Underfloor heating questions

[Flintstone]

I nearly always just go for 200w because, well why not ?

 

[Uheat - Jake]

Thanks @pdc

Your best option in such a small area is to take a 160w/m2 or 200w/m2 as the cost difference between mats at the small sizes is so marginal its cost effective to future proof incase you want to remove the rad in the future.
I'd also recommend either a 6 or 10mm Backerboard down first as well to help reflect the heat and stop any heat escaping downwards.

And finally, give us a shout for a quotation. Forum members receive extra discount.

 

[Dan Ryan]

Thanks for all your replies on the heat mat, you're right it just gets up to heat quicker. How about the fixing - glued and screwed is that just for timber or for cement as well?Reason being if its cement I might be able to save depth with less adhesive below insulation.

 

[Waluigi]

Glued only.

 

[Dan Ryan]

Even more confused now. So the insulation boards should be just glued down and not screwed?I thought originally they were meant to be laid on a bed of adhesive.What I am a bit concerned about is that say the finished floor after its all installed is at 30mm I then have to match this with new carpet and underlay in a adjoining room.If I reduced the total height of the installation without reducing the quality of the work it's be great.

 

[Dumbo]

Glued means use adhesive . As regards height it is what it is . It's function over form . After a while you won't notice the height difference and wonder what the fuss was about especially if you fix a purpose made threshold out of timber to accommodate the difference . But if your ufh doesnt work properly it will always not work properly and you won't get over that .

 

[Andy Rhodes]

Dan I would bedded the insulation boards on a 6-8mm flexible adhesive bed mechanically fix the boards down then with the fitting that go with the boards which you can get from the company that supplied the board the UFH matting normal has a sticky side which isn't all the great so I would use a stable gun to hold down the matting but nowhere near the heating wire as you only what to hold it in place until you've screed over the matting with a levelling screed by doing this you with optimise the full function of your UFH , as it will distribute the heat equally all over the floor making it most cost efficient to heat

 

[Uheat - Jake]

If you're going onto a screed you can use the XPS Insualtion boards.

We recommend these are stuck down with a 2mm bed of adhesive. These don't need to be mechanically fixed as there's no bounce on a solid concrete floor. Mechanically fixing is only really used with Timber subfloor.

 

[Dan Ryan]

Aha yeh you meant tile adhesive , I'm not up with the terminology!

What total build height do you think I'm looking at?

I'm also thinking of using carpet shims and thick underlay when the carpet gets replaced to make up some of the height difference to the finished tiled floor.Last thing I want is to have a proud threshold that we keep tripping over.

 

[Uheat - Jake]

The usual build up is around 18-20mm before tiles. You normally have the following,
2mm adhesive bed for insulation
6mm insulation
4mm heating mat
6-8 flexible slc