" foil backed ply " please help!!!

[MattMoore]

Hi all,
im hoping someone here can help me, im about to be laying down a under floor heating source in a customers bathroom,
the customer has been speaking to her friends about it, and she has this idea that they have foil backed ply as the
subfloor to lay the flooring mats down onto, and then tile over. i can see it being quite a practical idea,
but i havent been able to find any where who sells the stuff!!
im after 4 of 18mm 8 by 4 sheets.

Cheers

Matt

 

[MikeW]

Hello Matt,

I have not heard of using a foil-backed ply. The couple I did for a friend's home were electric "pads" that were in turn buried in concrete and tile laid on top.

Here are two links to look at. The first is what I am referring to. The second is a resource of links.

http://www.diydoctor.org.uk/projects/un ... eating.htm

http://www.ebuild.co.uk/web-directory-p ... p?pid=PHEA

Regards, Mike

 

[RogerS]

The ply is intended to form a better, more 'even' surface and often used where the underlying floor isn't particularly flat. Especially if you are going to lay tiles over the top. This helps stop cracks appearing between the tiles later on.

Foil backed would be, I guess, an attempt to reflect heat back up...sort of similar to those fil backed panels people are told to stick behind their radiator. Not convinced of the benefit IMHO...

 

[MattMoore]

on this particular bathroom, it is more or less going to be a wet room, so we are having to build a raised floor, with a slight taper into it so that the water will drain away, i have searched high and low and havent been able to find anything, i figured that it would be just to reflect some of the heat back into the room,
the only thing i have foind was ply foil, which seemed to be a very very good insulation, but that was just a roll of the insulation, no boards!

thanks for the responses so far

Cheers
Matt

 

[Chris Knight]

There appears to be some stuff called radiant barrier roof sheathing that is foil backed ply http://tinyurl.com/c3abs This is a USA based product, possibly sold over here.

 

[tim]

Matt

Try this link:

http://www.warmup.com/uk.phtml

See' the backer insulation boards'

I laid a floor for a customer and they had this stuff already as part of the underfloor heating kit. More like a polycarbonate (prob similar to Chris' suggestion).

I don't think that they are the only stockists but I think this will do a better job than ply.

Cheers

Tim

 

[jasonB]

I've always laid the electric UF heating onto marine ply or Aqua panel never seen a foil backed one. Some of the wet systems use a metal reflector that the pipes are laid into to reflect the heat.

Are you using a tanking system such as BAL WP1 or taking a chance that the grout will keep the water in

Jason

 

[ProShop]

IMHO, the foil backed ply is pointless, as heat will rise naturaly.
It certainly works for plasrterboards on ceilings and walls and foil behind radiators (I can vouch for the effectivness this gives), but not underneath ply flooring. :shock:

The ply will need some serious sealing against water ingress especially in a wet bathroom. I had a customer some time back who had a similar setup, when I ripped up the floor to investigate for the insurance companyto see what had happened the ply had completely delaminated.