Tiles falling off - new build

[TedStriker71]

Hi,
Just wanted to get an idea of what could have caused this so we know how to proceed with the builder. We've had a leak in our shower (new build, 1 year old), showing up as a damp patch on the 'other' side of the wall from the shower enclosure. Today the builders have come out, removed a tile and there is black mould behind it and the rest are completely loose, only held in place by the grout it would seem.

What could cause this? They say they will 'fix' it, but they have 'fixed' many other things badly in the house so I'd like to be sure it's not just a bodge.

Thanks, Ted

 

[opps]

I suspect that they may have simply tiled over the plaster without first sealing it.

At an absolute minimum, I would apply SBR first, tanking would be the better option.

It looks like the water in the adhesive sucked in to the plaster, leaving you with tiles that are easy to remove.

Additionally, I can see no evidence of the shower tray having been siliconed to the wall.

 

[opps]

You should not apply cement based adhesive over gypsum plaster without sealing it first.

Not only do you risk the suction pulling the water out before it cures, there is also a risk of ettringite crystals forming.

Looking at how little adhesive has stuck to the plaster... I would want the whole lot removed.

I tile, but it isn't my day job, so perhaps wait for a pro to respond before escalating things.

 

[opps]

They seem to have used moisture resistant plasterboard- which is good...

Just a shame that they decided to not seal the plaster.

My bread and butter is decorating. Over the years, I have seen loads of "professional" tilers, tile straight over bare plaster. I guess they are unwilling to prime the plaster and come back the following day to tile.

 

[TeaAndBiscuits]

Apart from the lack of tanking/sealing (or preferably using a proper tile backer instead of plaster board) there was crap adhesive coverage. Should be as close as possible to 100% in a wet area. Looks like this was ~50% coverage.

Pretty crappy job all round. Needs completely ripping out and starting again - having a load of tiles fall off the wall on you in the shower is going to be a bad day.

 

[TedStriker71]

Thanks for all the replies.

We have agreed with the builder that all of the tiles will be removed, the wall will be sealed (there has been talk of PVA) and new tiles fitted. Can you explain 'tanking' please? Not something I'm familiar with.

I'll update this thread with the outcome as I have little confidence in anything they do at this stage.

We also have a bathroom on the floor above with a shower above it and tiled area surrounding the bath up to ceiling height. Any way of checking if we have the same problem there without taking the tiles off?

Cheers, Ted

 

[Higgy28]

Thanks for all the replies.

We have agreed with the builder that all of the tiles will be removed, the wall will be sealed (there has been talk of PVA) and new tiles fitted. Can you explain 'tanking' please? Not something I'm familiar with.

I'll update this thread with the outcome as I have little confidence in anything they do at this stage.

We also have a bathroom on the floor above with a shower above it and tiled area surrounding the bath up to ceiling height. Any way of checking if we have the same problem there without taking the tiles off?

Cheers, Ted

Don't let them use PVA. Honestly I think you should tell them to get someone else in who knows what they are doing...

 

[TedStriker71]

Don't let them use PVA. Honestly I think you should tell them to get someone else in who knows what they are doing...

To be fair it was the plumber that said PVA and he's not the tiler, nor was the tiler there at the time. I'll speak to the tiler and ask what they plan to use.

Is 'tanking' necessary? And if so, what is it

Thanks!

 

[mrrusty]

tanking for showers https://dunloptrade.com/products/shower-waterproofing-kit

 

[racey1979]

Tanking is a waterproof barrier between your tiles and substrate (your walls/floor which can be plaster board, brick, concrete, breeze block etc etc). There are different kits available, some are liquid that you apply like a paint and some are a stick on membrane that comes on a roll. I'm by no means an expert, and if anyone thinks any of this info is incorrect then please challenge, but wet areas like a shower area should be tanked because tile grout is not water PROOF, it is only water RESISTANT and by the looks you just have normal skimmed plaster board which will fail if it gets wet. And looking at the photos, it IS getting wet, evidently. A good installer would have used something like cement board such as Hardie Backer or Aqua panel...or some water proof tile backer board (there are lots). I would IDEALLY want the plaster boards ripping off the walls and starting from scratch, or a tanking kit applied to the existing walls before re-tiling, neither is a really big job to someone who knows what they are doing, it's not even that difficult DIY. If I was you personally, I would spend a good few hours on Youtube as there are loads of good videos regarding shower installs, tanking, substrate materials and how to do things properly etc. A little knowledge goes a long way when it comes to challenging someone, and in your case that is clearly a complete bodge job, it's rubbish. Having this info is invaluable when it comes to standing stand your ground and demanding that the job is done correctly, and from what I can gather tanking is now a mandatory building code when it comes to wet areas like a shower, so look into this and get some more advice.

Tanking A Tiled Bathroom Is Now Mandatory…

Bathrooms & Wetroom Must Be Tanked To Comply With British Standards Institute (BSI) for BS 5385-1. Do you need to tank a bathroom? British Building Standards.

www.rubberduckbathrooms.co.uk

 

[TedStriker71]

Thanks for the reply. I'll reply in more detail soon, but just to remind you - this is a new build house. If they have built it like this I would imagine NHBC would be interested, as would all the owners of the other houses in the development, which have likely been built the same way. I have had no end of problems with this developer and would love the opportunity to rain done some proper consequences on them.

 

[Diver Fred]

A previous long term girlfriend nearly lost her legs to a badly built shower wall.. The shower tiling had been applied to plasterboard on studding, then grouted. Getting out of the shower one evening she knocked the wall and it collapsed completely in shards not complete tiles; luckily her reactions were extremely good and she leapt out of the shower when she saw the first tile move.
That one occurrence put me off tiles in a shower for life! I much prefer Shower panelling.

I'm no plumber or plasterer but in the last ten years I've either seen or helped with bathroom improvements.

The first room I saw 'Tanked' was in a refurbishment (for a builder) - the bathroom guy used a tanking material applied in the same manner as plaster - he did say it could be applied by brush (or trowel), in his opinion you didn't get a good enough coating by brush.

Subsequent bathroom refurb's I've seen, the chap I help uses 'Hardie Backer' boards screwed to the wall (at 150 or 200mm intervals) once the shower tray is in place. He applies adhesive 100% to both tile (Thinly) and wall. Meticulously silicons around the shower tray to wall seam.

 

[oldbutnotdead]

Wonder why the builders skimmed the moisture-resistant boards- waste of time and money skimming then tiling.
Looking at those pics all the tiling will need pulling off and redoing, you are right to be concerned about the tiling elsewhere in the house.
Trying to bring pain into the developer's life will be harder (and much more expensive) than you think.

 

[mrrusty]

I see in this case that green (moisture resistant) plasterboard has been used, which IMHO is fine. If I was doing this I would pull the tiles and use the paint-on tanking kit I linked to - used it a couple of times now and it's excellent - taped seams and then a sort of rubberised gloop that dries almost hard. I've found when tiling large format it is essential to both apply adhesive to the wall and to back-butter the tiles. I have no qualms about tiles in a shower if I've done them myself!!

I silicon the tray to the wall and personally prefer to use a trim e.g. https://www.wickes.co.uk/Homelux-Bath-Seal-Pro-White-1-83m/p/229569 down on to the tray (I have had excellent results with the homelux product, but an imitation was not so good as the soft edge curled after installation) - I hate exposed silicon sealant because eventually it always seems to go black. I've had excellent success with these trims but you do have to take care to get plenty of sealant hidden under/behind them with attention on corners and ends - if you leave a gap in a corner, water can run through/behind the trim. However, installed with care they keep looking good for a very, very long time.

 

[foxhole]

Grout is not waterproof, neither is moisture resistant plasterboard , it will fail again eventually .