Hi all

I have tiled two walls in a bathroom for a friend using unibond all purpose adhesive, premix. One wall is painted and the other is on fresh plaster.

After 48hrs the tile adhesive is not setting under the tiles correctly under the tiles. It is left semi moist and crumbly and the the tiles can be easily prised away from the wall cleanly leaving the adhesive stuck to the wall.

I think it may be because the homeowner is using the shower in the bathroom at the same time as the tiling is taking place. I was thikning that maybe the steam or moisture may be getting under the tiles and keeping the adhesive moist.

Any ideas or similar experiences?

Matt

The adhesive needs air to get to it to set and it can take a long time. They certainly can't use the shower in the same area. The pros on here will tell you how bad the adhesive is

hi matt,,1st what size of tiles are you fixing?

tubbed adhesive sets with air contact and isnt suitable for larger tiles,also unibond isnt a high quality adhesive to be using in the 1st place,

the main issue i can see is that your friend is using a shower while your tiling so no grout is in and it hasnt set? sorry but common sense needs to be switched on here by your friend,i would take the whole lot down,clean the undet adhesive off and start again to be honest as you have said moisture and plenty water will have gone behind the tiles hope this helps

As you state "one wall is painted", unfortunatly paint is not a good substrate for tiling. I would recomend taking off the tiles, strip the paint. Then prime walls with SBR, use a cement based adhesive ( Mapei) or the like. Sorry to give bad news, but tubbed adhesive has very limited uses imo

Just to give you an idea of tubbed adhesive. Even when it is dry and hard you can soak it for an hour or two and it's completely soft again therefore if the area is wet or steamy the adhesive will never set.

To add to the above how thick did you apply the adhesive?

Originally Posted by united

To add to the above how thick did you apply the adhesive?

My thoughts too. If the adhesive is crumbling then it is to thick

Originally Posted by Phil Hobson

As you state "one wall is painted", unfortunatly paint is not a good substrate for tiling. I would recomend taking off the tiles, strip the paint. Then prime walls with SBR, use a cement based adhesive ( Mapei) or the like. Sorry to give bad news, but tubbed adhesive has very limited uses imo

All really good advice, and the only course of action to complete the job to a quality finish is as Phil said, it's back to the start I'm afraid and the quicker you get the tiles off the easier it will be.

Maybe not what you want to hear but it's best to put it right now rather than have to redo the whole lot in a month if you don't.

The material you're fixing is also important, ceramic or porcelain makes a big difference as to how the adhesives behave. Use a quality adhesive such as BAL or Mapei and a proprietary bonding agent and you should have no problems at all.

If in doubt take a tile into your local specialist tiling store (not a DIY shed) and ask their advice.

Good luck with it.

Hi All

Thanks for the great info.

The tiles are 200 x 250 ceramic tiles. The depth of the adhesive is about 3-4mm so I don't think I've done it too thick.

I've used a different adhesive for the rest of the bathrooom. I used a unibond non-readymix all purpose adhesive which has set really well and I used this around the bath and shower without issues. I'm guessing this is because I managed to get the grouting in before the shower started being used.

I only used the ready mix as I am just finishing up the edging and a few tiles around a coving, and I didn't want to buy another large bag of adhesive for only 20 or so tiles.

So I guess I'll tell them to stop using the shower and I'll start pulling those tiles off. I'll also go back to the non-ready mix adhesive.

Thanks again for all your advice.

Matt

good luck matt..