Floor slab with integrated underfloor heating. Disadvantages? Costs?

Hello everyone, does anyone have experience with a slab foundation for a single-family house with an underfloor heating system integrated into the slab? The providers on the internet naturally advertise this as a miracle solution. But are there any serious disadvantages to this system besides the possible price difference compared to a conventional slab foundation with screed and underfloor heating?

Thank you for your answers
bg
Till

Hello Till,

Besides the advantage of time savings, I essentially see two disadvantages.
1. The heating is even slower than a conventional underfloor heating system in the screed, as significantly more material (concrete) has to be heated up.
2. Since the insulation layer under the screed is missing, there is no way to lay cables or water pipes over the floor slab, which are then covered by the screed.

I think both systems have their justification and have advantages and disadvantages.

Regards

Stefan

Hello Stefan,
Thank you for your assessment. I had also suspected the inertia, and the point about the pipes is very convincing to me. What I am still wondering: are the insulation boards used permanently able to withstand the pressure of the material resting on them?
Best regards
Till

We have one of those so-called climate floor slabs. And it’s great!!!

At first, we planned a conventional floor slab, then the house builder said he had already worked a few times with the company Futura using the climate floor slab. I then dealt with it for a long time and gathered a lot of information. But we ended up doing it with another provider who was 4000 euros cheaper, who in turn works a lot for Futura since he comes from the industrial floor sector.

It is important that the excavation contractor does a clean job during the earthworks, meaning the fine grading must be perfect; just being able to operate an excavator is not enough. The insulation boards were prefabricated in the hall for the perimeter formwork, resulting in fewer joints than most others who order the finished edge boards. My heating installer then laid the underfloor heating, installed the distribution cabinet, built in the shower channel for the level-access shower, and set the drainage points. It is important to already know where which interior wall will go because there is no turning back, and you don’t want to drill into the heating pipes later if you want to anchor something in the floor, and a wall on top of the heating makes no sense either. We painted the interior walls on the insulation boards with spray paint for good planning.
After that came the reinforcement and the concrete, which was then smoothed, done in no time...

What was important to us was that we didn’t need screed anymore, to bring as little water as possible into the house.

You could lay tiles/laminate directly on the floor inside.

We need less heating temperature than at our neighbor’s house with the conventional floor slab because ours stores the heat more and releases it more specifically. There is no noticeable difference in inertia compared to the normal floor slab or our old apartment from the 80s. On the contrary, the floor simply doesn’t cool down as quickly as usual, and no heat is lost unnecessarily downward anymore.

So we are very satisfied and the costs were the same when considering the subsequent screed with the conventional slab.

But pay attention to the provider; there are many "wannabes" who think anyone can do a few insulation boards and smooth over some concrete… What’s important is a proper execution, for example, for the installation of exterior doors and floor-to-ceiling windows and as few joints as possible in the fiber cement edges. (With the conventional one, you usually have one every 50 cm).

Another advantage is the load distribution, which is no longer punctual but nicely spread out…

For the next house, it will definitely go in again =)

Since May 2012, we have had a Futura Energiesparbodenplatte installed in the ground floor of our new building and a "normal" underfloor heating system under 7 cm of screed on the upper floor. Since moving into the house in October 2012, we have experienced the following:

If you set the room thermostats in all rooms to the same temperature and the heating is set to a room temperature of 23 °C, the rooms on the ground floor with the Futura floor slab warm up very slowly and do not deliver the required heat output. You can set a higher temperature on the heating system (e.g., from 23 °C to 25 °C), but this leads to higher energy costs since the flow temperature must be higher. I assume this is due to the heat losses caused by the approximately 20 cm more concrete between the heating pipes and the floor surface, which also needs to be heated.

Another disadvantage: The Futura Energiesparbodenplatte heats very sluggishly. You cannot "quickly" make the bathroom warmer. On the upper floor, on the other hand, the temperature increase is noticeable within 30 minutes due to the "normal" screed underfloor heating. On the ground floor (Futura), it takes about 6 hours until you feel the warmth on the floor. This disadvantage also negatively affects children's rooms because you cannot quickly reduce the temperature by 1-2 °C in the evening before going to sleep.

I cannot recommend the Futura floor slab for living spaces.

Dear Hauke,

Thank you for your opinion. I am sorry that you are not satisfied with the heating performance of the FUTURA EnergieSpar floor slab. Unfortunately, we did not discover your post in this forum earlier.
Since we cannot find your name in our records, I would be pleased if you would contact Mrs. Dipl.-Ing. Carolin Schneider (Quality Assurance) at our company. You can find the contact details on our website. I am confident that we can help you resolve your issues as quickly as possible, as our standard is always the highest possible quality.

Kind regards
Dipl. Ing. BDB Sven Foht (Managing Director FUTURA Fundamentsysteme GmbH)