Smelly shower pan options

[Larbo]

A few years ago we had the pan replaced and the bottom half of the shower re-tiled. A hole had apparently opened up unnoticed in the corner of the floor (broken grout) and, along with now there is a constant suphur'y smell coming from it. Besides fixing the grout, should I treat this somehow (for smell, health and pan integrity concerns)? How would I do that?

BTW- Instead of a mopped pan, this contractor installed a "cutting edge" German rubber/neoprene sheet system instead.

I am thinking about drilling a small hole in the floor through the open grout in order to partially drain the collected/smelly water (via small tube and syringe), inject it with hydrogen peroxide, then seal the grout back up. Maybe use a mold proof caulk?

Any suggestions short of replacing the pan would be greatly appreciated.

Thanks, Lar

 

[Jadnashua]

First off, the shower pan should not leak even without tile or grout in place. What should happen to pass a plumbing inspection, is they should plug the drain and fill the pan with water prior to installing the final mud and tile to verify it doesn't leak.

The most common reasons for a shower to smell are:
- improper vent so that it can get sucked dry, letting sewer gasses into the home
- plugged weep holes in the drain, if that type of drain is used
- the waterproofing layer is not sloped to the drain. This is NOT the tile...the tile is a decorative wear surface, not waterproofing.

If the waterproofing is not sloped to the drain, the mud underneath the tile will start to accumulate moisture and, eventually, start to smell like a swamp.

FWIW, California is one of the few places in the USA that tends to use hot mopped...probably mostly because of the cheaper labor. IMHO, it is by no means the best, but can work fine if it is installed properly.

 

[Sponsor]

 

[Larbo]

Thanks for the lengthy reply. The drain does not smell and it seems that broken grout has allowed water to leak under the tile flooring. Do I read right that the drain has an opening under the flooring in order to keep the pan drained? Not that it matters, this pan is not mopped but has some kind of "rubber-ish" sheeting there (I saw it during the installation). Thanks

 

[Jadnashua]

A conventional shower pan drain is what is referred to as a clamping drain. Notice the bolts...the liner is placed under that upper section and sealed to the base. Those small openings are called weepholes, and that lets any moisture that gets down below the tiled surface to work its way through the material there and into the drain. A conventional shower pan expects water beneath the surface, and it's constantly, but somewhat slowly, flowing. That part only truly fully dries out if the shower is not used for an extended time. A common fault is to not install a preslope so that the liner is sloped to the drain as is required by the plumbing code. Often, the inspector, if it was even inspected, only looks for leaks during a flood test, but not for the required slope. If the liner is installed flat on the floor without the preslope, or doesn't treat the area around the drain body properly, the weep holes can get plugged up, retaining water, and eventually, that can start to smell like a swamp. It needs to be able to flow and not stagnate.

Liners like that are not new, but maybe uncommon in CA where cheaper Mexican labor makes a hot mopped pan easier to make more money. A more modern technique is to use a tileable, waterproof membrane directly underneath the tile. That uses a different drain, such as this one.

 

[Larbo]

Thanks for giving me the shower pan lowdown!!!

I cannot say what is going on definatively but it certainly does not seem to be draining (very well, at least). Knowing it may be of temporary beneift, I think I would still like to try to treat the "swamp" water, then caulk it. All can think of is drilling a small hole in the tile floor, syringe out what I can remove and introduce a little hydrogen peroxide.

Is this something no one has ever done before?? Could it work for a while?

 

[Jadnashua]

If the liner wasn't presloped, or if the weepholes are now plugged up, there will be pooling water beneath the tile in the mud bed. By design, that should be continually flushed out by the small amount of water that gets beneath the tile, and flow to the drain.

There's not much you can do about that. You might try buying a drain plug, plugging up the drain, then filling the pan with water...that would fully saturate it, and MAYBE flush a bit of the stagnant water out, or at least dilute it some.

One class I went to, the instructor indicated that 70-80% of tiled showers built in the USA were not done to industry standards. The task is not technically hard, but is very detail oriented. Fail one step, and you can have problems. Making it look pretty is only part of the job, and some just concentrate on that aspect.

My go-to place for tiling stuff is www.johnbridge.com

 

[Jeff H Young]

A conventional shower pan drain is what is referred to as a clamping drain. Notice the bolts...the liner is placed under that upper section and sealed to the base. Those small openings are called weepholes, and that lets any moisture that gets down below the tiled surface to work its way through the material there and into the drain. A conventional shower pan expects water beneath the surface, and it's constantly, but somewhat slowly, flowing. That part only truly fully dries out if the shower is not used for an extended time. A common fault is to not install a preslope so that the liner is sloped to the drain as is required by the plumbing code. Often, the inspector, if it was even inspected, only looks for leaks during a flood test, but not for the required slope. If the liner is installed flat on the floor without the preslope, or doesn't treat the area around the drain body properly, the weep holes can get plugged up, retaining water, and eventually, that can start to smell like a swamp. It needs to be able to flow and not stagnate.

Liners like that are not new, but maybe uncommon in CA where cheaper Mexican labor makes a hot mopped pan easier to make more money. A more modern technique is to use a tileable, waterproof membrane directly underneath the tile. That uses a different drain, such as this one.

I agree with much of this but I dont think hot mopping a shower is cheaper labor than a pvc vinyl pan I think its likely more money around 300 or 350 assuming its completly ready with blocking etc. I dont think floating walls is cheap either it does take skill that many dont have skills for. a liner or a hot map is similar and does have guidlines if not followed might fail in this way due to sloppy work.
I think a cold pan would be cheaper Im sure you could go down to a state like texas or alabama or missisippi I doubt they hot mop for peanuts, In Ca anything other than hot mop is looked down at, I cant say why

 

[Jadnashua]

You can hotmop and put the setting bed down the same day - it's stable as soon as it cools...a traditional deck mud liner means coming back the next day generally...time is money, then coming back the next day to then tile it. Now, depending on the job, you might be able to do other things in the remodel, so it's not wasted time.

Many different systems can work, but they require attention to detail and following industry standards.

There are advantages to using a surface applied, tileable membrane...very little to get and stay wet, and at least with the Schluter system, no VOCs.

 

[Larbo]

One question, with a membrane pan material, is the floor tile typically built right on top of the membrane? Thanks

 

[Jeff H Young]

One question, with a membrane pan material, is the floor tile typically built right on top of the membrane? Thanks

no its not typicaly the drain grate is 2 inches above the sub floor and a sloped pan toward the drain with "weep holes "around it then a mud bed is placed for the the height of grat minus thickness of tile and thinset . perhaps if you look at a shower drain it might help make sure its for a hot mop or a liner or for the type pan your using

 

[Jadnashua]

A conventional shower is made up of five layers:
- preslope
- liner
- setting bed
- thinset
- tile

A topical sheet membrane shower is made up of these layers:
- sloped layer
- waterproof, tileable membrane
- thinset
- tile

The conventional shower has typically about 1.5" of porous deck mud (sand/cement layer) just underneath the thinset and tile. It is expected that the setting bed will become damp, and need to drain to the weepholes. A sheet membrane shower doesn't have weepholes as the thinset is denser, ad usually, whatever moisture may get into the grout, dries out in between showers, so there's not any moisture to weep out. Moisture tries to move to spread out to drier areas, and the deck mud is like a sponge. The Kerdi membrane is hydrophobic, so water is repelled, so most of the time, the moisture that might start to penetrate doesn't get far, so it tends to dry out in between uses. Kerdi is one of a few approved systems to make a truly waterproof shower. Other than the pan, most are all just water repellent.