Screed too high above underfloor heating

Good evening

Following situation

We had a floor heating system installed by a company
According to the data sheet, the Schlüter Bekotec system requires the screed coverage over the studs to be between 8mm and 25mm.

So far so good

Now a screed company was hired to lay the screed.
After consultation between the heating company, screed company and even an employee from Schlüter,
the screed was installed at 45mm over the studs.

What now?
Is it possible that my floor heating cannot heat my apartment?
How can I find a solution to the problem?

So we also have knobs in which the water pipes run and about 50 mm of screed on top, and there is absolutely no problem with heating up. 8 to 25 mm I find quite low, isn't that unstable?

So we also have studs in which the water pipes run and about 50 mm of screed on top, and there is absolutely no problem with heating.
8 to 25 mm seems really low to me, isn't that unstable?

OKay our system is similar, but even there we have no problem with heating the living spaces, they all reach their temperature. However, I actually find our nearly 50 mm already too little.

For the distances, I also consider 8-25mm far too little. The heat does not dissipate well with that. As a rule, you also have a minimum overlap of 45mm.

Hello questioner. The system "Schlüter Becotek" is basically designed for the renovation of old buildings, in which a floor heating system must still be taken into account with predetermined build-up heights. Usually, with conventional warm water underfloor heating systems, we have to calculate with a build-up height of at least 60mm, which we mostly do not have in existing buildings. The system from SCHLÜTER in question here requires only about 8mm above the heating elements due to coordinated materials and system components. Why this works, I do not want to go into here as it would go beyond the scope. But it has been working for many years. Now, the system-related heating pipes also have a diameter of 16mm. At least that is what the corresponding data sheet says. So what happens if more than 8mm of screed is applied as an overbuild? Well, this increases the thermal resistance. The amount of heat calculated by the planner is thus inevitably used to heat up the screed mass. This causes at least inertia of the system regarding the speed of the current heat demand. How should one proceed further? Well, this is by no means legal advice!! Nevertheless, I would formulate a written complaint of defects (this must absolutely be on the letterhead!) by registered mail to the responsible party (is it a general contractor or did you award the order for the screed installation yourselves). What I do not understand: If the heating system was specified with about 8mm over the studs of the SCHLÜTER system panel, then the screed applied with greater thickness causes the entire usable level to be higher now. With all the problems of forced height points at stairs and doors. However, this is an aspect that you must check yourselves, as otherwise the process would be too specific for a public forum like this, tailored to a specific construction project. ------------------------- Regards: KlaRa