Low Suction

[OhGranny]

Hi Everyone
Can someone help me understand the term 'low suction?'
I have some plasterboard to skim and I am confused as to what is meant by the term. To me it suggests a surface that wont suck much moisture out of the plaster i.e. low but surely cardboard will dry plaster quickly!
Is it not high suction?
Thanks Help a numpty today !!!!!

 

[Richard C]

Can someone help me understand the term 'low suction?'
I have some plasterboard to skim and I am confused as to what is meant by the term. To me it suggests a surface that wont suck much moisture out of the plaster i.e. low

Spot on.

but surely cardboard will dry plaster quickly!
Is it not high suction?

The term is relative to the rate of absorbtion of other building materials you will come across. The lining paper on PB (& the Gypsum plaster sandwich) will absorb moisture fairly quickly but it’s not very thick so will also reach saturation point quickly; compare it with, say, Thermalite blocks which are very high suction & engineering bricks which would have a lower suction than PB.

 

[OhGranny]

Thanks
Explained now, so I take it no need to use any PVA or dampen the board surface down before starting.
Thanks
G.

 

[PrenticeBoyofDerry]

If you plastering over plasterboard no prepping needed, other than applying tapes to the joints that is, so straight on with the plaster finish.

 

[Richard C]

Normally not necessary to PVA boards before skimming but if you do it won’t hurt; it will give you a bit more time if a novice as will using Multi instead of Board finish.