Help! Tiled wetroom floor looks perfect but grout doesn't dry out! - Tile Advice

[Paula]

Well, the tanking is meant to fall into the trap/drain. So the tiles then just become aesthetics to make it all look nice and easy to clean. They're not there stopping water getting anywhere sort of thing.

So it's usually okay for tiles to have cement-based grout, it get wet, water get behind the tiles and soak a bit into the cement-based adhesive, because the water that collects will fall into the drain, and the remaining water behind the tiles would disperse and dry out via the grout generally across the whole floor.

You'd get wet / darker grout using the shower, and a hour or so after, it'd dry out. Wouldn't stay patchy, but might be a bit patchy during drying out etc.

The epoxy has perhaps if anything stopped a bit of that and is pushing the moisture further into the bathroom maybe.

But the fact you're getting droplets of water and it's in quite a few grout lines, but then not others right next to it, would suggest as Deano's said, it's fresh water that's quickly gathering, and taking ages to dry out.

So I'm not sure what's going on around the drain. But it's okay for water to get there usually, as the drain would get rid of it (gravity) and the rest would disperse into the floor generally and evaporate once it's (evenly) reached the surface of the grout. But I've never seen droplets like the earlier images.

I don't think I've still answered you lol sorry. I just don't know what to say about it.

I'm with deano though, I'd have pulled a tile or two up around the drain by now.

JUST A THOUGHT.....


I'm loathe to do that as that will probably damage the membrane. From what you are saying, I just wonder whether the problem is arising with the shape of the shower tray? If you are now saying that it is normal for water to get under the tiles around the drain (I thought before everyone said that this shouldn't happen unless the adhesive was spread unevenly and there were lots of gaps?), but that is OK as gravity will cause it to fall into the drain down the slope, then maybe our slope is not steep enough?

That may have lead to more 'pooling' of water under the tiles than would normally be expected, and therefore it would take much longer for the water to evaporate through the grout, leading to permanent damp patches (which is what we had pre-epoxy). Now we have stopped evaporation through the epoxy, the water is just migrating to where there is normal grout, through which it can evaporate (this is how plants move water from their roots to their leaves, as evaporation takes place through pores in the leaves and leads to a difference in water potential from leaf to root, hence flow of water). So that's why we have damp patches beyond the shower tray.

How would I find out if anyone else has had this problem with an Impey tray? When I originally spoke to them, they said that I should not have any permanently wet patches and that it was a tiling problem!

 

[The D]

It is NOT ok to have water under the tiles it's a problem

 

[Dan]

If you have cement-based adhesive, and cement-based grout, and have tiled to a former, that runs into a trap, and you use a shower, you have water behind the tiles. As it's getting through the grout. That isn't water PROOF, just doesn't break down with water.

So it's going to fall into the trap.

Right?

Am I missing something?

 

[The D]

yes lots

 

[Dan]

Oh right.

Sort of renders tanking useless then if the tiles are the water barrier eh?

@Paula, listen to @deanotile, he's the tiler out of the two of us.

I don't want to tarnish the thread with a bad tone or anything so I'll stay out of it if I'm giving the wrong advice.

 

[The D]

tanking is a failsafe so that if there is a problem the water is contained and the background is not damaged the primary waterproofing is the tiling.

 

[Dan]

You're misunderstanding the word 'waterproof' if you think a tiled wall or floor is impervious to water, surely?

EVERY bathroom wall that's not tanked, fails eventually due to the substrate getting wet constantly when it hasn't been tanked. EVERY bathroom wall that's been tanked, and properly using tape onto the bath or shower tray, NEVER fails due to water ingress.

So the tiles are literally never protecting the substrate from water and are literally just there to take the brunt of the 'weathering' (term used loosely) and cleaning and to give the room an aesthetically pleasing look.

Not meant to come across argumentative BTW.

 

[The D]

if the job is done right the background should never get wet not even damp

 

[The D]

dan i have striped tiles that have been on commercial showers for twenty years and the background has never seen a drop of water and as a professional tiler i am telling you that the tiling is the primary waterproofing and the tanking is a secondary failsafe


this misconception of grout letting water pass through it like it's not there is just silly. if the grout is constantly submerged in water for long periods of time like months at a time then eventually the water will penetrate the grout and possibly come in contact with the background. but in a domesick shower with intermittent wetting the water will not fully penetrate the grout unless there are other problems such as cracks or pin holes

 

[Dan]

If you ask BAL technical which dispersion adhesive to use, they'll explain intermittent wetting will not affect their blue star, but regular wetting will (might be wrong on the colour, and I'm sure they don't make that even now?). So they're expecting water to get through. And they're celebrating 50 years of being a "leading brand" this year. So my email today said.

Formers are shaped to allow water to flow down to a trap.

Tanking is designed to allow water to fall into the bath.

There are umpteen products that are not just designed as a backup. They're literally designed to take the water somewhere. As the guys in the white suits know water IS getting through that cement, that's NOT going to stop it.

I appreciate you taking more time to write something decent in the thread though. And perhaps this subject is a matter for a different thread.

But water IS getting behind the tiles here. And due to the amount, I'd say its not just from use. It's from a pipe. The former and the trap are perhaps not doing their job in this case. But maybe they are and it's something else.

 

[Paula]

If you ask BAL technical which dispersion adhesive to use, they'll explain intermittent wetting will not affect their blue star, but regular wetting will (might be wrong on the colour, and I'm sure they don't make that even now?). So they're expecting water to get through. And they're celebrating 50 years of being a "leading brand" this year. So my email today said.

Formers are shaped to allow water to flow down to a trap.

Tanking is designed to allow water to fall into the bath.

There are umpteen products that are not just designed as a backup. They're literally designed to take the water somewhere. As the guys in the white suits know water IS getting through that cement, that's NOT going to stop it.

I appreciate you taking more time to write something decent in the thread though. And perhaps this subject is a matter for a different thread.

But water IS getting behind the tiles here. And due to the amount, I'd say its not just from use. It's from a pipe. The former and the trap are perhaps not doing their job in this case. But maybe they are and it's something else.

Goodness, we seem to have opened up a can of worms here!

It does seem that there is an awful lot of confusion about the roles played by tiles, grout, adhesive and tanking, even among professionals with many years of experience in the industry, so I'm not surprised that it is taking me so long to sort this problem out! I just thought I would try and recap where I think we have got to.....

I had sort of resigned myself to accepting that some water would always get under the tiles while showering, as I had gathered from literature/the BAL rep/forum discussions that cementitious grout is only water-resistant, not water-proof. I would imagine that porcelain tiles are pretty waterproof, so can't imagine much water would be getting through them. However, if this is the case, then why are there not more complaints on the forum of grout never drying out in tiled shower trays? It would seem that there is something different going on in our tray, which could be any of or a combination of these situations:

- more water entering behind the tiles from a leak in plumbing pipework to the shower heads
- large gaps in the grout in the tray leading to excessive ingress of water
- large gaps in the adhesive under the tiles so that water can 'pool' here, without falling down the drain

It seems unlikely that water is getting in from the drain, as this would eventually get through the membrane and on to the ceiling below, which is not happening.

What has been odd is that, having taken out the cementitious grout in the tray, and replaced it with epoxy, which is far more water-resistant, we now have dampness appearing away from the areas which get wet. WE HAVE NOT USED THE SHOWER FOR 4 WEEKS NOW AND THE GROUT OUTSIDE THE TRAY IS STILL DAMP IN PATCHES!

Thanks to all the useful discussion on this thread, it seems that this could either be because water is STILL getting through the tiling in the tray, even when the shower is not in use (from constantly leaking plumbing) OR perhaps because there is water trapped under the tiles and new epoxy grout in the tray, and this is now trying to escape through evaporation across the rest of the floor.

Having seen the results of pressure tests on the shower pipework, and never having seen any dampness on the walls (or, more likely,the ceilings below as our walls are only tanked at the bottom) I would be inclined to discount plumbing issues.

So, that leaves us with the possibility that there is still water under the tray tiles, even after 4 weeks. It could even be possible that this water dates back to the pre-epoxy days, even though we did not use the shower then for about 12 weeks, as even at this stage, we still had damp patches in the shower tray. I am told that it could take up to 6 months for dampness behind tiles to dry out! Now that we have re-grouted with epoxy, this is not helping to disperse any remaining dampness as it cannot escape easily through the epoxy, so it may be trying to escape through the adhesive bed and up through the cementitious grout on the rest of the floor.

We're sort of in limbo, as we feel that we can't do any more testing until we have a completely dry floor. Underfloor heating last week helped to dry the patches a bit, but they reappeared as soon as we switched it off, although they are diminishing slightly overall. If it gets to the stage that they are almost gone, then perhaps we should try re-using the shower, and if they return, we know that water is definitely getting in through the top of the tiling, through the epoxy.

I don't think we can do anything else at this stage.

 

[Dan]

Thanks for the update.

Water can't disperse through epoxy at all. It's impervious to water, bleach, even sulphuric acid, apparently.

I hope you get to the bottom of this. I'd be pulling tiles up by now myself to find the source of the water.

 

[WetSaw]

Just reread your post... No more to add, sorry!

 

[Paula]

Just reread your post... No more to add, sorry!

Thanks! Just thought it was worth re-capping, just in case anyone had any further thoughts or knew of other situations like this.

I'll let you know how we get on!

 

[cbmltd]

I've seen something like this before with mapei plus grout the bottom row on top of the wet floor had been doted and therefor the grout had failed the water was seeping behide the wall tile and under the mosaic wetdeck.
After a week of drying out,removing the base tile,tiling it properly and using an epoxy grout over the whole area.well I haven't been called back .i think the repair was a succes.