[lord flynn]

Hi
We are wanting to get our harled cottage painted but it seems as though normal paints are out for this, and that we should use breathable paints only? can anyone verify this please?

[Zebedee]

Lime wash.

http://www.scotlime.org/en/faqs/

[lord flynn]

thanks zebedee-it gets more complicated since I posted. the house was (poorly) painted before we bought it and its highly doubtful that breathable paint/limewash was used (certainly doesnt look like limewash). We've had some harling replaced so now have patches of unpainted harling. my understanding is that limewash etc wont cover existing paint?

[Zebedee]

If it's some horrible, so-called weatherproof paint you've got on there, try and scrape it off first. Or just live with it for a while longer and let it weather away. I tried jetting some paint off my old natural stone walls (Dorset) but ended up pitting the soft sandstone. Also watch your step with 'Breathable'. The term is bandied about almost to the point of meaninglessness. Find a simple, natural lime wash and stick with that. 

I'm guessing, but there must be tons of lime wash paint suppliers in Scotland you could choose from given the prevalence of natural building materials.

[Buttermilk]

When we did our annual lime rendering inside the cattle buildings, inclucing the parlour, we bought sacks of hydrated lime from a builders merchant.  Mixed with water and put on with a yard brush.  You had to be careful not to breath the powder and to wear long sleeves and gloves to avoid skin contact.

[oor wullie]

Harling is done with cement (at least in modern buildings) so is there any advantage to using lime or something breathable?  (It is understandable using it for painting stone walls that have lime mortar but that's different from a harled wall).

I just used exterior masonry paint.

Having written that I see that the sandtex paint I used is actually breathable.