On Wednesday, September 27, 2017 at 5:12:11 PM UTC+1, Mark wrote:
Harold Davis writes:
Hello,

I need to paint the concrete window sills and the window surrounds on my
roughcast kit bungalow near the Atlantic coast of the Isle of Lewis in
Scotland. They're painted at the moment but haven't been maintained for
some

Third question... The walls are roughcast and look mostly okay for the
time
being although in places they are weather-stained and I plan to paint
them. I
was thinking one coat of SBR followed by two coats of masonry paint. Does
that
sound okay? Or would it amount to putting a vapour barrier on the cold
side of
insulation and thereby muck up the ventilation something rotten? I'd like
to
use paint that doesn't need to be recoated in the next 20-30 years.



I use a Stabilising Solution which is not PVA or SBR on masonry
https://www.toolstation.com/shop/Pai...olution/p75668

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I'd soak the sills with a 2 part product which cures whatever the conditions. Fibreglass resin, Rustins Plastic Coating etc. Then skim with a 2 part filler (e.g. Profil from Toolstation). Then paint with anything you fancy, which should last forever because it will be on a non porous surface. IME no surface coating can cope with crumbly sills.