Underfloor heating - which option is best for the perfect project?

Good evening everyone,

we are in the rough planning phase for our house renovation and would like to have underfloor heating installed.

We have read into various topics, watched YouTube videos, and compared different manufacturers as best as possible.

Currently, there is a design floor installed on the ground floor (not basemented). This will be removed because some walls still need to be built. The energy consultant has also been on site and recommended insulation of the floor slab to reduce heat loss due to the lack of a basement. We would of course comply with this.

Now we are faced with the decision whether to use a dry screed system, which we could partially install ourselves, or a system with liquid screed, which must be carried out by a professional company.

The room height of 3 meters is sufficient, even with a classic underfloor heating system with approximately 9 cm build-up height.

We currently also prefer a dry screed system because we can save enormous costs here.

Has anyone already had experience with such a system and can give a brief feedback?

We are very happy about this.

Thank you very much in advance.

Hello, I don't really believe in such a large cost saving. Screed is not really expensive. Dry screed requires a suitable substrate. For example, we have done dry screed in the attic due to the low construction height, but there is no heating installed there at all. Our floor is solid wood and therefore very even and well suited for dry screed.

If I were you (since you also seem to have enough construction height), I would install plenty of insulation including tack foil as a DIY job. The underfloor heating pipe can also be laid on it as a DIY job. First, have the heating load calculated room by room and the installation plans created by the energy consultant, plumber, or engineering office. Then start according to the plan and possibly initially get additional professional support or have it checked.

"Normal" cement screed, by the way, is far from liquid, so rather very dry. At least I was surprised since I didn't know that before.

Also here again the note:
Installing underfloor heating yourself and stapling it releases the screed layer installer and plumber de facto from any guarantee.
Every damage will be blamed on you because, as a layman, you did not staple the pipes correctly or stepped on them in such a way that fine cracks of course had to develop.

For services that were not carried out yourself, it is logically impossible to assume any guarantee.

The savings, on the other hand, are minimal. A professional installs underfloor heating for 150m² including insulation in 1.5 days; they get the material significantly cheaper than you... Nonsense.

Laying underfloor heating yourself and stapling de facto releases the screed layer and installer from any warranty.

We already discussed the topic and your nonsense in the other thread. The installation is done by the heating engineer. He usually also takes over the warranty. That’s standard practice.
If you do it all by yourself, it’s naturally your problem – although with continuous installation the risk is very low. Have you ever seen screed layers at work? Given how much they walk over the pipes all day long (duration and intensity), you simply cannot manage that during the installation time.

And the screed layer has nothing to do with it. He takes care of his trade, not that of the heating engineer.

The saving, on the other hand, is small. A professional installs underfloor heating for 150m² including insulation in 1.5 days, he gets the material significantly cheaper than you… Nonsense.

How high is the saving? How much cheaper does he get the material (and why)? Please provide numbers so that the original poster can get an assessment.

But let’s get to the OP’s questions.

We currently also prefer a dry screed system because we can save enormous costs here.

What calculations have you made so far that lead you to an enormous cost saving? So how would the floor be newly built in each case and what costs have you calculated for both variants? Removing old screed or just laying over it in the dry screed variant?

A remark regarding the price: If you remove the old screed in both variants, the wet system is probably about half as expensive. Very roughly calculated. You can check the online shop material costs to get an impression. For 150sqm stapler system (stapler insulation board, pipes, staples, edge insulation strips) you reach about €2,000. Then there’s the screed at about €3,000. The same as dry system about €9,000. Then the screed boards come on top. Let’s reckon €5,000 versus €10,000. All very rough, without heating circuit distributor, small parts, and labor (except for the screed layer installer).

Has anyone here experience with such a system and can give a short feedback?

No, not with me personally. So far I have only used the classic variant in new builds and renovations – both through craftsmen and completely DIY (except for the screed layer, the screed layers just do it better and faster at that price).

...
If you do it all by yourself, of course it's your problem - although with continuous laying the risk is very low. Have you ever seen screed layers at work? The way they walk over the pipes all day long (duration and intensity), you simply can't manage that during the laying time.
...

These are important and good questions from Please answer as completely as possible ;) And it's really like that, you think no stone will be left on another afterwards given how they stomp around. I seriously had to hold myself back from making comments to them.

It doesn't matter at all what screed layers do. If you laid the pipes yourself, YOU have to prove that nothing went wrong. The installer also just says, "Everything was fine during the pressure test, but that means nothing. Hairline cracks or poor clamping can also lead to damage later." Or you might have accidentally bent a pipe too tightly ;) There are hundreds of ideas that come up as to why the self-performer is also solely to blame.

It's like with an oil change. If you did it yourself, no manufacturer on this planet will give you a warranty or goodwill on an engine damage because it is generally assumed that you, as an amateur, did something wrong, for example used the wrong oil or overfilled it, or whatever. Nobody gives anything away, especially not in construction ;)

Apart from that, it doesn't even save you a thousand because you pay more for the material and it also takes longer. Just figuring out as a layman how to lay out the rooms so that everything fits in the end.

Good luck.