When walls haven't had a mist coat of paint

moneyistooshorttomention

When I bought this house - I had workmen go through it replastering and then repainting throughout.

Paint has been flaking off part of the bathroom walls subsequently and, from my reading of this forum, I think the probable cause is no mist coat of paint was done on top of the plaster before doing the standard painting as per normal.

I think I've probably not got a mist coat of paint on any of the walls of this house in between the plaster and the "normal paint":(:mad:.

In the course of having my kitchen refitted - it's obviously going to be re-painted and the previous coats of paint flake all too easily off the walls if knocked and hence I suspect there is no mist coat there either and there should be.

What is the best way to deal with things now in the course of redecorating these rooms (ie right now - that means doing the kitchen and bathroom again:().

1. Am I right in thinking this is probably the cause of the paint problems?

2. Obviously - I'm going to have the walls sanded very thoroughly before they are re-painted. Should I get the decorator to do a mist coat of paint now (ie on top of the residue of previous paint on the walls that remains after this thorough sanding has been done)? Followed by then painting the walls in the normal way (ie with 2 coats of paint as per standard).

I'm basically wondering how to get these walls "normal" - so that paint can be applied in the normal way now and from here on in after and will be as hard-wearing as normal.

GDB2222

We had this problem and solved it by reskimming the affected walls. In a bathroom only.

Lining paper might also solve it.

Furts

A problem I have come across is well meaning DIY folks coating the bare plaster with vinyl silk, or vinyl matt or similar. This seals the plaster, it does not dry out properly, does not easily take filler and it pushes the paint off.

Obliterating emulsion should have been used. This will coat, fill, be capable of sanding, and take filler. All round a very good product. But it does not take marks and dirt.

What happened on your walls?

moneyistooshorttomention

Furts wrote: »

A problem I have come across is well meaning DIY folks coating the bare plaster with vinyl silk, or vinyl matt or similar. This seals the plaster, it does not dry out properly, does not easily take filler and it pushes the paint off.

Obliterating emulsion should have been used. This will coat, fill, be capable of sanding, and take filler. All round a very good product. But it does not take marks and dirt.

What happened on your walls?

I was being a bit too trusting basically - and not knowing whats what.

So - the walls throughout the house were all replastered (complete with fake ceilings being put throughout the house and plastered - courtesy of having "stuff" on the original ceilings and cornicing stuff had been removed from around the edges everywhere by my workmen).

Then I was told by them "That's it - the plaster is dry now. So we will do the painting next". They did the painting. Since that time I've been reading various things on t'Internet generally/here about "mist coats" of paint being put on new plaster before the painting is done.

I have a 99% suspicion they never did a mist coat of paint on any of the walls/ceilings before putting on paint in the normal fashion - ie the standard 2 coats.

The walls/ceilings in the house as a whole were done with standard Dulux matt paint. The walls/ceilings in kitchen and bathroom were done with the bathroom version of Dulux paint - think it was silk???

So I think I'm pretty clear on what should have happened - and it didnt. I need to know what is best to do now to put things right.

a. As regards the kitchen and bathroom - with the type of paint used in kitchens/bathrooms on the walls.

b. The other rooms in the house - with standard matt paint on them.

Hence - I'm wondering whether the best thing to do is to have the walls sanded very firmly in the kitchen and bathroom (which are being re-done now), followed by the standard 2 coats of paint on top of the remains of the original paint. BUT - with that missing "mist coat" of paint done in between the "sand like mad" stage and the "painting as normal" stage?

I don't want to think of plastering (as I've had the plastering done - and don't want to go there/pay for that again). I want plain standard painted modern walls - and am wondering now whether it's possible to put up lining paper first and then paint as normal in the other rooms (when I eventually decide to paint them again anyway - in a few years time). I don't wish to use lining paper on kitchen or bathroom walls.

SO (for kitchen and bathroom) I am wondering whether best plan of action is:
1. Sand like mad.
2. Do that missing mist coat of paint next.
3. Then paint them as per normal - ie Dulux kitchen/bathroom paint.

FreeBear

GDB2222 wrote: »

We had this problem and solved it by reskimming the affected walls. In a bathroom only.

If the skim plaster goes over an unstable substrate such as flaking paint, it will probably chip & flake off over time. You may well get away with it for a few years, but if tiles are then stuck on, the plaster will fail.

moneyistooshorttomention wrote: »

SO (for kitchen and bathroom) I am wondering whether best plan of action is:
1. Sand like mad.
2. Do that missing mist coat of paint next.
3. Then paint them as per normal - ie Dulux kitchen/bathroom paint.

Sand like mad - Get yourself a cheap orbital sander like this one- http://www.screwfix.com/p/energer-enb623sdr-sheet-sander-230-240v/3348g
Use a decent P3 rated dust mask and some disposable overalls. Make sure the door is sealed and the windows open - Sanding will produce loads of dust which will go everywhere.

The mist coat is primarily to seal the surface of the plaster - Sanding will roughen up the surface and provide a key for paint to stick. I'll leave others to comment on the merits of a mist coat or primer.

TRB

If the plaster work has not had a mist coat sanding will not help as any paint that is left will not be adheard to the plaster. I have found in the past if a mist coat has not been used you can get a scraper behind the paint and it will come off very easilly.

mchale

Paint any walls you can with wallpaper paste/pva.

Grenage

mchale wrote: »

Paint any walls you can with wallpaper paste/pva.

Christ, No!

Use a scraper to go over the walls and remove the bulk of the loose paint, then sand.

At my last place, I had to sand every wall of every room. I connected the exhaust of an orbital sander to a Wickes wet and dry vac; you still need a mask, but it stops the room being filled with dust.

I would mist coat and proceed as normal once done.

Davesnave

mchale wrote: »

Paint any walls you can with wallpaper paste/pva.

I wouldn't . PVA and bare plaster really aren't great bedfellows.

I think you could well be OK in all the rooms where a matt finish was used.

I've only watered my matt paint down by about 10- 15% for the mist coat and there have been no problems here with peeling or flaking.

In the kitchen & bathroom, someone will probably have to get the walls back to plaster, or if that's not entirely possible, then there should be sufficient sound surface to paper over.

Sounds like you hired the Chuckle Brothers. Emulsion painting is not skilled work, so save some money and do it yourself in future.

minibbb

Zinsser do a product called peel stop- may be worth a look although ive not used it.


If you need to sand walls I cannot recommend this product enough. The hose fits into a henry hoover or similar and it gobbles up virtually all of the dust. Prior to buying this I sander one room normally and it was horrendous!! The abranet sheets are far superior to normal sandpaper too. Buy 10 or so 120 sheets extra.
http://www.decoratingdirect.co.uk/viewprod/m/MIRKA_HANDY_ABRANET_DUST_EXTRACTION_STARTER_KIT_80_X_230_MM/