J
JimboD
I'm retiling a bathroom floor as a result of a small extension that has enlarged the room from 2m x 2m to 4m x 2m. The previous floor was chipboard and tiled using Unibond flex. adhesive by my good self. It was down for 7 years with no cracks. In fact it was bonded so well and was such a pain to remove that I ended up using a circular saw and cutting through the tile, adhesive and chipboard in one go (being careful not to go any deeper) and ripping the floor up in chunks.
The builder has subsequently installed chipboard throughout, which I now know is a less than ideal tiling surface (my fault as I wasn’t aware it was a big no go – especially after the fun I had getting the old tiles off!)
On the upside there is very little if any bounce in the floor due to the narrow span (2m) but there is the join between the old and new part of house to worry about – floor is flat but might move over time.
The room was previously always cold so wouldn’t have had a huge temperate related expansion cycle to cope with but now I plan to install heat mats which will change this factor a lot.
So, my question is what is my best option – with the goal of keeping the overall depth to a minimum as I dont want a big step up to the hall? (i.e. the common answer of “just screw some 18mm ply on top” isn’t a good one for me)
So far it appears my best bet is to fix the heat map to the chipboard and submerse it in a self leveling compound, followed by attaching a Ditra mat layer with a suitable adhesive and then tiling onto that again using a suitable adhesive.
Other paranoid option would be rip out all the floor and replace with 22mm marine ply, then as above. Possibly adding insulation board to reflect heat upwards before heat mat goes down.
Other option would be to fix 6mm backiboard to chipboard and then sit heat mat on that.
Other quick/cheap option would be to stick heat mat to floor, and then tile directly on top of that using thickish layer of suitable flexi adhesive. And cross fingers.
The new porcelain tiles are long and thin (like planks) and so might be more susceptible to cracking compared to the prev. 600x600 ones.
Any guidance appreciated
Cheers
Jim
The builder has subsequently installed chipboard throughout, which I now know is a less than ideal tiling surface (my fault as I wasn’t aware it was a big no go – especially after the fun I had getting the old tiles off!)
On the upside there is very little if any bounce in the floor due to the narrow span (2m) but there is the join between the old and new part of house to worry about – floor is flat but might move over time.
The room was previously always cold so wouldn’t have had a huge temperate related expansion cycle to cope with but now I plan to install heat mats which will change this factor a lot.
So, my question is what is my best option – with the goal of keeping the overall depth to a minimum as I dont want a big step up to the hall? (i.e. the common answer of “just screw some 18mm ply on top” isn’t a good one for me)
So far it appears my best bet is to fix the heat map to the chipboard and submerse it in a self leveling compound, followed by attaching a Ditra mat layer with a suitable adhesive and then tiling onto that again using a suitable adhesive.
Other paranoid option would be rip out all the floor and replace with 22mm marine ply, then as above. Possibly adding insulation board to reflect heat upwards before heat mat goes down.
Other option would be to fix 6mm backiboard to chipboard and then sit heat mat on that.
Other quick/cheap option would be to stick heat mat to floor, and then tile directly on top of that using thickish layer of suitable flexi adhesive. And cross fingers.
The new porcelain tiles are long and thin (like planks) and so might be more susceptible to cracking compared to the prev. 600x600 ones.
Any guidance appreciated
Cheers
Jim
Last edited by a moderator:
