan that had broken and water was dripping down the sides of the wall and through those breaks in the seal. The solution was a quick trip to Home Depot and purchase of some clear silicone sealant. We just let the shower dry, put it on, and used the other shower the next morning to let it set.

It's not clear to me with my limited knowledge of home repair where exactly your problem lies, but if it was me, I would find the source of the leak, make sure the shower is totally dry, use some kind of super hardcore glue on any tiles (Sumo Glue - also at any home store is my preferred choice), and then I'd silicon seal the crap out of it around any edges. Not pretty, but pretty damn cheap.
Old 09-08-2008, 05:59 PM
Join Date: Aug 2003
Location: slightly north of center
Posts: 4,610
We're looking at remodeling a different bathroom to make it handicap accessible, which would include a shower that has a pan level with the floor. I'd been hoping that we could get something similar and just fit it in over the existing floor, and seal up the sides. I contacted the manufacturer, but they don't make anything as small as I need for this first shower. Imagine that. Not many 23"x23" handicap showers called for.

We've poked at this from the bottom as well as the top (thankfully, it's easy access from the first floor) and between us and a plumber, it looks like the original pan or membrane is compromised somehow. The good news is, from below, the flooring under the shower doesn't seem to be rotting at all. Some waterstaining, but no rot.

Thanks for the link gotpasswords. Looks like that will be some fodder for dinner conversation.
Old 09-08-2008, 06:08 PM
Join Date: Jul 2001
Location: Portland, O-bamagon
Posts: 7,851
We had similar problem and I put silicone grout where the corners of the wall met, as well as all along the edge of the floor and wall.
Old 09-08-2008, 06:16 PM
Charter Member
Join Date: Mar 1999
Location: Anderson, IN,USA
Posts: 14,741
Here are two more details to consider, when contemplating major bathroom work.

Are there any other jobs that might go easier when the bathroom is torn apart? A month after one bathroom job, we wanted to put porch lights on opposite sides of the porch. To get it done, we would have had to tear apart one of the freshly papered walls in the bathroom.

Even if the toilet is not part of the job, pull the toilet and replace the wax seal. Dead wax seals announce themselves as rotten floors, which are really expensive. Wax seals are cheap.
When I make a To-Do list, the first item is "Make a list." That way, I can cross one item off right away.
Old 09-09-2008, 12:20 AM
Join Date: Feb 2004
Location: the Prairie
Posts: 6,771
In days gone by (and maybe still today), a thin lead liner would be placed under the tile, etc., which could be fitted to any size shower.

23" x 23"? I think I would have continually bruised elbows.

Any chance you could enlarge the scope of the project?
Old 09-09-2008, 03:11 PM
Join Date: Aug 2003
Location: slightly north of center
Posts: 4,610
Originally Posted by Oslo Ostragoth View Post
23" x 23"? I think I would have continually bruised elbows.

Any chance you could enlarge the scope of the project?
That shower makes me claustophobic. While we have long term plans to rearrange the bathroom, right now there are a couple of other large projects that need to be done first. But while we are dealing with a total redo of one end of the house, for an in-law suite, it would be kind of nice to have a shower, even if a small one, available.

Wish us luck. It looks like we can, by removing the lowest tier of wall tiles, squeek out a 24"x24" floor. I've seen 24"x24" shower pans advertised, so hopefully, if that really is the external dimensions, we can put in a new pan over the existing floor, redo the drain, caulk the hell out of the edges and have a non-dripping shower that will get us through the next year or so.
Old 09-09-2008, 04:19 PM
Join Date: Aug 2000
Location: Small blue-green planet
Posts: 1,381
For what it's worth, we have had a shower repaired by putting a new (sheet vinyl) pan over the old tiles, then installing a new layer of thinset, tile and grout on top of the new pan, and then replumbing the drain. It was done about three years ago, and so far, no trouble. This appears to be a fairly common repair where I live, where many of the houses are 50+ years old, and shower floors are starting to deteriorate.

Last edited by Running with Scissors; 09-09-2008 at 04:20 PM.

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