tiles falling off in shower

[Roger465]

I’ve had to remove and replace tiles from the lower 3 or 4 feet of each of its 3 walls, due to damp damage from a cracked shower tray that went unnoticed by the previous owners for years, as far as I know. I’ve replaced the tray, and everything is bone dry, as the shower hasn’t been used since they discovered the crack years ago.

The left wall is structural, with some of the original tile adhesive remaining, so I’ve just stuck the tiles on again with some of the adhesive in the pic below, and they’re adhering very firmly, as you'd expect. The bottom 3 feet or so of the other two (stud) walls have had to be replaced with Moistsure Backer Board, and the tiles fixed to that with the same adhesive, about 3 days ago.

Today I find that none of the tiles on the backer board walls have stuck properly – they’re dropping off, so I just pulled them all off again. As you can see from the epics below, the tiles are covered with adhesive, stuck firmly – but virtually no adhesive has adhered to the backer board.

So the problem seems to be with the backer board. I somehow managed to miss the bit in the instructions which said I should seal it first with acrylic primer, so I’m going to do that – but do you think that’s definitely the problem, or have I done something else monumentally stupid?

I asked the guys at the builders’ yard, and they said they sold an awful lot of backer board, but the builders who bought it didn’t also buy primer.

Very very near the end of my tether with this project guys – any advice much appreciated

 

[MeldrewsMate]

You've clearly identified that the tile adhesive works well on the old sections of wall, and not on the new backer board; could it be that the moisture in the adhesive has been absorbed quickly into the board - thus the need to seal it. You may discover that the builders who didn't buy the expensive primer used a diluted PVA solution in lieu of it.

My opinion is that you will have much better results after applying the primer. Try not to allow the adhesive to dry out in hot weather*, as again this would lead to the adhesive not adhering as well as it could.

MM

*clearly problems due to hot weather do not apply to Scotland.

 

[Roger465]

You've clearly identified that the tile adhesive works well on the old sections of wall, and not on the new backer board; could it be that the moisture in the adhesive has been absorbed quickly into the board - thus the need to seal it.

I don’t see any other conclusion to draw, really – glad you agree

You may discover that the builders who didn't buy the expensive primer used a diluted PVA solution in lieu of it.

Yes, of course. That’ll be it. In fact, now I remember somebody saying to me “paint it all with diluted wood glue before tiling”, and I thought he just needed to up his drugs…

*clearly problems due to hot weather do not apply to Scotland.

Normally nor here in N Ireland either, but it’s a bloody heat wave. However, as luck would have it, the en-suite is in the middle of the house, no windows, and is pleasantly cool!


I’ll report back when I’ve tried it again… have to scrape the adhesive off the back of about 30 sodding tiles first though

 

[Keithmac]

Buy some proper self mix adhesive (powdered form), the premix stuff in tubs is pretty poor in comparison..

 

[Roger465]

Buy some proper self mix adhesive (powdered form), the premix stuff in tubs is pretty poor in comparison..

Mate, I hear what you say, but I think if we added the "me" factor in for mixing it properly etc in my current stressed/exhausted/totally ****ed off state (I've got guys in with a digger destroying my garden etc at the same time, and car problems )... also, because the tray is about an inch lower profile than the old one, the bottom row of tiles definitely won't line up - so I'm tiling form the top down, a row at a time, holding them in place till they dry, then the next row down and so on. I think if I had to mix a batch of adhesive every time I did a row, I'd go mental and commit an action of mass destruction!

I'll let you know how I get on...

 

[jammmy]

woops.

 

[Roger465]

woops.

Did you post something just now, about why not to use PVA, and delete it? It was quite interesting.

But I’m using acrylic primer, which is what the backer board manufacturer recommends, so HOPEFULLY it’ll be OK…

 

[Keithmac]

Mate, I hear what you say, but I think if we added the "me" factor in for mixing it properly etc in my current stressed/exhausted/totally ****ed off state (I've got guys in with a digger destroying my garden etc at the same time, and car problems )... also, because the tray is about an inch lower profile than the old one, the bottom row of tiles definitely won't line up - so I'm tiling form the top down, a row at a time, holding them in place till they dry, then the next row down and so on. I think if I had to mix a batch of adhesive every time I did a row, I'd go mental and commit an action of mass destruction!

I'll let you know how I get on...

I had to start in the "wrong place", believe me the act of mixing proper adhesive is worth the effort!.

Honestly for the extra step you'll get a far better job at the end.

 

[Keithmac]

 

[Roger465]

I had to start in the "wrong place", believe me the act of mixing proper adhesive is worth the effort!.

Honestly for the extra step you'll get a far better job at the end.

Hey, lovely job! I thought I was the only one who thought of using tape to hold them up

Well, I’d already stuck a row on using the pre-mixed tub, so it was kind of too late anyway. But I gave them a quick tug this morning, and they seem to be stuck very fast after pre-priming

I was going to say thanks for the tip, I’ll mix my own stuff next time.. but believe me, there isn't going to be a next time…

 

[Keithmac]

I said that after tiling the kitchen but theres always a next time!.

The blue heavy duty masking tape is great to hold them in position overnight while the adhesive sets up.

Nice to see you've sorted your problem out and good look with the rest of the tiling.

This is what I started out with, it was a right chew!.

 

[Roger465]

HAH! With the greatest of respect, and to quote Monty Python, LUXURY.

This is what I started with...

 

[Roger465]

My only real problem now is that, unaccountably, the shower trays available nowadays appear to be subtly different in size from the one which was fitted here, when the house was built in 1994, so my bottom course of tiles is an inch or two short of reaching it (so I’ll have a gap between the bottom course and the top of the tray) – also this tray is a true 760 x 760, whereas the old one seems to have been an inch or two bigger (had to smash it to remove it, so can’t be accurate), so I have a big gap round the sides too…


My tiles are also vintage 1994, so obviously no longer available – I guess I’ll have to run a narrow course of either plain pink, or white, round the bottom to make the deficit up… heigh ho…

 

[Keithmac]

You've top trumped me there!, although we only have 1 toilet so was a bit of a faf working around family toilet stops and flushing with a bucket!.

Pressure was on when I finally removed the old toilet and the new one leaked from the cistern fittings (took 3 goes to seal it all up properly!).

You've deffinitely got your work cut out there!, all worth it in the end though..

 

[Hot&Cold]

Roger465,see the shower project is taking shape

As mentioned self mix adhesive has its advantages especially on the mesh faced backer board,have in the past just prior to tiling rub the area with a wet sponge and trowel the adhesive on the wall,forcing it into the mesh.then use a notched trowel.

That process has always got good initial tile suction even on very hot days like today.

Good luck