I am installing a new bathroom floor. I plan on getting an electric underfloor heating mat, 2 backer boards for under the heating, screed the mat and tile over this.
My question is can I place the back boards on the cork vinyl(even though it's got glue on top) or do I need to remove the cork.
Another option is cleaning the glue off the cork and using the cork as the subfloor. Is this possible?
Thanks for the help, first timer here.
When I am redoing a bathroom and adding the needed backer board to a subfloor assembly, I would remove all existing finish floors no matter how many to get back down to the original subfloor. Then evaluate that, repair it if needed, add to it if needed to make it stiff enough for tile, then add the one layer of 1/4" backer board, then the heating wires, screed, then thinset and tile.
All these layers together will add up to a reasonably thick floor, if the all original flooring is not removed, you will have a potentially sizable rise in height from one floor to another
I've never had to do this (install tile over cork), but I think you need to remove the cork.
Backer/cement boards needs to be firmly fastened to the sub-floor. Any kind of softness, give, or "springiness" will be transferred up the tiles and will cause the tiles or the tile joints to crack.
If you read James Hardie installation you need to thinset the board down with modified thinset so over cork no don't do it
You can check with the heating mat manufacture to determine if the cork is a suitable subfloor. But I don't think that cork is a good underlay for tile. It's too soft.
The target finished height of the floor is a key consideration. If you install materials over the top of the existing floor, the new floor level will be higher. That can be awkward, especially in a bathroom. To stay at the current floor height, you need to remove something before adding something.
Do not ever tile over cork.
Unless you poor a 5ft thick layer of concrete over it 1st. Then it might work.
