How thick is the plaster wall?

[Autodidak1]

If it's a fire cell between you and your neighbor, it should be double 15mm fire-rated gypsum board with fire sealant between layers, and there should be metal at the joints.. you can't just make holes in that wall however you want...

A fire-resistive wall can look many different ways. In apartments/semi-detached houses, it's uncommon to have double fire-rated gypsum unless it's a high-rise building.

But the construction is determined by the requirements, and if you want thinner walls, you can have thicker/more boards or of higher quality.

Even plywood + gypsum is approved depending on the classification and wall construction.

 

[A-Man_08]

This is probably classified as a high-rise building, I would think.
It doesn't seem to be that critical, I'll drill another hole and push in whatever is at home, plug or expander.

 

[Borgir]

This is probably classified as a high-rise, I would think.
It doesn't seem to matter much; I'll drill another hole and use whatever I have at home, either a plug or an expander.

over 4 floors = high-rise..

 

[Autodidak1]

over 4 floors = high-rise building..

4 floors require fire protection class 4 (60 minutes) and do not require fire protection gypsum in all situations. Depends on the frame construction etc.

 

[A-Man_08]

I took what suited best from what I had at home.
I didn't have the right screw for the brown plug, so I used 2 montage screws 4.2mm in a red plug in 5mm holes. The screws were tight and good.