Underlay to suit underfloor heating

Curious Geroge

There are a lot of threads on this but there does seem to be a difference of opinion between what is best. I'm putting in a 10mm ac4 laminate from Krono on holicore with underfloor heating. The irish supplier of Krono flooring is Canadia who have recommended Tuplex Underlay for underfloor heating but there website states this is an acoustic underlay. What have people used recently?

http://www.canadia.ie/index.php/products/product/tuplex-15m-1.1m-3mm-110002

bigalk

"Canadia who have recommended Tuplex"

(NOTE: i have edited my comments below as i hadn't realised the Tuplex product is 33 square metres - so its not crazy expensive as i had previously surmised. That said, i still stand by my comments below that this is not the right product for the job and you will get a better U value with both specialist products, or your bog standard 'white foams')

they are recommending this because they sell it. Admittedly it has a OK TOG rating of 0.83, but in reality this is a specialist moisture management underlay designed to pump out damp air from underneath the floor. Why on earth they would recommend that you spend a load of € on a moisture management product is beyond me.

For the heating aspect the main thing you need to look at is the TOG rating or the K-m2/W rating. 1 TOG = 0.1 K-m2/W.

Manufacturers will tell you that anything below 1 TOG is suitable, but those same industry guys will tell you that an underlay with a 1 TOG rating provides good insulation. So which is it lads??

Im also an industry guy and i recommend you try get below 0.5 TOG - and there are plenty of products out there that will reach those low levels, but at a price. For instance a specialist product will cost you about €4.50 per square metre.

Second consideration is the product itself - you could put down a few layers of newspaper at no cost, which will have a TOG of 0 - but are you going to do that? Most likely no.

Google "underfloor heating underlay ireland" and you will find an irish site with a full section of underlays below 1 TOG. . You can get a specialist product 0.35 TOG for €37 + VAT. Does the Tuplex make any sense now?

The Tuplex is a compromised product (from a wear and tear point of view) due to the fact that it is designed to deal with moisture.

The 3mm bog standard white foam they sell - which most likely has a lower TOG than the Tuplex he recommended is marked as "This is not suitable for use with under floor heating - please see our Tuplex underlay". Ill bet you 5 internets that the 3mm foam they sell has a TOG of less than the Tuplex, but they dont want you to know that -they want you buy the expensive stuff. Ask him for a TOG rating on it for the craic, or to clarify their position.

Curious Geroge

The local hardware shop does the Canadia range and 90% of the underlay sold for underlay is comfort silver underlay. Not too sure of the brand though; Tog is 0.5. The next best I found is Quicktherm or Isoheat which both have a 0.35 tog. The flooring company has given me a name Thermaflow Acoustica underlay with a 0.22 tog value.

bigalk

any of the above are 100% suitable - coming in around 0.5 TOG or below. Ill be honest here - i have reservations about the Thermaflow Acoustica specs. Its a 3mm rubber underlay with what looks like a fleece backing and I just cant see how that ties up with any other 2mm or 3mm rubber underlay that have MUCH higher thermal resistance. It just doesnt add up for me.

That said you can only take them at their word so Ill see if i can get hold of a proper data sheet on it and will post a link here if i do.

BarneyMc

Any updates from anyone on this? I'm buying laminates from 2 suppliers. One has suggested not using the 'white stuff' as it, over time, packs into nothing and the laminate then rubs against the screed floor underneath. The other says the white stuff is fine but can supply an 'acoustic' underlay at a higher price.

I probably should get a full spec on both but in the meantime has anyone any more info?

bigalk

BarneyMc wrote: »

I probably should get a full spec on both but in the meantime has anyone any more info?

Yes you should!

Basically:
1) Dont use white foam unless you cant afford anything better. Its U value is good (should be below 0.5 TOG) but for a good quality / long life install you can do much better for not a lot more money.
2) Get the lowest TOG underlay you can afford - make sure it is less than 0.5 TOG
3) As above, and having had some communications with them (they never sent the test sheets no matter how many times i requested them) I dont believe the specs from FloorWiseGuys (Thermaflow Acoustica Good), but do your own research, maybe Im just being cynical.

Bad_alibi

Got quoted €33 a roll for Trojan perforated underlay for UFH, 12.5m/roll with a tog of .44
2mm thick, 30kg compression and I think 22 decibels soundproofing.

What are people's thought's on this. Good or bad deal

Bad_alibi

Any thoughts on this need to pull the trigger in the next few days

Bad_alibi

Bad_alibi wrote: »

Got quoted €33 a roll for Trojan perforated underlay for UFH, 12.5m/roll with a tog of .44
2mm thick, 30kg compression and I think 22 decibels soundproofing.

What are people's thought's on this. Good or bad deal

Last call.

cocoa123

Folks, what TOG do I need for concrete subfloor/8mm laminate flooring without underfloor heating? I was thinking of 2.15 Tech boards with 2.15 TOG. Is this OK? I might need also some poly-film against moisture? Would 1.4 TOG polystyrene foam with foil backing suffice? TOG is lower, but moisture barrier is built in. Sorry, I complete newby in these things.

kisugem

Best I found for UFH is vista warm.
0.2 TOG only
20db soundproofing.