Painting concrete blocks - which paint?

[AlanUK]

My new garage is built from brick and block, and I want to paint the inside blocks.  Which paint should I use?  And is an undercoat needed?

[Mr Punter]

I have used masonry paint.  No undercoat but watered down first coat. You could just use emulsion if you want.

[Ferdinand]

Suggest a long pile roller, or perhaps spray if you can.

[PeterW]

Wilko Silk emulsion paint, long pile roller and he first coat at 20% added water. Will need 3 coats but will be fine for years ..!

[AlanUK]

Thanks all, that should do it.

[scottishjohn]

success with emulsion will depend how rough and porous the blocks are- and how good a finish you want 

its not the right thing --but may work if blocks are very smooth -masonry paint is the right stuff 

 I would certainly leave it a week after first coat before applying next one

 

Edited August 25, 2020 by scottishjohn

[AlanUK]

Thanks John.  Would you concur with Mr Punter above about watering down the first coat too?

2 hours ago, scottishjohn said:

success with emulsion will depend how rough and porous the blocks are- and how good a finish you want 

its not the right thing --but may work if blocks are very smooth -masonry paint is the right stuff 

 I would certainly leave it a week after first coat before applying next one

 

 

[scottishjohn]

8 hours ago, AlanUK said:

Thanks John.  Would you concur with Mr Punter above about watering down the first coat too?

 

y es.

my garage was steel frame and blocks --very rough finish ,so were suggested and used a special 2 part  under coat which sealed it all and filled in surface  holes --then one coat of gloss paint --still shines now 30+ years later .

years later I split in to  3 units and just used silk emulsion I was suprised again how it just sucked it up - but seems to be as good a finished job --just not as cleanable like true gloss paint ,but would be fine probably for a domestic garage.

a modern masonry paint will be better to clean, I think 

but will cost more

 

used an airless industrial sprayer -used much more than I calculated due to blocks sucking it up ..540sqm  !!