Drinking water pipes directly under heating pipes (underfloor heating)

Hello everyone,

the plumbing guys have partially laid cold water, hot water, and the circulation line on the raw subfloor of the upper floor in our new building.
As can be seen in the pictures, all pipes, except for the brine pipes of the heat pump, are wrapped in red 4mm thick insulation, although I don’t know if it’s just meant as pure mechanical protection.

The 3cm impact sound insulation does not additionally cover the pipes, so the plastic pipes of the underfloor heating lie directly above the impact sound insulation and a thin foil. According to my research, there should be at least 13mm of insulation around the drinking water pipes.

My concern is that especially in winter the underfloor heating warms my cold water so much that it does not remain permanently below 20°C but maybe even rises above 25°C. That’s where, for example, legionella tend to thrive.

In the attachment you will find a few pictures. Would you not see it that strictly or should the insulation at least directly under the underfloor heating meet the minimum thickness? So far there is only the underfloor heating, without screed. It would still be associated with manageable effort.

What am I entitled to if the plumbing professional comes up with arguments like "Oh, nothing will happen… we always build like this… the 4mm is enough… we simply put a bit of edge insulation strip between the drinking water pipes and heating pipes…”?

Many thanks in advance for your help.

Regards
Tito

hmm well it's nothing big... but as always first question beforehand: What was ordered?

What do you mean by "what was ordered? I have a contract with my builder and he in turn had the sanitary items tendered. There is also an in-house architect on board who is in charge of the construction management. The fact that I report defects to him several times a week and question things, etc. says it all. But that is not the topic...

Goes somewhat off the question, but in my opinion the space between the pipes should be filled with a bound bulk material so that a flat, load-bearing support for the screed is ensured everywhere (ideally in the form of a separating layer). If your photos show the final condition before underfloor heating/screed, that would not be correct in my opinion.

By what was ordered, I mean what is stated there: What type of floor construction did you order? There is an execution plan with sections and drawings indicating how the construction must be. These are signed before construction and can be followed thereafter.

I cannot judge if there is too little installation height in between. If that is botched, it should be done properly. In winter, the cold water is colder than in summer, so it could balance out with the heating. It is clear that the standing water warms up, but in summer, when the floor is also 20°, it is not different with standing water. Legionella are only a problem if the water stands, meaning no cold water is drawn. I consulted three plumbers about this topic (2 acquaintances, the third from the company that installs this) and the architect, all said the water would have to stand for at least a week before something forms (with the note that this statement does not necessarily hold true in theory).