Bathroom floor tiling.......on old quarry tiles

21 Nov 2008
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United Kingdom
Hi all

Not been back for a while, but if you can help I am looking for some divine inspiration please.

Ok, so all the bathroom walls have been nicely tiled by my own fair hand and I am very happy with the result, but we were planning to put a vinyl floor covering down, however, being unable to find something we both like we have decided to tile the floor as well.

Now, the last time I tiled a floor I had wooden floor boards, which I fully secured and then a marine ply over the top, then a heat trace , self levelling then the floor tile finish.

Since then we have moved, and I now have a very good quarry tiled floor
( the bathroom was the kitchen ) the existing quarry tiles are about 4 inch square, are all good and fixed down well.

What I want to do is put the new bathroom tiles over the top of the existing 4 inch tiles and add underfloor heat trace at the same time.

I am aware of the fact that I may need to prime the existing tiles with a coating, but what ?

What's best, and do I need to put down any insulation to reflect the underfloor heating back up

Existing floor is very good and fairly level.

Thanks in advance for any replies
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I would never tile over tile if it could possibly be avoided. Not least, you will be raising the FFL quite a bit which often will create knock-on difficulties.
Yes you can go over it, its not ideal, but its fine. If using UFH i would advise insulation board or you''l be heating both!
The insulation board and tiles will add a lot of height, so assuming you can live with that, clean the tiles well, mix a slurry coat of acrylic bonding and floor tile adhesive (powdered), paint this over to prime and then tile as normal.
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Thanks for the replies TPT and REE.

Sorry for not replying back before, other things got in the way.

The time is nearing to sort my floor and in the time since , I have been thinking....dangerous I know.

Taking advise , I will now be removing the 4 inch quarry tiles currently on my bathroom floor, goes against the grain as they are so good and solid.

This should give me about 45mm minimum this includes the 10mm or so under the existing quarry tiles, to get me back to the existing floor screed.

This would bring me back to existing carpet level outside the bathroom and i think i could live with a further 10mm in level change in the bathroom.

So, about 55mm maximum to play with.

In this i have to level the existing screed, insulate, fit the underfloor heating and new finished tile surface.

Stop laughing !

What are my insulation options on my existing screed floor, i assume a board, but is anything else available that's not going to eat into my available height.

Fortunately i can go higher , as i have not decorated the hall outside the bathroom yet, but i don't want to really, and my only other option is to re screed the bathroom floor lower.

Can someone recommend a good underfloor heat trace as well please, mid range prices please, or slightly higher.

Thanks for any help in advance, its appreciated.

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