Under Floor Heating ???

[manwithmission]

Hi

I want to put underfloor heating in my bathroom.

I've been told that, in order to avoid the tiles popping, I need to take up the 18mm Ply.

I already have enough 18mm MDF to do the job. Is MDF just as suitable?



Thanks
Ian

 

[Jasonb]

Don't use MDF.

Are you sure you have 18mm ply and not chipboard?

Is the ply straight onto the joists or overlaying an old floor?

Are there noggind under the board joints?

Need to know the above as 18mm straight onto joists can be a bit flexible.

Jason

 

[manwithmission]

The T&G floor boards are still down at the moment.

It's just that I have 3 full sheets of 18mm MDF & only one sheet of 18mm Ply. That's why I asked about the MDF.

I plan to put noggins in & cross members between the joists.


Out of interest, why not MDF?


Thanks
Ian

 

[Jasonb]

Assuming your MDF is standard grade and not moisture resistant or exterior grade it will be too unstable in the humid atmosphere and if it should get wet will swell to double its thickness. You will also be hard pushed to find a floor tile adhesive thats suitable for MDF.

Take the T&G up and replace with 22-25mm WBP ply with noggins under the joints, its cheaper than risking a failure of the floor.

Jason

 

[manwithmission]

Thanks Jason

Will do!

What's "WPB" ply btw?


Thanks
Ian

 

[gcol]

Hope Jason does mind me jumping in here - just trying to save the poster some time. WBP stands for Water and Boil Proof - basically, exterior grade ply.

 

[manwithmission]

Aha! thanks

Do B&Q sell this?


ta
Ian

 

[gcol]

Yes they do.
For general tiling info, have a look at the tiling sticky at the top of this forum.