ᐅ Underfloor heating in a concrete slab – advantages and disadvantages?

Mycraft schrieb:
A surface heating system, which includes underfloor heating, primarily heats through radiant heat.

Surface heating, yes, radiant heat—that’s debatable. The heat primarily develops through convection of the air.

Your comments about our system are probably correct—the new house will have a masonry stove, and the warmth feels like sunlight. Of course, that depends on personal preference.

Full agreement @Mycraft Someone gets a faulty underfloor heating system installed, and then underfloor heating is considered bad... Anything other than a surface heating system in a new build has to be very well justified.

However, the original poster was referring to a Swedish panel; it’s a complex topic and the overall concept has to be right.

haydee schrieb:
Was your underfloor heating installed in the screed or in the concrete slab?

The underfloor heating is installed in the screed.

Thanks for the link, Haydee! I wasn’t aware that “Schwedenplatte” is just another term for it.

@hampshire then your underfloor heating is not installed directly in the concrete slab. A tiled stove is a really nice feature – but you have to think about adding wood every day, so it’s something to carefully consider if you don’t want to deal with it daily.

With underfloor heating embedded in the concrete slab, my biggest concern is that any potential repairs would be very complicated – much more so than with underfloor heating installed in the screed.

Behind us, a Swedish timber house with this kind of panel was built last summer. What I saw was very well done. First, the ground was carefully leveled and compacted, then squared off. Thick Styrodur panels were laid down, followed by a steel framework, then pipes and conduits, another layer of steel, and everything was poured in concrete. The concrete was smoothed out very thoroughly. Basically, nothing can get damaged there since nothing will move anymore. I would have little concern about that.

However, when the Swedish panel manufacturers claim that traditional floor constructions have worse insulation, I’m still not convinced. The traditional setup uses steel-reinforced strip foundations, with steel-reinforced concrete poured between the strips, on which the walls stand. Then, a thick layer of bitumen waterproofing membrane is hot-welded on as a moisture barrier. On top of that, thick insulation is applied, followed by pipes, conduits, etc. Finally, a floating screed is installed. This is also a proven, warm floor structure. The only downside is that it takes longer due to the drying time of the screed.

Thank you, Nordlys! Have the neighbors moved in, and are there any initial feedback on the heating system's efficiency?
(My second concern is that a lot of heat might be "lost" through the concrete slab.)