Exterior Paint Blistering

parishsavings

Hi, my exterior paint is blistering and bubbling in places.
I am guessing this is either damp or oil based paint reacting with the plaster.

I understand there is something available that can be painted onto the plaster first to seal it against reacting with the paint??

One of the problems I have is that where the paint has blistered there is no longer a smooth skin on the plaster, instead it has exposed a grainy surface underneath, trying to upload a photo to show what I mean!

parishsavings

Pic attached

martinr5232

parishsavings wrote:

Hi, my exterior paint is blistering and bubbling in places. I am guessing this is either damp or oil based paint reacting with the plaster.

Had that with my house when it drys out it will start peeling.
I ended up powerwashing the whole thing then painting it with stabalising primer finally two coats of good quality emulsion.

That was seven years ago its still as good as the day i done it.

dodzy

parishsavings wrote: »

Pic attached

Can’t see any blistering in that pic, only where you removed previous coating back to the surface, and where you didn’t. As above post suggests, always use this or similar when repainting old surfaces. I find the truguard excellent.

http://www.leylandtrade.com/products/product-detail/truguard-stabilising-masonry-primer.aspx

martinr5232

Thats the stuff i used it works well not one bit of flaking.
True saying if a jobs worth doing its worth doing right.

parishsavings

Great stuff, thanks for the advice. The photo shows a patch were a bloster had formed and when i removed it this was what i was left with.

Will the primer seal it all up / create a skin for me?!

dodzy

parishsavings wrote: »

Great stuff, thanks for the advice. The photo shows a patch were a bloster had formed and when i removed it this was what i was left with.

Will the primer seal it all up / create a skin for me?!

Yes

parishsavings

Brillant. Thanks a million for all the advice.

coxy123

Apologies for re-starting an old thread - I can't see any attached picture but I think I may have similar issue to OP in that paint at plinth at front of house is blistering - see pic. Recommendation to use trugard as mentioned? Thinking of repainting exterior of house this Spring when weather picks up and I get the time to do it :) . Thanks

20220128_084050[1].jpg

Deregos.

https://www.boards.ie/discussion/comment/118630788#Comment_118630788

Good scape down & powerhose, then neutralise any efflorescence affected areas with diluted vinegar for a day or two, powerhose again, let dry and paint a couple of coats of something like this on before painting with exterior emulsion.

https://www.duluxtradepaintexpert.co.uk/en/products/dulux-trade-alkali-resisting-primer