Underlay for laminate floor over underfloor heating

Pangur

Has anybody got any advice as to the best type of underlay to put under laminate flooring with underfloor heating. My head is wrecked trying to get to the bottom of it all!! Is the 2mm foam the best for getting the heat through from the screed?

Jill

Looking for the answer to this question also

CJhaughey

2mm underlay is fine, you can't stop the heat coming up.
Make sure that you use a Polythene barrier between the foam and the screed.

Jill

Hi CJ

What is a polythene barrier and how much does it cost?

Waht are the thoughts on laminate v's engineered with underfloor hearing ?

Thanks

CJhaughey

Polythene sheeting doesn't have to be thick just has to cover the entire floor area under the timber.
I think I paid €20 for a huge sheet of it, enough to do the entire ground floor 100m2 or so.
I think that all wood flooring will be OK especially if it is allowed to acclimatise to the room first and the longer you leave the screed to dry with the UFH on the better.
I have solid 20mm red deal and it hasn't moved much at all

hjsimpson

2mm cork underlay is the best for underfloor heating.
The concrete must be < 4% moisture for either laminate or engineered (semi-solid).
Current thinking is that unless you are very lucky you will have trouble with most solid floors over underfloor heating.
Depends on whether you dont mind losing coins or small children down between the boards when the heating is on in winter and the boards have contracted.
There are some lovely engineered floors out now that fully resemble solid floors, random lengths etc so why take the risk?
oh and dont forget the 500g polethyne under the cork.......

Bar29

I,m in the same boat now and thinking of using a 2mm cork underlay with underfloor heating - but i'm just wondering why you would suggest to use 500g polethyne under the cork...isn't this primary a moisture barrier which surely isn't necessary with underfloor heating...??

hjsimpson wrote: »

2mm cork underlay is the best for underfloor heating.
The concrete must be < 4% moisture for either laminate or engineered (semi-solid).
Current thinking is that unless you are very lucky you will have trouble with most solid floors over underfloor heating.
Depends on whether you dont mind losing coins or small children down between the boards when the heating is on in winter and the boards have contracted.
There are some lovely engineered floors out now that fully resemble solid floors, random lengths etc so why take the risk?
oh and dont forget the 500g polethyne under the cork.......

Carlow52

the poly is belt and braces in case the concrete is damp

corboy

So with engineered boards and underfloor heating, is it better to glue it down or float it on cork for the best heat results???

Carlow52

jason.baptiste wrote: »

Yes, with underfloor heating, it is better to float it on cork for the best heat results.
A laminated flooring installation isn't affixed to the sub-floor, you need a good quality padded underlayment to dampen sound, add to the stability of the floor, give warmth and add a more comfortable feel underfoot. Some manufacturers pre-attach this underlayment to the planks. While this is a convenient option, some experts view attached padding as slightly less effective than a separate underlayment. The underlayment usually consists of cork, felt or foam. Laminate floors mimic the warmth and texture of real hardwood accurately at a fraction of the cost. The new, glueless laminate flooring click together designs are a terrific home improvement project. These floors can be lifted and replaced easily, partly or room-wise.



_________________
Greentech are specialists in a range of Underfloor Heating Services.

First post on Boards on a 7 month old post with an advertising link

Im my opinion, material like cork timber laminates etc are not suitable for putting on top of underfloor heating due their poor thermal conductivity
http://en.wikipedia.org/wiki/List_of_thermal_conductivities

The smaller the number, the poorer the heat transfer and the less responsive the underfloor heating will be plus a greater need for much more insulation below the underfloor heating
from the link
cork 0.04
Concrete 0.8 [ 20 times better than cork]

If you understand the issue of heat transfer across numerous layers of materials with different thermal conductivities then proceed accordingly.
Keep warm

gsxr1

Carlow52 wrote: »

First post on Boards on a 7 month old post with an advertising link

Im my opinion, material like cork timber laminates etc are not suitable for putting on top of underfloor heating due their poor thermal conductivity
http://en.wikipedia.org/wiki/List_of_thermal_conductivities

The smaller the number, the poorer the heat transfer and the less responsive the underfloor heating will be plus a greater need for much more insulation below the underfloor heating
from the link
cork 0.04
Concrete 0.8 [ 20 times better than cork]

If you understand the issue of heat transfer across numerous layers of materials with different thermal conductivities then proceed accordingly.
Keep warm

what would you suggest? Glue down? I have done this in customers home with great results on new builds. With solid timber. Floor is lovely and warm to the touch.





interesting link that. once i got my head around it.

Carlow52

gsxr1 wrote: »

what would you suggest? Glue down? I have done this in customers home with great results on new builds. With solid timber. Floor is lovely and warm to the touch.

interesting link that. once i got my head around it.

Thanks for kind words: here is another link http://www.hukseflux.com/thermalScience/thermalConductivity.html
which is reference 5 in the first link.
The values for cork and concrete are a little different but the relative difference is the same.

For the full 9 yds see here:
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

On a recommendation, don't have one as I am old school on this subject, dont like UFH as an idea, much prefer the in wall solution.

However if you have had success with solid timber glued down then I am pleased.

The values for wood shown here http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

support your experience.

I just got into this post when I saw cork.

As is clear from the science, the poorer the thermal conductivity, the greater the delta T required to extract the heat from the UFH to get a sufficient response in a reasonable time

SergeyLee

Hi Everyone!
I am new to this forum and to the whole issue of underfloor heating (pls forgive my ignorance of the technical terms you were using!). My question is less just abt what underlay to use, but is it worth doing at all. I am building a conservatory and wanted to install an electrical underfloor heating as an expensive but convenient heating system. Now my wife wants to have a laminate flooring in the conservatory. In a flooring shop I was told that due to its (poor?) thermal conductivity if I lay laminate on top of the electrical heating I will not get an efficient heating system. I now have doubts whether to spend a grant on UFH (which may not give us efficient warmth) or argue with my Boss to replace laminate with tiles or carpet (neither of which she likes...).

Can anyone give me their real life experiences abt efficiency of UFH with laminate and would it be worth spending money? Will such things like underlay, etc. make a significant improvement to the efficiency?

Thanks in advance for your help!
Sergey

bigalk

Hi all,

I own a wholesale flooring accessories business, trading for 13 years.

Of late some underlays have been coming available on the market that have a very low tog rating. this is the only property of the underlay you need to look at.

we currently sell a wood flooring underlay with a tog rating of 0.35 (Quicktherm) and a 7mm carpet underlay with a tog rating of .08 (Everspring Eclipse). you really need to be under 1 tog to let as much heat through as possible.

the tog rating is its ability to block (insulate) heat / or let it through. the lower the tog rating the better it will perform with underfloor heating

go into your local flooring / carpet store and ask.

MOISTURE LEVELS ARE CRITICAL FOR SOLID AND MOST ENGINEERED FLOORS. ALWAYS HAVE A MOISTURE TEST DONE BEFORE INSTALLING THESE TYPES OF FLOORS!

mr_edge_to_you

Does anyone know of any suppliers of cork underlay? This is a very confusing topic but I initial discussions with trade professionals is that cork is the best underlay material for UFH. Recommendations by PM please.

bigalk

RE Cork Underlay.

Cork underlay is one of the better types of underlay for use with Underfloor Heating. My stats bring in a 2mm cork at about 0.5 TOGs and above. As far as i am aware this is a pretty

there are other more efficient (specialist) products out there - as low as 0.3 Togs, but you will have to do your own homework as to whether there are any savings to be had on the price of cork V's specialist types. and if there is a trade off on those savings over the life of the product!.

MOD - sorry to be bumping old threads - but each time i see a Boards.ie result in a google search i usually pop in to help clarify any unanswered questions or wrong info. please feel free to snip at will.