ᐅ Interior walls made of Poroton or calcium silicate bricks?

Hello,

As a basic rule, I’ve always heard that you shouldn’t mix materials. So if the exterior wall is made of Poroton, the interior wall should be too.

However, for the interior, different bricks are used anyway—not the T9-14 bricks you use on the exterior wall, but rather the so-called hollow bricks. These have much more mass and you can drill and fix things into them normally. We have T14 bricks for the exterior wall, which requires good fasteners (though still standard ones) and careful drilling. Our kitchen wall cabinets are hung on normal fasteners on the exterior wall. No issues at all.

Important: be aware that unenforced Poroton bricks provide poor sound insulation compared to calcium silicate bricks. With a T8 brick, you should ideally have very quiet neighbors. We have a T14 brick with 16 cm (6 inch) external thermal insulation composite system (ETICS), which, in my opinion, is already borderline. If I were to build again today, I would either use only the heavy Poroton hollow bricks or go straight for calcium silicate bricks.

Best regards,

Andreas

Alessandro schrieb:

Otherwise, the entire brick will come right at you

Well, it’s not that bad, but you definitely shouldn’t use a hammer drill for this. Unfortunately, very few tradespeople seem to know that—or they simply don’t care because hammer drilling is obviously faster. So, if in doubt, you need to watch out for it yourself.

I know the search function here isn’t exactly user-friendly, but having a handful of interior wall threads every year isn’t really necessary either. Eventually, everything has already been said multiple times.

andimann schrieb:

I’ve also always heard as a basic rule that you shouldn’t mix materials.

Basically yes, but this rule dates back to the time of small-format bricks, which were mortared thickly rather than thinly bonded (and where, by the way, the interior walls were still built in the same work phase). Or as my late Uncle Alex would have said: back then, we had an emperor.

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Alessandro schrieb:

Don’t worry too much about that!
I have a 75" TV, including a 5kg (11lb) wall mount, hanging on an 11.5cm (4.5 inch) Poroton wall. Nothing happens!
I just used standard wall plugs for that.

I didn’t ask for more, but some people tend to overinterpret. Thank you for sharing your experience with the 11.5cm Poroton wall.

We have KLB blocks on the outside and calcium silicate bricks on the inside. Our construction company said this is for better sound insulation. I can confirm that when the doors are closed, you barely hear anything. What really bothers me about the calcium silicate bricks is that you can’t get a nail in them at all! I wanted to carefully nail our baseboards, but every single nail either breaks or bends. I’ve tried everything! In the end, I glued everything and sometimes drilled holes. Also, every small decorative item or picture has to be attached using a drill and wall plugs. With KLB walls, you can just hammer in a nail and the picture stays up. How is it with Poroton?

Steffi33 schrieb:

Our exterior walls are made of aerated concrete blocks and the interior walls of sand-lime brick. Our construction company said this is for better sound insulation. I can confirm that with closed doors, you hardly hear anything. What really annoys me about sand-lime bricks is that you can’t get a nail in! I wanted to carefully nail on our baseboards... every single nail either breaks or bends. I’ve tried everything! In the end, I glued everything and, if necessary, pre-drilled holes. Also, each small decorative item or picture frame has to be installed using a drill and wall plugs. With the aerated concrete block walls, you can simply hammer a nail in and the picture will hang. How is it with Poroton?

Thank you, this also helps me a lot with my decision-making.