Engineered wood and underfloor heating

[Coolhurst]

is there a engineered board thickness best suited to use with UFH? Was thinking 21mm but someone mentioned that size would limit heat transfer so c.15mm is better. Are there any rules?

 

[crazydaze]

The thinner the board, the faster the heat transfer, most reputable manufacturers will have specific guidence with regards suitability and tog ratings, this applies to underlay products as well. There are a number of specialised underfloor heating underlayment products that designed to help the heat efficiently.

The underfloor heating system will also have very specific guidence with regards to floorcovering layers that are suitable for install above their product, the last thing you want to do is overload the heating system.

Essentially you need to match your floorcovering to your underfloor heating system.

 

[WoodYouLike]

The thinner the board, the faster the heat transfer,

Depends also on the backing used, so thinner is not always better.

But you're right about matching the two and to follow both manufacturers instructions/guidelines what can be used on UFH

 

[woodfloordesigns]

I fully agree with all comments. If you use a 20mm then the heat will get through but it will take longer. Once there its the same. Do not forget that you must not exceed 27 degrees c at the interface between the wood floor and the sub floor.

 

[mointainwalker]

@WFD

Can you please expand on your comment about the 27 C ?

If it's a technical limit then it will differ with manufacturers, will it not ?

 

[woodfloordesigns]

In our terms and conditions we specify that there should be sensors set within the surface of the floor to cut of the system if it goes above 27 degrees. 27 degrees is the optimum level at which oak ( I know oak best) and many other species achieves a balance with the atmospheric humidity within the room above the flooring. This humidity needs to be 45% -60% and can be maintained at this by keeping house plants well watered and vases of flowers topped up. The outcome of not maintaining this balance is that the top layer of the floor will try to shrink. As it is engineered the sub layers restrict this and as a result the floor may crack .If it cracks vertically this is only a visual problem and can be filled. If it cracks horizontally then this becomes a "shake" which is considerably more trouble. It is all to do with not drying the noble layer too much.
This is not as daunting as it sounds, just get it right in the first place and give your floor and incidentally yourself a healthy environment.

 

[mointainwalker]

You may require this for your wood, but by doing so, you are limiting the heating function.

The statutory limit on the floor surface for health reasons is 30 C ( or poss 28 , don't recall ) and by imposing your limit , you are significantly diminishing the W/m2 output.

If you are selling branded product, is this something you are stipulating over and above the MI's ?

 

[WoodYouLike]

The statutory limit on the floor surface for health reasons is 30 C ( or poss 28 , don't recall ) and by imposing your limit , you are significantly diminishing the W/m2 output.

28 degrees is what our manufacturer of the duoplank states to be the maximum surface temperature (Oak range of duoplank is guaranteed on UFH, if the UFH is used correctly of course).

To be honest, never heard of the "interface" temperature limit, and contradicts with the max surface temperature if this interface limit is lower or same.

 

[woodfloordesigns]

These are standard requirements and conditions throughout the wood flooring industry. Check with any wood flooring manufacturer and you will get the same temperature requirement +/- 1 degree.

 

[woodfloordesigns]

"Interface" is where the wood and the subfloor come into contact and is the same max surface temperature of the subfloor

 

[WoodYouLike]

Used the wrong word in my reply - contradicts.
That's not the case, if the interface temp max is 28 degrees (- / + 1) the top surface temp can never be the same, but is lower.

 

[mointainwalker]

@ wfd

Just looked at Tarkett who simply say max 27 C without saying where. Here however is an extract from Kahrs UK - fitting instructions over UFH.

The surface temperature of the finished floor must never exceed 27°C at any point. This also applies under rugs, etc., and furniture. Provided that rugs are not too thick, or there are...........

They are quite clear- and quite clearly contradict what you claim -and it certainly cannot be the case that 27 C at floor interface is

standard requirements and conditions throughout the wood flooring industry. Check with any wood flooring manufacturer

as you wish to believe. Can you quote

any wood flooring manufacturer

who specifies this interface temperature ?

 

[woodfloordesigns]

NWFA BWFA TRADA

 

[mointainwalker]

Are any of those wood-flooring manufacturers ?