Hardi backer boards

[Ian]

Tried to find some data but can't find much. Can they be used as insulation boards? I know that marmox boards can be used specifically for this purpose but wasn't sure about the hardi's.

Thanks Bri

 

[DHTiling]

Hi Brian..

Sorry but nope they are not for insulation purposes..

 

[Aston]

hi bri
there not that good for insulating....you will need wedi, marmox, schluter board etc for good thermal qualities..

ed

 

[Ian]

Thought so, thanks folks.

 

[The Legend; Phil Hobson RIP]

As above Brian, Wedi, Marmox etc are insulation boards Hardie, no more ply etc. Are cementitious backer-boards

 

[Gazzer]

You could read this
http://www.tilersforums.com/electric-underfloor-heating/43599-insulation-boards.html

 

[Ian]

You could read this
http://www.tilersforums.com/electric-underfloor-heating/43599-insulation-boards.html

Thats alot of numbers! I think I'm more educated now!

 

[Gazzer]

Thats alot of numbers! I think I'm more educated now!

I think this actually made it easier for me to understand
However, in real life comparisons with cable underfloor heating the following approximate results were observed:

1. Onto bare concrete slab – took about 3 hours to reach max temp of 24°C.
2. Onto No More Ply 6mm – took about 40 minutes to reach 24°C and 3 hours to reach max temp of 27°C.
3. Onto Beavaboard 6mm – took about 30 minutes to reach 24°C; temperature 29°C at 3 hours and still increasing.

 

[tim_r]

Do any of the insulating boards have the strength of hardi backer? Is it best to use both when overlaying a wooden floor to have UFH and then tiles?

 

[Ian]

Do any of the insulating boards have the strength of hardi backer? Is it best to use both when overlaying a wooden floor to have UFH and then tiles?

Hardi boards aren't used to add strength, just a suitable surface to tile on. If the subfloor is not stable the hardi boards won't cure the problem.

 

[aph257]

I would get the strenght from WBP ply (25mm) then add the insulation board.