Two inches of soft grout

[ceecjc1]

Hi experts,

I have an odd problem with my shower tiling. I had my bathrooms tiled four months ago. A couple of inches of grout started to discolour so I removed it but to my surprise it came out easily, like putty.

The grout immediately above and below is rock solid, it's literally only two inches of soft grout. There is no obvious leak but I know it's very difficult to figure that out.

I replaced the grout with premixed stuff (assuming the original grout might not have been mixed properly) and reapplied. Two days to set and it's still soft.

What could be preventing the grout from setting and why is it just two inches? I stuck some blue tissue in the hole after removing the grout and after an hour it was still clean and dry so if there's a damp problem it's not bad.

Some details:
- this wall is the only one which is tile on tile, and the wall itself is concrete
- the two inches are where the glass mosaic abuts regular ceramic tiles
- due to a difference in thickness, the mosaics are fixed to plywood using tile adhesive and the whole lot attached to the old tiles beneath
- the original installer is not coming to help, he just comes out with excuses then doesn't show up.

Any ideas?

Thanks folks!

 

[Richard C]

- this wall is the only one which is tile on tile

Oh dear, that can be a problem if it’s not done properly using the right materials; did the adhesive they used come out of a tub?

- the two inches are where the glass mosaic abuts regular ceramic tiles

That in itself is not a problem but it sounds the adhesive is not drying/setting under the tiles; usually what happens if a water based tub mix has been used rather than a chemical cure cement based powder adhesive.

- due to a difference in thickness, the mosaics are fixed to plywood using tile adhesive and the whole lot attached to the old tiles beneath

OH, OH dear, tile on tile is a bad enough bodge which can cause problem sif the right materials are not used but to stick a lump of ply on them & then tile over that is just a joke & in a wet area is never going to last.

the original installer is not coming to help, he just comes out with excuses then doesn't show up.

Well I’m not surprised at that cos they definitely ain’t no tiler I can tell you. It’s been bodged; unfortunately & in all probability it won’t last & that 2 inches of soft grout is only going to be the start of your problems

 

[ceecjc1]

Oh dear, that can be a problem if it’s not done properly using the right materials; did the adhesive they used come out of a tub?

There are only two narrow walls which are tile-on-tile, the rest is tile-on-plasterboard, but unfortunately the tile-on-tile walls are inside the shower. Knowing this guy, I would not expect that it has been done properly. He told me it needed special adhesive but I'm 99% certain he used the same stuff out of the same tubs he used for the rest of the bathrooms. Problem is I'm not the expert, that's why I got a guy in to do it, so if he says he did it properly how am I supposed to know?!

OH, OH dear, tile on tile is a bad enough bodge which can cause problem sif the right materials are not used but to stick a lump of ply on them & then tile over that is just a joke & in a wet area is never going to last.

I thought this was an odd thing to do but like I said above, he's supposed to be the expert, not me. The tiles are attached to the plywood with regular adhesive out of a tub, then the plywood to the old tiles using gripfill or no more nails or something, if I remember correctly. I wasn't around when that was done unfortunately.

Well I’m not surprised at that cos they definitely ain’t no tiler I can tell you. It’s been bodged; unfortunately & in all probability it won’t last & that 2 inches of soft grout is only going to be the start of your problems

If the tiles need to come down then at least it's only a small section of wall but I'd rather that not be the case.

This guy was from ratedpeople - great website in theory but unreliable crap in reality. You may as well get your granny to do the tiling. To his credit he rang me back when I called to tell him about the problem and even arranged to visit, but that's the last I heard from him. Would not recommend. Nice guy, but absolutely useless.

 

[Richard C]

There are only two narrow walls which are tile-on-tile,

It can be done using the correct prep & tiling materials but it’s really just a bodge & I’ve only ever done it if there has been no alternative; always take the old tiles down. Did he give good reason for not removing the old tiles other than saving the time it takes!

the rest is tile-on-plasterboard, but unfortunately the tile-on-tile walls are inside the shower. Knowing this guy, I would not expect that it has been done properly.

Is there any plaster board inside the shower area? Plasterboard in a bathroom should be Moisture Resistant (usually green) but in a wet area it must be tanked if you want it to last; much better to use a waterproof tile backer board in wet areas.

He told me it needed special adhesive but I'm 99% certain he used the same stuff out of the same tubs he used for the rest of the bathrooms.

What type & size of tiles do you have? Tub mix is evaporative cure & can only be used on wall tiles les than 8mm thick & under around 250mm square, otherwise it takes an age to set & in extreme cases won’t set under large tiles at all; it should never be used for floor tiles.

Problem is I'm not the expert, that's why I got a guy in to do it, so if he says he did it properly how am I supposed to know? I thought this was an odd thing to do but like I said above, he's supposed to be the expert, not me.

As with all trades, that’s the difficult bit; you should try to use someone with a reputation you know & trust & to protect your own interest it’s always a good idea to try & understand a little about the materials & processes involved to help make your decision. Even high prices won’t guarantee they actually know what they are doing or understand & use quality trade materials of the correct type; unbelievably & from what I've seen on ocasion, some can’t even tile properly!

The tiles are attached to the plywood with regular adhesive out of a tub, then the plywood to the old tiles using gripfill or no more nails or something, if I remember correctly.

I would never stick packers to the wall to fill out for thinner border tiles, what I do is use a cement based powder adhesive which, being chemical cure, doesn’t rely on evaporation to set; it will also tolerate much greater thickness that tub adhesive. It’s also a much better adhesive than tub mix & worthwhile using in wet areas even if the tile size/weight doesn’t warrant it. A lump of plasterboard would have at least been better than ply; ply is totally unsuitable in a wet area & if it’s just ordinary ply rather than WBP, it will most likely de-laminate.

If the tiles need to come down then at least it's only a small section of wall but I'd rather that not be the case.

It sounds as if the adhesive behind the tiles is still trying to dry out, if you rake out the grout lines in the affected area & leave it to dry out thoroughly (which could take weeks) then re-grout with a quality product it may at least make the shower useable again. But you may still get problems & if there is PB inside the shower & it hasn’t been tanked, it’s unlikely to last any length of time particularly if he’s used the wrong type of adhesive for your tiles. Do you know what brand & type of tub adhesive was used?

This guy was from ratedpeople - great website in theory but unreliable crap in reality. You may as well get your granny to do the tiling. To his credit he rang me back when I called to tell him about the problem and even arranged to visit, but that's the last I heard from him. Would not recommend. Nice guy, but absolutely useless.

They are in it to make money either direct from registration fees, selling individual leads about work in your specific area, web based advertising & possibly all three. I don’t belong to any & don’t know what if any checks they make before accepting trades & of course their annual fee; they are also self-regulatory which never really seems to work & even the mandatory registration authorities (gas, eclectics etc) have their rouges & get it wrong on occasions. You could try complaining to them when it all goes wrong but you will need to provide some form of inspection report.

Commiserations; from what you’ve said, I fear your granny may have made a better job of it!

 

[ceecjc1]

Thanks Richard for the useful advice. Sounds like you know what you're talking about - I wish you had done my tiles!

It can be done using the correct prep & tiling materials but it’s really just a bodge & I’ve only ever done it if there has been no alternative; always take the old tiles down. Did he give good reason for not removing the old tiles other than saving the time it takes!

The strange thing is that out of two bathrooms and 50m2 of tiles overall, he went to the effort of removing all of the old tiles and replacing the green/blue plasterboard where necessary, so it looked like he was doing a proper job. The only section he left the old tiles up were in two narrow walls on the en suite, probably about 4m2 in all. The old tiles are from 2004 so not that old. His reason was that they didn't need to come down so they stayed up.

Is there any plaster board inside the shower area? Plasterboard in a bathroom should be Moisture Resistant (usually green) but in a wet area it must be tanked if you want it to last; much better to use a waterproof tile backer board in wet areas.

It's blue/green plasterboard everywhere, can't remember what he called it.

What type & size of tiles do you have? Tub mix is evaporative cure & can only be used on wall tiles les than 8mm thick & under around 250mm square, otherwise it takes an age to set & in extreme cases won’t set under large tiles at all; it should never be used for floor tiles.

He seems to have done a very good job on the floor - very even. These were porcelain tiles and had a different type of adhesive - RapidSet I think it was. He applied adhesive to the floor then stuck the tiles down. He took a different approach with the wall tiles, which are 300x600mm ceramic. I'd say he was quite sparing with the adhesive on the wall tiles, applying some to the back of the tile rather than covering the wall.

As with all trades, that’s the difficult bit; you should try to use someone with a reputation you know & trust & to protect your own interest it’s always a good idea to try & understand a little about the materials & processes involved to help make your decision. Even high prices won’t guarantee they actually know what they are doing or understand & use quality trade materials of the correct type; unbelievably & from what I've seen on ocasion, some can’t even tile properly!

You're spot on there. I spoke to a lot of tilers and tried to get as much information as possible but as with any other trade, ask ten different guys and you'll get ten different answers (even gas-safe guys disagree with each other). I'm reasonably new to the area and don't know many people who could recommend a tiler. The only recommendation I got was for a guy who when he came round to quote clearly knew what he was doing but came in at 3-4x the price of the other guys. If I hadn't just bought a house I might have had more cash to take him on but I had to go the cheaper route. The guy I actually went with wasn't the cheapest but he did seem to know what he was doing, didn't pressure sell and had good ratings on ratedpeople. I thought I had made a good decision

I would never stick packers to the wall to fill out for thinner border tiles, what I do is use a cement based powder adhesive which, being chemical cure, doesn’t rely on evaporation to set; it will also tolerate much greater thickness that tub adhesive. It’s also a much better adhesive than tub mix & worthwhile using in wet areas even if the tile size/weight doesn’t warrant it. A lump of plasterboard would have at least been better than ply; ply is totally unsuitable in a wet area & if it’s just ordinary ply rather than WBP, it will most likely de-laminate.

He said it was some kind of marine ply, but it wasn't blue/green so I had to take his word for it.

Commiserations; from what you’ve said, I fear your granny may have made a better job of it!

I'll give her a call and see if she's available to do the repair. She's installing a new kitchen and may have time next week

 

[Richard C]

It's blue/green plasterboard everywhere, can't remember what he called it.

Well at least he replaced the plasterboard but, as I said, it should be tanked in wet areas if you want it to last. Apart from expensive epoxy products, waterproof adhesive & grout is only waterproof” in the sense it won’t (shouldn’t) disintegrate when wet, it’s not impervious to water so it’s important the tile base is truly waterproof if regular wetting of the tiles is going to occur.

I'd say he was quite sparing with the adhesive on the wall tiles, applying some to the back of the tile rather than covering the wall.

Sounds like he’s dot & dabbed the tiles onto the wall, if so that’s a complete bodge & is useless in a wet area where you need 100% adhesive bed coverage.

He said it was some kind of marine ply, but it wasn't blue/green so I had to take his word for it.

As above regarding waterproof adhesive/grout. Marine ply uses waterproof adhesive to bond the plies but it’s still wood & wood expands when exposed to moisture & if it gets to it & the ply expands, your tiles will fall off.

 

[ceecjc1]

It sounds like a disaster waiting to happen...maybe I should just move house.

Is there anything I can apply to the grout to seal it and make it more waterproof in the meantime?

 

[Richard C]

You can try a grout sealer;

http://www.tilersmerchants.co.uk/Li...r-500ml.html?gclid=CO6lqZjghq8CFUEOfAodkF8wAg

http://www.tiledoctor.co.uk/GroutSealer.html

 

[ceecjc1]

Looks good, thanks for that! Guess these won't seal water so much, so I still have the original problem