underfloor heating in bathroom help please !!

[babyblog]

Hi
I'm a DIYer so forgive my question if it is obvious what i need to do here !!
Here goes with my issue. I am installing a new bathroom on a first floor level. I have a wooden floor. I will be putting down travetine tiles on the floor. I want to install a heating mat. So, i was planning on putting down and securing 6mm plywood over the floorboards -- then the heating mat on the ply -- then tiling directly onto the heating mat. can i do this ??
Alternatively, would i put down a thermal board, instead of ply or thermal board and ply -- then lay the heating mat -- then tile over.....i don't have much idea what i need to do....so any advice GREATLY appreciated !!!

 

[Mike]

the floor has to be solid before before laying any boards. you'd be best laying hardi cement boards or similar, put them down on spf adhesive and screwed every 300 mm. these will deflect the heat up. then put your mat down then best to put self levelling compound over the mat. it ensures the cables are fully encapsulated in cement and prevents damage to the cable. then it would be ok to tile.

 

[babyblog]

thanks for that advice Mike...appreciated

 

[Daz]

I would just contradict the advice from Mike slightly. As I understand it, cement boards do not add any strength to a floor (Mike has not stated that they do, by the way) but they do not provide any thermal properties either.

I would suggest that you ensure there is no deflection (bounce) in the floor and then use cement lined insulation boards such as Wedi or Marmox instead. They will give you much better UFH performance.

 

[grumpygrouter]

I'm with Daz on this one.

 

[White Room]

Daz does better

 

[DHTiling]

And to add more, if using insulation boards then min thickness should be 10mm on a timber floor
They need to be embedded in a flexible adhesive but as above the original floor needs to be solid

Oh and 6mm ply is a no no


Sent from my iPhone using Tapatalk

 

[Mike]

I would just contradict the advice from Mike slightly. As I understand it, cement boards do not add any strength to a floor (Mike has not stated that they do, by the way) but they do not provide any thermal properties either.

I would suggest that you ensure there is no deflection (bounce) in the floor and then use cement lined insulation boards such as Wedi or Marmox instead. They will give you much better UFH performance.

i stand corrected if there's no thermal properties in the hardi boards. i was led to believe there was. but i did say the floor has to be solid before the boards are laid as i know they add no strength. cheers

 

[Gazzer]

Actually they do have some thermal properties just not as good as insulation boards.

 

[babyblog]

so once i have secured the floor and made sure it is solid....i can put down the insulation boards screwing them down as well as with adhesive....does this give enough strength and stop movement in the floor and for the tiles ??....so they don't crack or move ?....thanks for all the advice so far....much appreciated...

 

[Stewart]

You need to eliminate all movement in the sub floor. Once you've done that then the insulation boards glued and screwed will give you a perfect floor to install your heat mat and tile...

 

[babyblog]

that's bang on....thanks for the advice...