Insulation of the ground floor / if applicable, underfloor heating

Hello!

We want to insulate the floor of our ground floor in autumn. We have a house from 1921 with a vaulted cellar, which is not insulated. Insulating the cellar ceiling is not an option, so we are doing the floor. We have been living here for 3.5 years and it is too cold for my feet in winter, plus it is also required by regulations. We will start with the living room this year and then do the rest step by step. The cellar temperature is constantly 14°C, but we want to tackle this to save even more heating costs (the rest of the house is well insulated and we consume very little heating energy).

We want to insulate as effectively as possible since we are making the effort. The current structure is: laminate, old linoleum, probably OSB underneath, planking, wooden beams in slag. All of that will be completely removed. I quite like the floor system from Fermacell, the new floor should be light and doable by ourselves. The raw ceiling would need to be primed, bonded screed applied, then a rigid insulation material, and then the dry screed panels. Afterwards, I imagine a nice cork parquet or something similar.

Has anyone here had experience with the above-mentioned structure? Or generally with bonded screeds? Are there other ideas for floor insulation that can be done as DIY?

Also, we currently only have a gas heating system. Underfloor heating in the living room would of course be nice but is not a must. The existing radiator heats the living room completely sufficiently at present.

Looking forward to input!

Insulating the basement ceiling is not an option

Why?

besides, it is also a regulation

No, it is not.

The current structure is: laminate, old linoleum, probably OSB underneath, floorboards, wooden beams in slag.

First clarify the correct structure. Concrete ceiling and the assumed structure on top? It also depends on the height you can realize.

Besides, we currently only have a gas heating system. Of course, underfloor heating in the living room would be nice, but it’s not a must. The existing radiator currently heats the living room completely sufficiently.

Underfloor heating cannot heat more than adequately either. Planning underfloor heating for only one room, however, is total nonsense. Planning effort, hydraulics with mixer, etc., cost-benefit ratio...

Because then the basement becomes too low and we would have to insulate all the electrics and other lines there, which would only be a patchwork and a real hassle. Whether it is actually mandatory or not doesn’t matter, because we are insulating it for ourselves and not for the authorities. Besides, at least in the kitchen the beams are ruined (sagged) and we want to lay tiles there later, as well as in the hallway.

What should I clarify about the construction? Everything is going to come out anyway. Opening it beforehand is not an option, the house is inhabited and we want to keep the construction period as short as possible. We definitely have no concrete anywhere. From bottom to top there is a vaulted cellar (barrel vault), slag, wooden beams, original simple boarding, OSB, linoleum, laminate. From OSB to linoleum it is from the previous owner. Whether we end up building up 17 or 20 centimeters is also not crucial with a bound fill as I have in mind. Since we installed rather expensive interior doors on the ground floor, the construction will be oriented to their height.

The underfloor heating would then of course be for the entire ground floor, but we are doing one room at a time. And as said, it is also not a must and we would only implement it if it was relatively easy.

At this point it is about the reconstruction.

Whether it is actually mandatory or not does not matter, because we are insulating for ourselves and not for the legislator.

Then you didn’t have to write it and now answer snappily ;-)

What am I supposed to clarify about the construction?

If you know the construction and the possible height, everything is fine. Just please don’t get upset if in the end 3 cm are missing for the underfloor heating because you planned it roughly.

The underfloor heating would then of course be for the entire ground floor,

If of course, then write that and not "in the living room we would like to have underfloor heating if possible." It is relatively simple at least not. Whether it makes sense depends, for example, on the possible insulation under the underfloor heating. But for that, you also have to know what space you have or what build-up height.

Wasn't meant to be snappy, sorry!

I roughly know the possible height because we can see at the basement staircase how much space there is up to the ground floor level. So up to the original floorboards, you can see that from the side there. But of course, there is a vault and I don't assume that it was built to the same height everywhere in 1921, the thickness and height will surely vary here and there upwards, but of course we'll only see that once we've actually removed everything.

With a dry construction floor buildup, the height should work with underfloor heating. But that's something I would clarify with the plumbing company beforehand, they are very competent. However, that's really just a side question for us, we can live well without underfloor heating and would rather see it as a luxury bonus.

It's an old building and a renovation. Usually, you only see what you're working with once you've stripped everything bare. We're used to that. You often have to replan or buy more, but that's just how it is. Therefore, I'm not interested in detailed planning - we can only estimate that once the room is open up to the raw ceiling. What matters to me is basically bonded filling, experience values, etc. :)

Basically, it will be a "usual" dry construction, for which there are many possibilities. A underfloor heating system is certainly feasible in terms of the assumed height but it is questionable whether you want that. For example, we do plank flooring without underfloor heating in the new building. I think you should first make the fundamental decision regarding underfloor heating just as well as at least somewhat the type of the later covering. Depending on the decision, you can then, for example, choose a beam layer and any insulation between and on top of that OSB plus final covering and much more. There are also good underfloor heating solutions for this type, especially for do-it-yourself. What you then take as insulation is ultimately more a question of the desired insulation standard, the desired material, and the price. With that, you can calculate back and forth as you like. Also decisive will probably be (as with me) what you prefer to work with; for me, for example, loose fill is less so. I found the Steicofloor system quite interesting, several providers offer that. But there is also something from Bauder for upper floors with OSB on top, I could even imagine that. If it is too cold for your feet so far and it is anyway an older house, I could also imagine solid wood planks for aesthetic reasons, and as mentioned, there are underfloor heating solutions for those that have already been shown here.