ᐅ Grooves/Cutouts in aerated concrete for KfW 40 standard

Created on: 30 Apr 2021 08:16
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Markus254
Hello everyone,

In our shell construction (aerated concrete 42 cm (16.5 inches), KfW 40 standard), recesses for water connections, drains, downpipes, etc. are being built into the exterior walls. How deep/wide can such recesses usually be made before it becomes critical from a structural or energy-efficiency perspective?

Thanks and best regards
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nordanney
30 Apr 2021 10:54
Markus254 schrieb:

What about concealed cisterns? 60cm (24 inches) wide, 14cm (5.5 inches) deep in a 42cm (16.5 inches) wall.
What is the alternative? Surface-mounted installation covered with drywall (plasterboard).
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Nordlys
30 Apr 2021 12:38
Just as a side note for control freaks: you usually hire a masonry company because building houses is their profession, and you don’t leave it to a do-everything-all-in-one service that claims “nothing’s impossible, cash on the spot.” We never asked ourselves the above-mentioned questions and simply let the professionals do their job.
Musketier30 Apr 2021 12:55
Nordlys schrieb:

Just a side note for control freaks. You usually hire a masonry company because their profession is to build houses, and you don’t hand that over to some all-around service that says “nothing’s impossible” and demands cash upfront. We never questioned the above issues and simply let the people do their job.


Just because it’s a masonry company doesn’t mean everything is automatically fine. I shudder when I think of our plastering company. Not only did they go bankrupt afterward, but they probably contributed significantly to the general contractor eventually having to throw in the towel, as he had to deal with legal disputes and warranty claims. Just the damage in our case was likely in the five-figure range.
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Markus254
30 Apr 2021 19:39
Nordlys schrieb:

Just a side note for control freaks. You usually hire a masonry company because building houses is their profession, so you don’t let an all-in-one, do-it-all service handle it without question. We never questioned the above concerns and simply let the professionals do their job.

That’s true. We’re satisfied with that as well. A little supervision never hurts 😉
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Markus254
30 Apr 2021 19:40
nordanney schrieb:

What is the alternative? Adding a frame and covering it with drywall.

An alternative would have been a facing wall (made of Ytong).