UFH over existing quarry tiles

[Slippery]

Hi Guys,

A customer is enquiring about UFH mat under porcelain tiles but there is already well fixed quarry tiles down. He is keen to keep the floor as low as possible but I think removing the quarry tiles would be a nightmare.
Do I need to lay an insulation mat below or could I go straight over with the mat, then self level and tile?
Half the floor is a fairly new extension so will be well insulated, there is no way of knowing what the other half is like.


Cheers in advance...

 

[J Sid]

I would have them up and insulation board.
If you decide to go over the quarry tiles I'd would definitely put two mats down and two stats for the two areas.

 

[Slippery]

Thanks Julian, I'm also concerned they may be the original damp course!

 

[Uheat - Jake]

As Julian has said, your best method would be to remove the tiles and then use an insulation board. If you can't then use two seperate controllers with two floor sensors installed, as the heat up times will be very different.