Thick Underlay for Wooden Flooring

[Harin Vaghela]

Hi all,

First post on here but this forum has helped me on many occasions with its useful information, advice and of course general banter!

I am in the middle of a large house extension and renovation and it seems my builder and the glazing company have got their wires crossed and what I thought would be a flush threshold on my 6 metre wide sliding doors now has a 15-17mm step which i didn't want.

The floor is split since part of the floor is the original house and part is of the extension. The new part has underfloor heating while the old is floorboards. At the moment the floor is level but just 15-17 too low.

So the question i wanted to ask is is there a material i can use to bring up the height of the floor without compromising the underfloor heating? I am currently looking at 18mm thick engineered flooring but I'd need to raise the floor by another 15-17mm somehow. Would I be able to double up on the fibre underlay boards? If not are there any other materials I can use would raise the height?

Thanks in advance.
Harin

 

[Doggit]

Sorry, am I right in thinking that it's the new extension with the underfloor heating that's too low, and this is the part that will have the engineered wood floor on top of it, or are you doing the engineered flooring in both the old and the new floors.

If you double up on the fibre underlay, then you might be reducing the heat transmission. Can the builders add liquid screed to the floor to bring it up to the required level.

 

[Harin Vaghela]

Hi, Thanks for the response.

Well the whole floor is too low but yes the extension side has the UFH. And yes the whole floor is having engineered flooring.

Will the screed cause any loss of heat do you think?

 

[Doggit]

Okay, if the whole floor is too low, then you need to bring both sides up. You already have a concrete screed floor in the extension, and a liquid screed is just very wet concrete mix that will settle nicely. But the builders could just build the existing concrete screed a little higher. It should be okay, but discuss it with the builders first. Obviously it'll take a little longer for the extra screed to warm up.

You need to start with the wooden floor, and first lift the floorboards, then fix 18mm strips to the top of the joists, then fix the floorboards down. Then you bring the extension side up to the new level.

Who's fault was it.

 

[Harin Vaghela]

Thanks! I think I'll talk to the builder about that liquid screed to bring up the new part of the kitchen. And I think he mentioned putting plywood on top the the floorboards so will probably do that.

Not really sure whose fault it is but am waiting for the glazing company to get back to me. Not too worried now there is a solution and after thinking about it its better than the finished floor level being higher that the door threshold!