Can I put Prowarm insulation boards down over old tile adhesive?

[Jonbud]

Hi All,

I’ve just finished removing my old kitchen floor tiles. My intention is to install electric underfloor heating and then re tile.

The whole floor is now covered with old tile adhesive. At least that’s what I think it is. It looks and feels like concrete. This is on top of a concrete floor. My question is can I just put my Prowarm backer boards straight down onto this old adhesive or does it all have to come up?

If it has to come up it’ll be a huge job as the entire floor is covered with it.

I’ve attached some pictures.

Any help or advice would be greatly appreciated.

Jon.

 

[Stanley services]

The old adhesive is too jagged to be next to the cables of underfloor heating as it will damage the heating mesh. the correct way of tackling this is to take the adhesive up. You can do this, which is hard work. Or you could pour a sufficient amount of self levelling floor compound on top until the floor is smooth. Takes 24 hours to properly cure.