We are planning on insulating an levelling the floor in our extension which was made in the 60s. The floor is concrete with tiles on top. We are planning on putting down a DPM then 100mm Kingspan Thermafloor TF70 with another layer of vapour barrier and then lay 16mm UFH pipes and 32mm liquid screed which should leave us with 13mm to lay tiles on top for the utility room. Total thickness we need to achieve to be level with the suspended floor in the next room is 145mm. 

 

The suspended floor in the next room is the where it gets a bit tricky. The airing bricks are just open into the extension and will presumably need to extended. 

 So the question is, how do we do that with the least need to breaking up the old slab, or perhaps we don't need to do that at all somehow? And then, how do we connect the extension so the external walls in a good way?

 

Attached are a couple of pictures of our utility room and our lean to/ conservatory, the floorplan with red drawings on how I think the 3 air bricks needs be extended, and the technical drawing from Kingspan that I think suit our situation.

 

Any thoughts on how can do this?

Kingspan Thermafloor TF70  has a k-value of 0.022 W/m.K.

So 0.1 m will have a U-value of 0.22 W/m².K.

In today's terms  and energy prices, that could make it quite expensive to heat the area. This does depend on how large it is, what the losses are for the space, how often you heat it and what flow temperatures you use.

 

As you are considering digging up the floor, probably worth doing some proper costings to see what is best.

 

On 22/06/2024 at 18:26, SteamyTea said:

Kingspan Thermafloor TF70  has a k-value of 0.022 W/m.K.

So 0.1 m will have a U-value of 0.22 W/m².K.

In today's terms  and energy prices, that could make it quite expensive to heat the area. This does depend on how large it is, what the losses are for the space, how often you heat it and what flow temperatures you use.

 

As you are considering digging up the floor, probably worth doing some proper costings to see what is best.

 

That is a fair assessment but the amount of work with ripping out the old pad, the subbase under it and the pour a new pad is a lot more work than doing what I describe above and also much more costly, I'm not sure that the extra insulation added will ever be worth the investment. What it would likely enable though is a presumably easier routing the extension for the airing bricks, that solution is really what I would love some help/examples with.