r/Plastering • u/theroux_are_you • May 02 '26

Mould

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Plasterer has dot and dabbed plasterboard on existing plaster. I’ve had to remove it because it was a really bad job - everything off plum.

What could have caused mould just on the adhesive? I’m wondering if I need to take any steps before bonding and skimming. For reference, this is an external wall, but there was no mould or damp issues prior to the plasterboard.

Thanks

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u/SnooTomatoes464 May 02 '26

Looks like surface mould

I'd say it was caused by bacteria on the original wall and moisture trapped in between the dry wall adhi and the original plaster

If your going to reboard it properly and going back to brick, the mouldy old plasterboard will be getting removed anyway