Sorry another plastering thread, PVA or emulsion

shopaholicjules

Hi
Sorry about this being another question about plastering but ever since they updated the site, i struggle finding past threads on the forums. It comes up with other things but not necessarily about plastering, so apologies.

I am in the process of havng most of my new house plastered. A couple of rooms are now dried out.
From what I can remember there seems to be differing opinions about PVA ing the walls and some people saying watered down emulsion.
Can anyone give me there opinion on what I should do and the pro's and con's of both.
I need to start getting on with it this week as I move in in a couple of weeks.

Thanks
Jules

amarg

Not sure if you mean before or after plastering?

If you mean before plastering then PVA is what you require,or wickes bonding agent. More info on this here- http://www.ultimatehandyman.co.uk/forum1/pva-vs-wickes-bonding-agent-t3447.html

After the room has been plastered do not use pva under any circumstances, see here- http://www.ultimatehandyman.co.uk/when_to_paint_new_plaster.htm

I hope this helps!

nickj_2

pva befor painting water based paints it a big no no .
use thinned cheap emu for the job

shopaholicjules

Thanks for your advice.
The walls were PVA'd before plastering.
The question (soory it wasn't clear) was about after plastering has been done.
Why is it that lot's of plasterers says use PVA when some people say it's a big no no.

If I buy cheap emulsion, do I need to water it down, I remember reading something like this and if so, by how much.

Thanks again
Jules

jason_s_2

Like nick said DON'T pva the walls first,use watered down emulsion,use the cheapo BnQ matt its about £8 i think, dilute this by about 20% and give it 2 coats.Then stick your top coat on.If you don't dilute it the paint doesn't absorb in the plaster and just sits on top and after awhile peels off like paper.I'm sure missy G will put me right if im wrong lol.

nickj_2

yes add water, you need it thin enough to soak into the plaster , around 1lt of water to 5lt of emu

use matt emu ,

diamond_dave

Hi All, I've always found it better to use a proprietry plaster sealer before painting the walls with emulsion. As said previously, the paint will eventually build up and lift from the walls. I've just spent a whole day stripping a wall of paint before I could even paper it! The plaster sealer is only about 7-8 quid and goes a long way. Remember good preparation is worth the effort in the end.

shopaholicjules

Thanks all for your advice
I will buy my matt paint, water it down and get on with doing the rooms that have been plastered so far.
I'm glad I posted my question as my plasterer ( I think his workmanship is excellent, not the fastest but very reasonably priced) said to use PVA but I am going to ignore his advice from what people have said.
If I didn't use this site, I would have gone along with what he told me as he has been a plasterer for over 20 years and is now also a teacher of plastering, building etc to year 11 students.
Thanks again

misgrace

Hi Jules, yes Jason is correct, but here is a link to another 'new plaster question' which might be of help to you.

http://forums.moneysavingexpert.com/showthread.html?t=548508

I dont know why some plasterers suggest PVAing a wall prior to painting,( Jason wouldnt) as it is the wrong thing to do.

You can apply PVA to painted walls for example.... if you have done a load of filler, or spot plastering on an existing painted wall, and you want to hang paper.
If you apply diluted PVA over the bits you have filled/spot plastered, after you have sanded, this will stop the filler crumbling when you hang the paper.
The paste can react, when it hits the bare filler, and if your lucky it will react straight away, or within a few hours, but sometimes after you have papered the whole room, and a couple days down the line, the filler will crumble, and there will be horrible lumps and bumps, and your butt joins will open up, then you would have to remove the whole lot.:eek:

The other time you can apply diluted PVA again only to existing painted walls, is when you remove the old paper, and you get a load of flakey paint left behind.
You can sand it back, but the next day it will flake up again, and I'm sure this has happened to lots of OP.
If you apply the diluted PVA after you have rubbed down the flakey bits, this will stop it from flaking up again, and make it easier for you to fill the edges of the old paint.:D

Also, when you apply your miscoat, in the evening turn on your lights, in the artificial you will see any slight nicks, trowel marks that you wont see in the actual daylight, (if there is any), read the link above and follow my instructions)
Also, if the new plaster is too smooth, then you might have to give it a light rub down to make it easier for the paint to adhere to, and its best you lightly sand it anyway to get rid of any nibs or snots, causes by dust particales as its drying out, and also give it a light rub down between coats.

Happy painting.:D

HugoSP

I have recently plastered out my whole kitchen and utility room.

I went and raided the garage to find a number of tubs of either full or partly used cheap white emulsion, we watered them down some 10 to 20% and used that for the first coat only. I even got 2.5 litres from a lady via Freecycle!

Then we used new emulsion all of one type/manufacturer to do the remaining coats, with the exception of one wall that is a different colour.