ᐅ The plaster has come loose around the channels cut for wiring.

Created on: 18 Jul 2023 23:05
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Hunsrückblick
Hello, I visited my construction site today full of anticipation, but since then I have been a bit concerned.
What could be the reason for the plaster detaching from the wall? It surely can’t be caused by the chasing alone, right?
Exposed red brick wall with two insulated water pipes (hot/cold) mounted on a bracket.
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sysrun80
18 Jul 2023 23:24
It seems there is no liability at all. That's surprising.
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HilfeHilfe
19 Jul 2023 06:45
Ufff...... the house is already falling apart.
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chand1986
19 Jul 2023 06:56
There are also bonding primers for plaster. Ask which one was used here.
kati133719 Jul 2023 07:25
Hunsrückblick schrieb:

It’s a gypsum plaster, as far as I know. No idea exactly what type. I sent a defect report to the company today and hope they don’t have to remove everything...

I would actually hope they take it all down. I can’t say what causes this either, but I wouldn’t want to hang a picture later and have a chunk of plaster the size of a sandwich throw itself at me.
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Buchsbaum
19 Jul 2023 08:05
Most likely, no primer was applied to the wall, and the plaster, as it is often said, has been “burnt.” In other words, the plaster lost its water too quickly (due to the absorbent Poroton), preventing it from forming a proper or any bond with the wall.

A primer or bonding agent prevents this. Always treat Poroton blocks with it beforehand.

You can test this yourself by simply pouring a glass of water on the Poroton. It absorbs the water immediately. That’s exactly what happens to the plaster. It dries out before it can bond to the wall.

No reinforcing mesh was embedded, which I would have done especially with gypsum plaster. But that is a matter of personal preference.

However, as you can see, the installer already hammered on it quite a lot. Still, the plaster should not come off so easily and without residue.
Hunsrückblick19 Jul 2023 08:36
Buchsbaum schrieb:

Most likely, no primer was applied to the wall, and the plaster was, as they say, "burnt." This means the plaster lost water too quickly (due to the absorbent Poroton), preventing it from properly bonding with the wall.

A primer or bonding agent prevents this. Always treat Poroton blocks with it beforehand.

You can test this yourself by pouring a glass of water on the Poroton. It soaks in immediately. The plaster experiences the same—it dries out before it can bond with the wall.

Also, no reinforcing mesh was embedded; I would have especially used it with gypsum plaster. But that is a matter of opinion.

However, as you can see, the installer already hammered on it quite a bit. Still, the plaster shouldn’t come off so easily and completely without residue.
Thanks for the info. Is the use of a primer specified in any regulation or standard?