My paint is peeling/bubbling and is fluffy!

[Lord83]

Hi

I hope somebody might be able to help me here.

We have recently had our solid brick, external facing bedroom walls internally insulated and plastered, the guys did a great job and the room is now much warmer! After letting the paster dry for about 4 days I painted onto the plaster using several coats of matt paint and it has gone on really well and left good finish.

However in one area were the new plaster meets the old wall (protuding covered up fire place) I am having some problems. The paint just seems to flake off in the corner, slightly on the new wall but mainly on the old wall, and it almost has a weird fluff that is been produced over the paint!

I am thinking of scraping of the effected paint and sanding then applying a coat of damp seal. Then when dry repainting with the matt?

Any help would be much appreciated, want to get it sorted this weekend!

 

[LJW61]

That'll do it, or even a thinned coat of oil-based undercoat will seal it

 

[Lord83]

Great, have put a couple of coats on and has done the trick

 

[Lord83]

Ahh! Looks like I spoke to soon.

I put a couple of layers of damp seal and low and behold after 4days, its bl**dy started to peal again.

Any suggestions?

I am thinking that I should maybe water it down sligthly as it seem to just create a layer that then peels straight off, would this penetrate the area better? Its so frustrating as the patch is only small.

 

[JohnD]

it sounds like efflorescence is coming through. Sealing it was the wrong thing. Scrape it off and let it finish drying. Preferably leave it open for a couple more weeks before applying a thinned coat of matt emulsion. Wait for the drying to finish and the efflorescence to stop before you redecorate. The efflorescence may form on the top of the emulsion instead of pushing it off, so you can brush it away (it is composed of mineral crystals)

there is a possibility that you have damp in that corner e.g. from a bridged DPC or a leak, in which case you will have to fix it.

if there is damp in an old wall round a fireplace, it is usually due to the old chimney being unventilated. Has it got an air brick at the bottom, and an open top to allow airflow?

 

[Lord83]

Hi John D

Thanks for your reply.

The chimey does have an external ventilation brick and also one at the bottom into the bedroom.

The problem does seem to be right in the corner but only on the old wall on chimny, so hopefully the DPC has not bridged, (if it has is this a big problem?). The area effected is not very big 5inches length ways and 2wide.

The old wall does seem dry but, we have had terrible condensation problems here in the past hence the new walls, could this may be a factor? Ie now the room is warmer the wall is drying out, bringing through the effloresessence?

It does seem to be effloressence as it is leaving a deposit of crystals over the paint and the paint as well as peeling. I will scape off all the effected area and dry out then try the watered down matt.

Thanks

 

[JohnD]

assuming it is not a cavity wall, have a look at the outside face behind the damp patch. Perhaps the damp is coming from outside. Even if it is a cavity wall, see where the DPC is in relation to the damp patch.

If it is near ground level, it might be earth piled up, or a path against the wall, or a drip or leak from a gutter, downpipe or drain, possibly splashing up off the ground.

If you can take up the floor in that area, see if it is damp underneath, or well-ventilated. If there is rubble under the floor, take it out.

The area effected is not very big 5inches length ways and 2wide.

This could be a single brick holding water. They vary in absorbency especially in an old house, and some take a long time to dry.

 

[Lord83]

Yea I will have a look at the wall outside the house, and see if there is anything that stands out around the prob area, ie dripping pipes etc.

fortuantly the problem is not ground level it is about 4feet above so it is not coming from a path or moisture from soil comming in. Hopefully it is just effloressence and with a good airing and the correct treatment will be ok.

Will let you know how i get on.

Cheers