Tiling on Tiles

sjd224 · Posted: Mon Apr 03, 2006 6:44 pm Post Subject:

Everywhere I look on these forums, I see advice that attempts to reassure me that I may tile on existing firmly attached tiles. So far, I'm convinced, but before I begin and watch £200 worth of ceramics sliding slowly down the wall, one last check;
I will be tiling on shiny glazed wall tiles. Are there any special requirements? Should I score the glaze? If so, should I score deeply, or just use heavy grade sandpaper or wire wool?

joe-90 · Posted: Mon Apr 03, 2006 7:40 pm Post Subject:

Tiling on tiles is a bit of a bodge really, but if you must, just make sure they are very clean and dry before you start. They don't need scoring. Make sure you set up battens so that they don't slip and stay level.

joe

gcol · Posted: Mon Apr 03, 2006 7:44 pm Post Subject:

Just give the tiles a wash down with sugar soap, rinse off and dry.
*Do not apply pva to existing tiles - there's no need..... fine on plaster/plasterboard but not onto existing tiles.*
Then tile as normal. You'll need to leave about 3 days for the adhesive to go off before you grout though - this is cause there's nowhere for the moisture in it to go so you need to let it go off properly.

Moz · Posted: Fri Apr 07, 2006 5:23 pm Post Subject:

I personally would take them off .... but if must , I would give them a scoring with wet an dry rough sand paper as your sugar soaping an only pva if the powder mix adhesive says so ... BAL is the best Ive always used ...

Tim B · Posted: Sat Apr 08, 2006 11:32 am Post Subject:

Here a few points that may be worth considering.

Tile Over Tile

A very common decision to make when re-tiling is whether to tile over existing tile or remove the old tiles first.

It is quite common to tile over existing tile, and should not be a problem, but there are a few points to bear in mind, or worth considering.

If tiling over tile
The existing tiles must be soundly bonded to the walls. Obviously, no matter how well fixed the new tiles are, if the old tiles de-bond from the wall and fall off, then so will the new ones. Make sure the old tiles are well fixed.

One way to check is to gently tap them. If it sounds very hollow then they are likely not well bonded. Pay particular attention to wet areas which are more likely to have problems.

The existing tiles need to be clean and free of grease or other contaminants which could affect the bond of the adhesive used for the new tiles.

Some backgrounds such as plaster and plasterboard have a recommended weight limit for a square unit of measurement. That means that for instance plasterboard will have a maximum weight of tiles or stone you can fix to it, which if surpassed may cause a structural failure.

This is unlikely to be a problem if both old and new tiles are smaller format, thinner tiles, but could be an issue if using large format, heavier tiles on top. It especially likely to be a problem with natural stone tiles which tend to be heavier due to their thickness.

Only certain tile adhesives are suitable for tile on tile. Check manufacturers instructions or with your tiler.

One last thing to consider is the aesthetics. Tile over tile can be noticeable around the perimeters of a room such as coving, door jambs, and especially if the room is only half tiled.

Why bother tiling over tile ?
The reason this might be a good option is mostly time and money. It can be time consuming to remove old tiles and also the wall surface may be damaged by removing the tiles and need subsequent making good before re-tiling. This is obviously going to cost more if you are employing someone.

Another reason is that if you have say a good quality bath suite, then there is obviously a risk of damaging it whilst removing the old tiles. Of course, this should be avoidable but nevertheless, it is a potential problem.

howiel · Posted: Tue Apr 11, 2006 9:04 am Post Subject:

Unibond make Tile on tile adhesive I saw it in B&Q about £20 for a large tub

Softus · Posted: Tue Apr 11, 2006 8:53 pm Post Subject:

Please please please please please, please, PLEASE, don't buy tile adhesive at BNF&Q.

howiel · Posted: Wed Apr 12, 2006 2:43 pm Post Subject:

Softus wrote:

Please please please please please, please, PLEASE, don't buy tile adhesive at BNF&Q.

Eh ?!!? enlighten me

Moz · Posted: Wed Apr 12, 2006 4:35 pm Post Subject:

Tub mix is awful stuff an when they start to fail remember reading it here ...

sjd224 · Posted: Mon May 08, 2006 6:30 pm Post Subject:

You may find my original question about tiling on tiles near the very top of this topic. Let me now update those of you good enough to reply. I started to "tile on tile" as well as "tile on wood". All surfaces were ptrepared correctly, as according to the above advice and other fora. Guess what? I spent three days tiling a tiny room, mainly due to having to re-tile areas where the tiles just fell off again, and eventually, after some choice language, ripped the whole damn lot off, along with the old tiles and the old wood, scraped it all down to bare plaster, made good where necessary, started again, and now have what I was after all the time - a well tiles en-suite.
Advice to all those thinking of short cutting and leaving old tiles on.
DON'T!!!!!!!!!

gcol · Posted: Mon May 08, 2006 6:36 pm Post Subject:

Ooooo angry chap. Tiling onto existing tiles does work. You've obviously done something wrong. What adhesive did you use? What preparation did you do?

__________________
If I'm curt with you it's because time is a factor. The Wolf.

SteveStrat335 · Posted: Tue May 09, 2006 12:08 am Post Subject:

The best way to check is to spread some adhesive on the surface of the old tiles. If it's a b*****r to remove then the job's a good 'un.

On the other hand, if it comes away easily then more surface preparation is necessary. Probably soap, or silicon cleaning polish is interfering with the adhesion.

sjd224 · Posted: Wed May 10, 2006 1:47 pm Post Subject:

Tiles were thoroughly sugar soaped and scrubbed, wood was sanded with coarse sandpaper and scored (after sugar soaping). The point about putting some adhesive on the surface of the tiles and trying to scrape it off later is a good one. My adhesive was left on the surface of the tiles, (not the backs of those I took off) and just scraped away, turning to dust.

warehouseman · Posted: Wed May 10, 2006 8:45 pm Post Subject:

If I may add one further point; As you know, most tilers would rip the entire lot off & start afresh. However, if wanting to tile on tile, I would always recommend using a non-slip FLEXIBLE adhesive which has better adhesion on that surface & is more waterproof, plus it will go onto any wood panelling if necessary.

uppatree · Posted: Thu Apr 17, 2008 8:50 pm Post Subject: Tiling on tiles

If tiling on tiles was a tried and tested recommended method of installation then this debate would never have arisen. DON'T DO IT!
As with any job undertaken weather it be diy or professional, preparation is the key. Always start with a sound substrate and you will be giving yourself peace of mind for years to come. Who in their right mind would want to stare at a wall wondering when its going to fall off?