UFH mats and Hardie backer board

[RDTiling]

Hi all

A customer has a 4m2 bathroom floor, which has floorboards down at the moment. They are fairly solid, so just a few extra screws into the joists to make 100%.

They have asked me to quote both with and without UFH, (first time I've been asked to lay UFH).

Im looking to overboard with 6mm Hardie backer board, but my question is do I also need to add a thermal board like Marmox or can I lay the UFH mat directly onto the hardie, cover with SLC and then tile?

Thanks,
Rich

 

[Qwerty]

I personally would forget the hardi and lay insulation boards instead. Fix with bagged cement tile adhesive then lay out the UFH on top of that. SLC over the lot to encapsulate it all then when dried tile away. Don't forget to check the UFH resistance before, during and after. I always use a UFH alarm for peace of mind

 

[Sean SML Tiling]

Hardie will be fine

 

[Qwerty]

Hardie will be fine

Yes, Hardi will indeed be fine. Out of interest what would be your reasons for choosing Hardi over Marmox? Always interesting to hear differing opinions on this. I'm a Marmox man through and through and used to fix Hardi all the time.

 

[RDTiling]

Thanks for the advice guys.

Two different answers to get to the same end result! - I'll price it both ways and see which one come out cheaper for them.

Good shout about the resistance checks - looks like contents of my tool chest is about to increase again! Any recommendation on which resistance checkers to purchase? Or are they all as good as each other?

 

[RDTiling]

As I only started tiling in June/July I've so far only over boarded with ply but I'm looking to only start using cement boards from now on.

i was always under the impression that insulation boards were only there to prevent downward heat loss on a solid substrate like concrete, which was why I initially thought Hardie plus insulation board as it was floor boards. Good to know though that I don't need both though and this another thread I'll print down for my 'noobie' manual!

 

[Qwerty]

I changed to Marmox as it is cheaper, available in varying thicknesses, cheaper, easier to cut, has superior thermal properties and a lot lighter!

As for brands of multi meters...... they pretty much all do the same job. Find a decent cheapish one from Toolstation or similar and you will be fine.

Don't forget to fit sensor cable when laying the UFH, and mark on a scale diagram where the wires are

 

[RDTiling]

Top-advice as always Geoff - many thanks and it's very much appreciated.

 

[Stef]

I changed to Marmox as it is cheaper, available in varying thicknesses, cheaper, easier to cut, has superior thermal properties and a lot lighter!

As for brands of multi meters...... they pretty much all do the same job. Find a decent cheapish one from Toolstation or similar and you will be fine.

Don't forget to fit sensor cable when laying the UFH, and mark on a scale diagram where the wires are 

Geoff, where are you getting your marmox boards from?

everywhere ive looked its always more expensive than Hardie.
i used wedi in my own downstairs bathroom (6mm) & my only dislike about it was when kneeling to tile the floor my knee would leave a dent where i had been.

 

[Qwerty]

Geoff, where are you getting your marmox boards from?

everywhere ive looked its always more expensive than Hardie.
i used wedi in my own downstairs bathroom (6mm) & my only dislike about it was when kneeling to tile the floor my knee would leave a dent where i had been.

Tilefix direct Stef

http://www.tilefixdirect.com/category/marmox-tile-backer-insulation-boards

I always use an off cut of Marmox on top to prevent denting

 

[Qwerty]

Here is the type of monitor alarm that is handy.....

http://www.ebay.co.uk/itm/like/3507...ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=102

 

[RDTiling]

I always use an off cut of Marmox on top to prevent denting 

The simplest of tiling tools! It's only when someone says something like this you think 'oh yeah....why didn't I think of that'

I'l get both an alarm and multimeter ordered....both handy things to have.

 

[Sean SML Tiling]

Yes, Hardi will indeed be fine. Out of interest what would be your reasons for choosing Hardi over Marmox? Always interesting to hear differing opinions on this. I'm a Marmox man through and through and used to fix Hardi all the time.

Just nobody stocks marmox by me but I used marmox a few times and I do think its a better product.

 

[Ajax123]

As bathrooms are considered "special areas" under part p of the building regs and you are not a "competent person" under the regulatory guidance you should not technically be installing fixed wiring systems without the involvement of either building control or a "competent person" who can certify the work under the regulations. If this doesn't happen it is technically an unlawful installation. In itself this is not an issue unless there is a problem with the floor e.g. A fire at which point you could find yourself in some strife.

This is always a concern of mine when hearing about underfloor heating systems in kitchens and bathrooms.

How do most tilers deal with the issues created by part p

 

[Qwerty]

Final connection made by certified electrician