Painting directly on to a concrete garage...

[jamiednm]

We have a garage in the back garden which we want to neaten up. We have recently had the door, roof and gutters replaced so the last part of the refurb is the walls.

It currently looks unfinished - there is no rendering or cladding to it at all. We plan to move house in a couple of years so I don't want to spend a fortune on it.

Can masonry paint (or another kind of paint) be applied directly or do I need to fix some kind of 'outdoor plasterboard' first?

Also, is rendering an expensive alternative?

Thanks

 

[JohnD]

masonry paint is fine.

precast concrete is very "hungry" (absorbent) so it is essential to apply one, or preferably two, mist coats of the paint thinned with water, so it soaks into the "pores" and seals them. Otherwise the solids of the paint tend to lie on the surface without soaking in. I like to use 20% water though some people use less.

the mist coats must be applied by brush, and you will find they immediately disappear as they are sucked into the concrete. You will know you have killed the suction when this no longer happens, then you can apply the paint straight from the tub.

stir it very very well before and during use.

 

[Bosswhite]

if the surface is porous or chalky I would use a coat of stablising Solution, then a couple of coats of Masonry paint of your choice.

 

[dhutch]

When we painted the concrete blocks of our garage (admittedly, twin skin) we just use normal matt white emulsion, single coat, applied with a brush, no a mist coat.

Did half of it on cheepy own brand and the second half in Dulux. The later was impressively more white that then own brand and not more much expensive. No issues with either 10 years on. Makes it much brighter inside.


Daniel