PVA and plastering.

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neat!? i was told NEVER neat as it dries like plastic which is a less than ideal surface for plastering onto.
 
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To be fair when we've used it neat we have never had any problems.

If your taught one way you tend to stick (parden the pun) with that unless someone else tells you any different. I think thats why so many peolpe get confussed or misslead when doing something
 
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1 & 1 to 2 & 1 for second coat of pva, then skim when tacky, 4 & 1 first coat.
 
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i agree Jab actually, i think everyone has been taught different things and carrys on doing those things without question, there HAS to be some science to this and i'm DETERMINED to find out the REAL TRUTH to this matter
 
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RIGHT THEN!

Scoured the net and found a BBA certificate for Unibond plastering PVA, BBA are the people who certify products as suitable for the building trade according to British building regs and here's what they say:

primer coat on absorbent backgrounds of 1:5 which is allowed to dry, followed by a 2nd coat of 1:3, plastered onto when tacky.

for non-absorbent backgrounds, use neat PVA and plaster while tacky.

SO THAT'S IT FOLKS, as good as it gets, horses mouth, seems like we were all right in some way or another but not quite completely.
 
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RIGHT THEN!

Scoured the net and found a BBA certificate for Unibond plastering PVA, BBA are the people who certify products as suitable for the building trade according to British building regs and here's what they say:

primer coat on absorbent backgrounds of 1:5 which is allowed to dry, followed by a 2nd coat of 1:3, plastered onto when tacky.

for non-absorbent backgrounds, use neat PVA and plaster while tacky.

SO THAT'S IT FOLKS, as good as it gets, horses mouth, seems like we were all right in some way or another but not quite completely.

Looks remarkably similar to what I & several other regulars have already said :confused:

It doesn't cover the need for a strong bonding coat on low absorption backgrounds; vinyl emulsion, gloss, Artex &, god help me :rolleyes: , tiles! which I have also recently covered ! ;)
 
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Can't belive such a simple product can cause so much confusion and misunderstanding.

Thank you for the info trowelmoney1
 
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It doesn't cover the need for a strong bonding coat on low absorption backgrounds; vinyl emulsion, gloss, Artex &, god help me :rolleyes: , tiles! which I have also recently covered ! ;)

Oops, just noticed it does :rolleyes: So more or less confirms it all. I have never used it neat though & in this case, always apply the 1st coat the day before so it dries thoroughly; a second roller coat, allowed to go tacky, just before plastering then keys nicely into the 1st .
 
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I am PVAing at the moment and according to the instructions it should be 5 parts PVA to 1 part water 24 hours before plastering then 3 parts PVA to 1 part water about 1/2 hour before plastering. However, I am plastering with hardwall onto thermalite blocks at the mo.
 
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really!? :confused: thought it would have been the other way around, 5parts water to 1 part PVA and 3parts water to 1 part PVA.
 
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I am PVAing at the moment and according to the instructions it should be 5 parts PVA to 1 part water 24 hours before plastering then 3 parts PVA to 1 part water about 1/2 hour before plastering.
Whose instructions :?: as tmonkey says, I believe you have that the wrong way around my friend! :confused:

However, I am plastering with hardwall onto thermalite blocks at the mo.
Hardwall onto thermalite, you’d do better with a good dousing down with a fine spray hose first & then a 5:1 PVA (that’s 5 water:1 PVA) for good measure. ;)
 
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As Richard has said, think of using water as a first choice. Pva is good at controlling suction and bonding water based products to one another.

It is NOT the answer to all problems, and should not be considered so.

It should be re-named P.F. (plasterers friend).:cool:

Anyway i prefer Alien v's predator.
 
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