Why is water coming out of the grout on the side of our Shower?


Hi, recently we have noticed water coming out of the grout on the side of our shower where the wall and the floor meets. After not using the shower for a few days we noticed that area never dried... so we placed a towel there with pressure to draw out the water. We also notice a lot of darker color grout at random areas (but not wet) --- we have noticed the discoloration since the tiles were newly installed 3 years ago.

Wee have cut open the wall to check for pipes/plumbing and those are fine. And no wetness behind that wall.

I can't make sense out of this how can water be trapped underneath the tile and come out of the grout??? Does it mean the mortar is saturated? I don't notice any drainage issue and the shower floor is never soaked in water so we can't figure out where all this water are coming from... The grout seems to be failing (getting sticky) and I am not sure if that's the cause of the problem, or a result from the problem. Any idea what the problem might be or what else we can do?

Here's a photo of where we first noticed water issue:

Thank you


ANSWER - From your photo the bottom edge of the wall tile where it is adjacent to the transition joint from the wall to the floor has efflorescence staining.  That suggests water is traveling from behind the tile and evaporating through that joint.

I also notice that transition joint has a crack or tear.  Can't tell if the joint has a silicone or polyurethane sealant in that joint as it should.  If it is cementitious grout in that joint it should not have been used there.  It should be filled with an ASTM C920 sealant over a foam backer rod.  If there is a caulking there and it teared, it is probably because the sealant doesn't meet ASTM C920 and/or it wasn't installed correctly.

Since the wetness is at the perimeter of the shower floor adjacent to the wall tile joint that has a crack and has efflorescence staining, I would guess that water is getting to the back of the tiles through the tile grout joints and it travels down to the bottom of the wall where it comes out.  It is not unusual for water to penetrate into the grout joints, but perhaps there are excessive voids behind the tiles.  Industry standards say you can't have more than 5% voids behind a tile that 5% should be dispersed.  If you have a lot of voids behind the tiles the water readily travels behind the tile and can collect at the bottom. The water apparently isn't getting into the wall cavity, which is a good thing, but rather traveling between the back of the tile and the substrate to which it is attached.

4 thoughts on “Why is water coming out of the grout on the side of our Shower?

  1. Peter Yip says:

    Due to recent rain in Singapore, I have encountered that water seeps out from the grout line at the Basement Lobby from of the marble slab. I also noted the the installer are using chemical adhesive to bind the marble slabs.
    The other reason I could reason it is that the water table is too high causing saturated water coming out from the grout line.
    May i source any solution to it.
    Thank you.

    • Donato Pompo says:

      I’m not sure what you mean by the installers used a chemical adhesive to bind the marble slabs. Perhaps they are using an epoxy to adhere them to the substrate or they are using it to adhere adjacent slabs to each other?

      That should not have anything to do with the water seeping out from the grout joints.

      Apparently the water seeps from the grout joints only when it rains. So that either means the water table rises or that water is traveling from a high area down towards the building where the travels under the building and then maybe through hydrostatic pressure the water is forced up through the grout joints.

      If it is the water table that is an expensive process to remediate. You would have to build some sort of underground cistern and then pump the water out to keep it from the floor.

      If the water is coming from draining down to the building from a higher level then you can dig trenches around the perimeter of the building and put a perforated pipe in with a sock over it covered with gravel and then have the water drain away to a storm drain.

  2. Stacy says:

    Apparently the shower is leaking through the tiles and dripping out of the ceiling in the basement – it is not coming from the pipes. I noticed some of the caulking is missing so there is a space there. Can you just recaulk the tiles? My friend suggested possible a shower insert. Any suggestion would be greatly appreciated.

    • Donato Pompo says:

      If the shower is leaking to the extent that it is dripping out of the ceiling of the basement the problem is that either the shower pan was installed wrong or the waterproofing has failed for some reason. It is unlikely that replacing the caulking will fix the problem. Although you can try to replace the caulking with an ASTM C920 sealant and hope it works.

      Depending on the configuration of your shower it might be possible to install a fiberglass shower pan over the existing shower pan, but would have to be sealed well and isn’t likely to look good.

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