Plasterboard Condition Ok?

I’m new to this but I’m really enjoying the step by step guides - very clear. I’m almost ready to have my first go on a real wall but I’m a little concerned about the condition of the wall as it stands.

It’s a plasterboard wall and I’m planning on just applying a skim coat so I understand that suction shouldn’t really be a concern. However, the plasterboard is fairly old and there are a number of damaged areas. I’ve stripped some pretty thick wallpaper and removed a dado rail which was held on with adhesive. As a result, the top layer of paper has peeled off in certain locations. I wouldn’t say the plasterboard core is exposed (apart from in very small areas) but the paper is pretty thin at points. I’ve tidied it up to a certain extent but I wonder if the condition will cause me problems. Should I do the suction test and use PVA if necessary or would I be best to apply a base coat first – or perhaps even replace the plasterboard?

I’ve attached a photo of one the worst areas. Any advice would be much appreciated.

Many thanks,


Hi William

All the problems with the plasterboard you describe can be easily sorted with PVA. Whilst it will help to control the suction, the main reason for using is as a bonding agent - to ensure the paper on the plasterboard is properly bonded and sealed, as well as ensuring the plaster will properly adhere.

2 coats of PVA
1st Coat
The first coat of PVA needs to be very thin. It is hard to give specific details as different brands vary so mix water with the PVA until it becomes like a skimmed milk consistency. When the PVA is thin it can penetrate further into the paper. If it is too thick it will just lay on the surface. Pay particular attention to the damaged areas.
2nd coat
The second coat of PVA can be thicker - (a similar consistency to gold top milk) As this PVA dries and becomes tacky scrim tape can be pushed into it in areas where the paper is thin. This will provide additional strength. Then plaster as normal.
Potential Problems
All may go very well but sometimes the paper may have lost its bond and blister. They can be small blisters or quite large. If at any time in the PVA or skimming process this happens then a small incision with a knife needs to be made so that a thickish coat of PVA can be worked into the blister to allow it to be stuck back. Then continue as normal.

It will be a lot easier to do this rather than have to apply a base coat or re-plasterboard.


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