tiling over existing ceramic tiles

[money2have]

Hi i have done several tiling projects before on blank walls or walls where i have taken tiles off. I have a problem with a shower room at present that i need to tile with ceramic tiles. I cant take old tiles off as the whole plasterboard wall comes with them, so i want to tile over the top.
Any tips, e.g. should i scour old existing tiles first or coat them with pva, or any other hints. dont fancy them all falling off !!!!

 

[jefoss]

imho i wouldnt ever tile over tiles, always take them off and start again if the boards come off, replace them.

 

[gcol]

Tiling onto tiles is fine so long as the existing tiles are sound. Give them a good washing down with sugar soap (and rinse) before you tile.
You'll need to leave the adhesive to set for about 3 days before grouting.

It's worth mentioning that the weight of two layers of tiles can be problematic if you have thick tiles on a plastered wall. Plasterboard or Aquapanel walls will support more weight.

You should arrange it so that the grout joints in the new tiles don't match up with the joints on the original layer. Stagger them.
As mentioned though, it's always better if you can take the old tiles off.
Good luck.

 

[money2have]

thanks i will wash thouroughly and stagger joints anyway, but wondered if scratching the tiles was necessary to give better adhesion properties

 

[gcol]

No, not necessary.

 

[musky72]

Hi,

I did exactly what you wanted to do and I have some patchy marks on the new tiles that are sat on top of the existing tiles, I wonder if you had similar issues?

Looks like because the tile adhesive is not 'drawing' into the plasterboard (as there is a tile in the way), it has seeped through to the new tile and is showing as a blemish on the glaze.

I am hoping that they may dry out and are just taking a little longer than normal owing to the existing tiles in place.

Cheers

Steve

 

[Graemevw]

When tiling over tiles it can help to coat the exitsting tiles in adhesive first.

Using the smooth, no notch, edge of your trowel spread adhesive over the tiles.
Not alot.
Keep the trowel as tight to the tiles as possible.

This will leave very little adhesive on the tiles but will bring the grout joints and any edge bevel flush with the tiles face.

It will probably leave a very slight film of adhesive on the tiles face too.

Leave this to dry at least over night before you tile over.

This layer of adhesive gives the new adhesive something to bite onto when you tile over them, helps them to stop sliding down the wall as the adhesive wont have as much grab as it would when tiling over a porous surface.

Doing this allows you to tile over tile without the need for any battons or support for the first row.

 

[Richard C]

Musky 72; this thread was already 4 years old when you posted it!

 

[musky72]

Does that cause a problem?

 

[Richard C]

Does that cause a problem?

The original OP has probably long gone; time, method & materials move on & it can be tedious for daily contributors to read out dated posts. It’s always best to stick to your own thread rather than hi-jack someone else’s; I’ve also replied to your thread.

 

[musky72]

Sorry about that, I saw a post about tiling over existing tiles and thought I would ask a question.

Point noted, will start a new thread in the future.