Evening all

Local hardware shop recommended using 4 to 1 mix of water and PVA to seal the newly plastered walls of our web en-suite. All well and good but the mix is quite runny and in replastering the walls, the plasterer has gone over the ceiling a bit. Only a few cm, but enough to need sealing and painting.

How the hell do I seal that but without dripping stuff all over everything? Thicker mix of PVA and water? Just water the emulsion down a bit? Something else?

Dust sheets. It’s never going to be a tidy operation.

I’ve only ever used cheap emulsion. Never even bothered watering it down to be honest.

This newer plaster ‘recipes’ are more forgiving in this respect and sealing isn’t so vital.

Happy to be corrected.

I have only ever used slightly thined emulsion. My plasterer friend said something about PVA being rubbish? Anyway, all seems good in our house many years later!

1/2 and 1/2 emulsion and water is what our chap said..
paint master in whalley bridge is really good if your needing to buy stuff btw

We are in the midst of renovating our house and I have painted a lot of bare plaster. No need to seal with anything else

I have found that using a good vinyl emulsion watered down 20-30% is great for the first coat. If you mix well shouldn’t drip too badly. The first room I did I put the paint straight on not watered down but because a lot soaked into the plaster the net effect was that I just used more paint, and good paint is pretty expensive.

Do what the plasterer recommended. You did ask him didn’t you? 😉

PVA is crap. If you re wet it after it dries is becomes wet again. New plaster should only need a watered down coat of emulsion – I used MacPhersons high coverage trade emulsion watered down by 40% as that is what the tin says. Standard DIY emulsion doesn’t have as much pigment in it (and frankly is crap) so you don’t water it down as much,maybe 10%.

Anything but pva

If you don’t water down the paint to start off with the first coat has all the water sucked out of it by the plaster – new plaster is very thirsty!

This can result in the paint peeling off later on. Do it properly!

Iv’e never used pva, many sources of info say that you shouldn’t do it so ive always used thinned emulsion. Its a pointless step that can cause problems so why bother.

If you really want to seal bare plaster then Zinsser Gardz (very good but overkill in your situation) or Beeline primer sealer is better.
The reason given for avoiding pva is that its reversible, which means it never sets completely, which means damp conditions will make it sticky again.

TLDR : Just thin the emulsion first coat

Spray it on with a cheap sprayer bottle.
Need to do our new bathroom soon, spray bottle already on standby.

Used this as I couldn’t be bothered to water down cheap emulsion. Did the job well and a year later no flaking paint.

http://www.screwfix.com/p/no-nonsense-trade-bare-plaster-paint-brilliant-white-10ltr/51004

we just used some cheap pva? based sealer from wickes was 3 quid for a bottle, wuite thin but paint went on fine afterwards

Cheap contract emulsions like the above screwfix product have caused me more problems than i care to mention.

Not picking fights here but 30+ years of experience have made me hate them , especially in bathrooms and en-suites.

For example, with Dulux Supermatt which is a more expensive version you can almost cover bare plaster in one coat with a good roller, which is what many disreputable contract painters do. A few years down the line subsequent coatings will gleefully come away from the wall in sheets, especially if you’ve wallpapered over them.

Bigh – I’ve always thought that – use the proper trade emulsion watered down (it’s designed to be watered down) and it’ll be perfect.

Don’t use PVA.
You don’t need to ‘seal’ it. A mist coat (thinned emulsion) allows to paint to soak in and be less likely to flake later (e.g. when removing masking tape).

Use a flat matt emulsion for the mist coat (not vinyl matt)

[video]https://www.youtube.com/watch?v=VTuaH-6rGRw[/video]

I’ve used watered down, cheap matt emulsion recently. Where I’ve not watered down enough, it’s flaked off in parts when ‘proper’ coats applied. 30% water’s about right.

I used high coverage Macphersons trade white emulsion watered down 40% as per the instructions to paint this wall. Only 1 coat on this wall.

Wait until the plaster is PROPERLY dry first too, be patient and don’t take shortcuts with heat or dehumidifiers.

As others have said mist coat of watered down emulsion Not PVA. PVA is used before skimming plaster

use a paint roller to apply it, it is quicker and less messy than a brush.

my room lounge looked idenitcal (bar mirror image) to newrobdob’s a week ago! My plasterer when asked by me said dehumidifier is fine, so its been in there runnning away sucking 6-9 Litres out the room each day. All painted now, coving put up, hearth laid, sickets back on and … and… curtain poles and stove to go back tomorrow and I think I am ready for Christmas. well…sort of…not!

BOLLOCKS

Already done the wall with PVA. ****socks

the value white bucket from B&Q mixed 50/50 paint to water is spot on . once you’ve done the mist coat do a coat of straight white paint. jobsagoodun.

always use white because even if you are putting a colour over the top the light reflects better through the colour

I used dulux trade supermatt watered down. 2 mist coats followed by 2 full coats. The paint looks great, very matt and deep. Was £60(2 big tubs) to paint a 2.5m by 5m room with quite a bit left over. Oh and its the heaviest thing in the world so get a trolley in bandq..

Leyland Trade emulsion
Water it down 1 part water to 2-3 parts paint for the first layer on fresh plaster.

I think a dehumidifier is a good idea too though, helpful for getting moisture out of the plaster before the first coat and between coats, especially in cold weather.

Remember, Leyland Trade emulsion 🙂

as mentioned several times above, do NOT ever PVA a wall, especially if you want to tile it. It’s terrible advice that keeps getting trotted out by poor tradesmen, PVA is water soluble and will only help the tiles fall off later.

As a tiler I love it when someone has PVA’d a wall before tiling, helps me take them off very easily.

Good old Internet!

As a ( thank God) ex plasterer, I tell customers to use cheap emulsion. Never bitten me in 32 years.

Next question then – what the **** do I do with the wall already coated in PVA?!

I’ve just had two rooms plastered and the chap who did it said not to bother with a watered down coat as newer stuff is much better.

Also left it to dry properly for a week before painting.

Leyland trade Matt emulsion is amazing stuff too.

just going through the same thing with re-plastered rooms – the plasterer said 50/50 mix so am using a B&Q bucket of white emulsion well watered down

All the pros I use on site always mist coat. As for the pva, mmm

renton – Member

I’ve just had two rooms plastered and the chap who did it said not to bother with a watered down coat as newer stuff is much better.

Saves on posh paint if you batter it with B and Q cheap stuff first.

Ooh I’ve just done a load of this, used some good quality trade emulsion watered down 50%. It works. Most of the advice I’ve read is saying don’t use PVA, if it’s a plastered bathroom and is going to be tiled then you should use some sealant, we used some SBR which seems to be the main ingredient in the proprietary plaster sealants.

You could seal it with SBR, which basically does the same thing as PVA but doesn’t rewet afterwards. It’s generally what tilers use.

I was advised to use it before tiling, don’t ever use PVA before tiling!!!

Not tiling thank goodness, will be using a proper bathroom paint. really ****** off with the local hardware shop now though

Don’t be pissed off with the hardware store, they are supposed to sell hardware, not provide DIY advice.

Next question then – what the **** do I do with the wall already coated in PVA?!

You could try painting a bit of the PVA’d wall, it might be fine. If you really want to be sure of a good job over the PVA then you rub down the wall, sugarsoap it, leave it to dry, and then use an oil based primer sealer (e.g. Shellac) as the first coat.

Screwfix trade bare plaster emulsion works well and no need to thin! NEVER use PVA!

I used PVA once. Wasn’t very good. Wall paper paste works.

Why on earth would you put wallpaper paste on? Completely unnecessary.

It worked. And it made painting a doddle. Recommended by a long term plasterer.

As I experienced the plaster sucks all the moisture up, this then doesn’t happen on your paint and the first coat goes on so well.

I did watered down paint before, harder to apply than diluted paste.

You then don’t waste your paint?