Use of PVA

[Jupiter01]

Hi,

I am getting mixxed messages on the significance of PVA when having my walls skimmed. I should add that in some cases, the skimming is taking place on eisting plaster and in other cases, on fresh plasterboard sheets.

I've got some plasterers telling me that the walls must be PVA's 3-4 times before skimming and others suggesting that one coat is sufficient.

Can anyone shed some light on this please?

Thanks in advance.

 

[rochester plasterer]

Just one coat of pva is enough. Pour it in a tub with a roller put a splash of water in it and mix it. It shouldn't be to runny and shouldn't be to thick. Just creamy. No need to pva plasterboard the boards are designed for multi finish plaster to go straight on. A good tip is to add food colouring to pva so you can see where you have/haven't been

 

[roughcaster]

. A good tip is to add food colouring to pva so you can see where you have/haven't been

Exactly, especially when putting PVA onto a white/light surface. I use red food colouring. Another thing, always skim onto the pva while it's wet/tacky. If it dries too quickly, just roll on some more.

 

[Ambergreen45]

I know a lot of Pros apply 1 coat of PVA on existing masonry, which is probably sufficient. Personally, though a bit more work I follow the instructions on the tin, and apply 2 coats on high suction backgrounds (plasterboard being excluded), the first one to seal and once dry, a second coat which needs to be sticky to the touch before plastering.

 

[rochester plasterer]

If I pva'd a wall and went the skim it a few days later I would give it another coat of pva. But if plastering the same day I would just do 1 generous coat.

 

[Jupiter01]

Thanks guys. That is very helpful. Much appreciated