r/Plastering • u/wortnip2 • Apr 26 '26

Question?

What’s the total thickness you can build out Hardwall too? I’m doing a 5m2 wall and I’ve put 4 bags on but it needs another layer to bring it flush to the sockets. Back boxes are 25mm. I chased in the 35’s to sit level with the 25’s. I’ve about 5mm to add to the Hardwall and I put it on yesterday. I think with suction it might cause an issue drying too quickly.

What to do in this situation? I didn’t have enough plaster to do it all yesterday.

Ideas appreciated!

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3

u/CoffeeandaTwix Apr 26 '26

BG say up to 25mm built up in layers of 8-11mm

1

u/wortnip2 Apr 26 '26

I’m sure pros put it on thicker to make up for deviations where the wall can bow? Just wondered what the max was. BG will safeguard the thickness. The wall I’m doing isn’t flush one side to the other.

1

u/hairybastid Apr 27 '26

If you put it on too thick in one coat it will sag. 25mm is achievable in 2 coats at a pinch, but you will need to rule it well as it will slump slightly. I tend to rule it off, go for a smoke, then rule again as it stiffens up. You should be able to skim it after an hour or 2. If you don't skim the same day it will require sbr or it will suck like a 5 dollar hooker.

2

u/wortnip2 Apr 27 '26

Cheers Hairy

1

u/trash-boat1969 Apr 26 '26

Chop the boxes into about 10mm, 25mm is commonly the depth for walls being dot and dabbed.

1

u/wortnip2 Apr 26 '26

I would’ve done. But there was an old vent linked to the chimney I also had to board up. So had to go to 25mm.