ᐅ Properly insulated floor with underfloor heating (15–16 cm build-up height)

Hey everyone

First of all, I have to say this is a really great forum. I’ve been reading for a while, but now I have a question myself.

How would you build a properly insulated floor structure with underfloor heating? The total build-up height including the floor covering is 16cm (6.3 inches).

It’s about a ground floor over an unheated basement.

I originally thought there were 18cm (7 inches) planned for the floor build-up on the ground floor, but in the heat of the moment, I overlooked that the architect planned only 15cm (6 inches).

What can I say? The windows and doors are installed, some of them floor-to-ceiling. That means I have to make do with 16cm (6.3 inches) measured on site.

Are there any possibilities to optimize this? The screed has to be at least 65mm (2.6 inches) thick (20mm (0.8 inches) underfloor heating pipes + 45mm (1.8 inches) screed cover).

In an extreme case, if necessary, could insulating the basement ceiling from underneath be an option? Would that make sense?

I hope you can help me out here.

Best regards,
Chris

Why do you have to do that? If someone made a mistake, they should provide the solution.

Apart from that, yes, it is possible to insulate the basement from below, but it probably won't be necessary.

First of all, thanks for the reply.
Well, it’s not really a mistake. The architect simply calculated with 15cm (6 inches) buildup. I thought it was 18cm (7 inches) on the ground floor and 15cm (6 inches) on the first floor and attic.

The plan shows 15cm (6 inches). So it’s because I overlooked that and now it has been executed accordingly.

The architect says 15cm (6 inches) is enough. Now I just want to get the best out of it.

Best regards, Chris

19Chris84 schrieb:


The plan includes 15cm (6 inches). So it’s because I overlooked that, and now it has been built that way.

The architect says 15cm (6 inches) is sufficient. Now I just want to make the best out of it.

Best regards, Chris

Then there should be a planned floor structure for the 15cm (6 inches) that should fit, right...?

Hello,
Was the underfloor heating planned from the beginning? Your architect should be able to answer that question.
We added underfloor heating in the basement during the construction phase and only had 15 cm (6 inches) available.
Instead of the usual 6 cm (2.5 inches) of insulation under the underfloor heating, we used 3 or 4 cm (1 to 1.5 inches) of some material that insulates better—don’t ask me the name. Then 3 cm (1 inch) of hook-and-loop board with pipes, 7 cm (3 inches) of screed, and 1.5 cm (0.6 inches) of laminate including impact sound insulation. That adds up to about 15–16 cm (6 to 6.3 inches).

Best regards,
Andreas

Above all, the energy performance certificate must be in order.