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I recently replaced a shower tray and now have a leak. This is what I did. Removed old tray and one row of tiles, together with the plasterboard they were stuck to (it's a shower cubicle with walls on 3 sides). Re-boarded the missing board with aquapanel, sealed at the top where it meets the old board, and at the vertical joints. Installed new tray. Aquapanel butts down onto the new tray (new tray has no upstands) and comes forward about a tiles's worth, but only above tray level. Sealed between aquapanel and tray. Tiled down to the tray, grouted, and sealed around the tray again. Refiited the shower doors. Sealed on the outside. Job done ....except ....

Now, after being in the shower for about 5 mins, water starts dripping at the front left corner of the tray. As far as I can tell it's coming from behind the tiles. To support this theory I draped some plastic sheet on the left wall, had two people use the shower and no leaks. The only conclusion I can come to is that water is somehow getting between the tiles and the aquapanel, running down to tray level, then along the tray towards the front. It can't get out because both the aquapanel and tiles are sealed to the tray - I'm imagining it running in a channel towards the front of the shower tray. Then when it gets to the front left corner of the tray it drips over the edge and down to the floor.

So, my questions are. Does this sound at all likely? Is it possible that the water is going through the grouting? There are harline horizontal cracks in the new grout where I assume there's been a bit of settlement but I don't know if it's enough to let water through. If this is the case, how can I fix it? I'm guessing (a) stop water getting through grout if that's possible, and/or (b) have some sort of vertical barrier at the front edge of the tray between the tile and aquapanel.

Thanks for any advice.

Providing the tiles are firmly stuck down and not moving at all then all you need to do is scrape the cracked grout out and re-grout it.

You have only just completed this job and therefore not let the grout cure for long enough before using the shower. That is one option for the leak. Check the instructions for the grout and see how long it tells you to wait before using the shower.

Sealed front of shower doors. Some are seal internally only.

royaloakcarpentry wrote:You have only just completed this job and therefore not let the grout cure for long enough

Sealed front of shower doors. Some are seal internally only.

And some are seal externally only, having internal channels for the water to run back to the shower tray..

Thanks everyone. Still curious about grout in general though. Does all grout let at least some water through? And hairline cracks - would they let a significant amount of water through? (I'm probably talking about an egg cup full over the course of 5 mins)

Grout is not waterproof, rather "Water resistant" and any crack, no matter how small has the potential to cause a leak..

As a matter of interest what tile adhesive did you use ? tubbed/ready mixed or mix yourself?

It is surprising how much water can penetrate a pinhole in grout. I am not sure from your description but did you grout the whole shower or just the new tiles? It really would pay to rake out the grout off the whole shower and do it again. See http://www.ultimatehandyman.org/video/t ... emoval.php 'how to' video. You will need to buy a Bosch PMF but quite frankly every home should have one

DWD

Tubbed/ready mixed adhesive.

I only regrouted around the new tiles. I'm sure it would be worth removing all the old grout, but frankly it seems like a hell of a job and I reckon would take me a day or two with a grout rake - maybe longer, or maybe I'm just slow! Just had a look at the video for the Bosch PMF and whereas it looks like a fantastic tool, I'd be very afraid of damaging the tiles.

mrsparks wrote:Tubbed/ready mixed adhesive.

I only regrouted around the new tiles..

Willing to bet the tubbed adhesive is half the problem.
Using that I would leave a full 48 hour drying time before grouting, then at least 24 hours before going anywhere near the shower..

Sorry to resurrect this thread, but I still have a problem. I regrouted the row above the new tiles (where there was a hairline crack). What I've discovered is that if one person showers, it's OK. If two people shower one after the other (or presumably if one person showered for twice as long) then I start to get a drip from the same place as before - front left corner. One thing I've tried is to hang a bin liner on the left wall while showering. When I do this I get no leaks. So the conclusion I've come to is that some water leaks even when one person showers, but not enough to show, and it's the accumulated effect of of two or more that causes it to show. The bin liner test seems to show that the water's getting through the wall - I presume it has to be getting through the grout. Does this make sense? If so, maybe the only solution is to re-grout the whole wall with waterproof grout. In the meantime, it's a one person per day shower!

what makes you think it's not the seal between tiles and shower screen/enclosure?

Re-grout let it dry out and use seal guard great stuff especially for showers that were installed without tanking. http://www.seal-guard.eu/uk/tile_sealer_aerosol.html

Would I have to regrout in order to apply sealant? Can it be applied to old grout (if I gave it a good clean)?