Painters/Decorators HELP PLEASE!

[Dekers]

Background.

Painting walls in Bedroom, they were purple and that way when I moved in, walls are dry lined.  Thought I would start with a coat or two of Dulux Brill White Matt to help obscure the purple as they will be end up an off white Ivory type of colour.

Dulux diluted about 10% with water as so hot, applied first coat on Sat and walls bubbled in parts.  Rubbed down the areas yesterday , bubbles did not burst but went "nearly" flat again, just applied another coat of Dulux and bubbles all back.

Any ideas about the cause and more specifically how to cure, will I need to cut out the areas?  Seems a real pain whatever.

Thanks.

Pics showing a typical area, bubbles are from about 1mm to 8mm in various parts of the wall but in groups similar to this, much of the walls are fine.  They do not flatten when dry.

[TIGHTCHOKE]

Your house is haunted!

[figgy]

Do the bubbles only appear when dry or when wet. 

If when wet roller over them to get rid. If dry then sand them off and repaint.  Try a Matt latex then it should stop any more bubbling as it seals when dry.

Looking again as it looks like a patch of bubbles I think something was spilt or stayed on the wall. The water in the paint has reacted with it causing the gas bubbling. 

Edited July 1, 2019 by figgy

[Dekers]

Just now, figgy said:

Do the bubbles only appear when dry or when wet. 

If when wet roller over them to get rid. If dry then sand them off and repaint.  Try a Matt latex then it should stop any more bubbling as it seals when dry.

They appear as the paint roller goes over the area and stay, even when dry!

They don't go away with more rolling when wet unfortunately.

[figgy]

Wash the walls before painting.

[Dekers]

Just now, figgy said:

Wash the walls before painting.

????

They have 2 fresh coats of Dulux on them, they are clean, will "washing" achieve something over this?

Cheers

[figgy]

No before you paint, oy thing I can think of is sand the bubbles and re coat the area, might take more than one go but should sort it.

I've used a small mini roller to go over problem bits and bubbles in past to break them and leave a smooth finish.

Edited July 1, 2019 by figgy

[harrycatcat1]

I had this problem in a tenanted house and it was candle wax, they had been burning those tea light things.

[Doggone]

The purple paint was not put on properly and it was probably not washable. It just expands and forms bubbles when wetted. Scrape it off. 

Andy

[akka]

We had this exact same thing in our old house. Unfortunately nothing seems to cure it. I never found what causes it, tho it must be a reaction to a previous wall coating of some sort.

We even had the living room walls skimmed over, and some even reappeared through the thin plaster! Our whole downstairs walls were like it.

The only thing I found to reduce them was to wait untill the paint was almost dry, and gently go over the affected area very lightly with the roller and the bubbles would press back down.

Good luck, I feel your pain!

Edited July 1, 2019 by akka
Roller

[vampire]

Had this before on dry lined walls,nothing you have done wrong and only way is to sand and fill.I don't think its from the construction process,its more likely that someone has used cheap paint.

The house I decorated only had this problem in the living room and one wall in particular,again I think its a combination of dry lined and cheap paint not applied properly

[Scully]

Sounds to me like the dry lining is 'honeycombed', which means the walls may need sealing with a sloppy mix of filler prior to painting. It could take a few attempts unfortunately, but the method is to rub in a sloppy mix in circular motions, going over it repeatedly until bubbles stop appearing. 

Another cause could be too thin paint and or a too thick roller, but most rollers create small/tiny bubbles as they roll but these should disappear as you apply lighter pressure to lay off. 

Ensure your roller is totally loaded with paint before you apply it to the wall, and gradually ease off the pressure as you run out of paint. 

[Dekers]

Thanks everyone.

Looks like work ahead for me, it is the paint underneath bubbling, not the paint I am applying, so some digging out and filling seems likely!

[bear-uk]

I've got this problem in a tenanted house that was fully re plastered and its looking like the salt from the old brickwork seeping though the dot dab and plaster and creating solid bubbles like yours and some started going moldy/furry.

Recommendations are take paint off back to plaster and paint with an oil based undercoat to seal it before top coating.     

Edited July 1, 2019 by bear-uk

[silver pigeon69]

I would sand it back to the purple and try an oil based stain block.

[Scully]

25 minutes ago, bear-uk said:

I've got this problem in a tenanted house that was fully re plastered and its looking like the salt from the old brickwork seeping though the dot dab and plaster and creating solid bubbles like yours and some started going moldy/furry.

Recommendations are take paint off back to plaster and paint with an oil based undercoat to seal it before top coating.     

In that case it needs to be sealed with something like Zinsser; if you seal with an oil based undercoat, you will have to use an oil based top coat. 

[silver pigeon69]

3 minutes ago, Scully said:

In that case it needs to be sealed with something like Zinsser; if you seal with an oil based undercoat, you will have to use an oil based top coat. 

I thought if you used Zinsser, you could only cover it with Zinsser?

[Guest]

Try watered down pva glue to seal the wall .it may help 

[Scully]

7 minutes ago, silver pigeon69 said:

I thought if you used Zinsser, you could only cover it with Zinsser?

No, Zinsser is shellac based and can be over painted with either waterbased or oil based paints. The only drawback with shellac based products is that they dry extremely quickly, so it is easy to leave brush marks or create drag marks, which is why those who use it on large areas tend to spray it on. Brushes have to be washed in meths. 

[Paddy Galore!]

the underlying layers of paint are usually very thick when this happens, when you put a fresh coat on it's putting moisture into the existing paint, where the existing paint hasn't adhered to the wall surface properly it causes a blister, this usually happens with eggshell or silk finishes. this will carry on happening to the affected area. I've treated walls with oil based undercoat before and it's helped as it forms a barrier stopping moisture ingress through the paint layers, you need to let the wall dry out completely, pop and scrape back the blisters, re treat the pock marks with the oil based paint, then fill and rub down, then oil based undercoat, then final emulsion, you don't need the red Zinsser, it stinks to high heaven and is very expensive, if you or any of the household have breathing problems then don't go near the stuff, you could try the yellow Zinsser, it's oil based and is a bit easier on the lungs, contrary to what's been mentioned earlier you can put emulsion over undercoat, it's an old trick of the trade for covering and sealing stains.

atb

paddy

[PPP]

Woodchip wallpaper ... job jobbed

[Jaymo]

10 minutes ago, PPP said:

Woodchip wallpaper ... job jobbed

And some pampas grass out the front 🙂

[hodge911]

Could be if the purple was put on new plaster they painted it watered down PVA.

I did and when I went to repaint a couple of years later the same thing happened but worse .

I ended up peeling it off by hand and priming it with watered down emulsion and building up coats slowly

[Scully]

1 hour ago, Paddy Galore! said:

the underlying layers of paint are usually very thick when this happens, when you put a fresh coat on it's putting moisture into the existing paint, where the existing paint hasn't adhered to the wall surface properly it causes a blister, this usually happens with eggshell or silk finishes. this will carry on happening to the affected area. I've treated walls with oil based undercoat before and it's helped as it forms a barrier stopping moisture ingress through the paint layers, you need to let the wall dry out completely, pop and scrape back the blisters, re treat the pock marks with the oil based paint, then fill and rub down, then oil based undercoat, then final emulsion, you don't need the red Zinsser, it stinks to high heaven and is very expensive, if you or any of the household have breathing problems then don't go near the stuff, you could try the yellow Zinsser, it's oil based and is a bit easier on the lungs, contrary to what's been mentioned earlier you can put emulsion over undercoat, it's an old trick of the trade for covering and sealing stains.

atb

paddy

I agree oil based paints are good for killing stains, but not as good as Zinsser, which also comes in white incidentally,  but I wouldn’t advise painting an entire wall with oil based paint if it is to be topped with a water based emulsion. It will stick, for a while, but eventually cracks will begin to show in the emulsion as the underlying oil paint underneath dries much slower, similar to the craquelure effect you see on old oil paintings. I don’t understand how it’s possible to put moisture back into an existing paint layer once it has dried? 

[Doggone]

Lick your finger and put it on the wall, you’ll soon see if the emulsion is waterproof or not

Andy