Does a strip foundation need to be insulated?

Hello everyone,

we have a floor slab with a strip foundation and the ETICS only goes halfway up the floor slab. Now, it is generally said that the insulation should go 80cm below ground level. My site manager says that, given our soil structure, this is not necessary and no thermal bridge would occur. He said that there are specifications about how deep cold affects the building and that this would be sufficient. Is there anyone here who can confirm this?



The curing layer is not an insulation curing layer, but a normal stone.

I am a bit torn because on the one hand the site manager has explicitly planned it this way, but on the other hand it is said that you have to insulate all the way down.

Hi,

these things are usually regulated in an energy saving ordinance calculation. If your drawing is correct, and you have no insulation beneath the floor slab, I claim that the missing ISO fillet is already a mistake. Whether the insulation has to be pulled down 80 cm, I do not want to judge here. I believe this statement is not generally valid, but the "safe way." From a personal feeling, I would have extended it further down as well, but I can only give you a technically based statement after I have properly inquired.

But it is clear to me that the cold from the ground anyway penetrates the masonry through the reinforced concrete (whether floor slab or foundation) and you will have a problem there in my opinion.

You write "The site manager planned this" - Is the site manager an architect? Who is doing the planning?

All I can say is, if this planning were submitted to me in my function as site manager, I would have issued a notice of concern.

Best regards, Jann

Such nonsense, a thermal bridge is always created. Either the detail complies with DIN 4108 Supplement 2 and equivalence is demonstrated in the Energy Saving Ordinance/Building Energy Act proof, or the thermal bridge is calculated. Even category A according to DIN 4108 Supplement 2 extends 50 cm into the ground, even if no ETICS is used. Excerpt from PSI-Therm equivalence proof.