I'm planning to paint the perimeter wall of my house, which is unfinished grey render at the moment. As it will need one or two undercoats, I wondered if interior emulsion would do, as I've got about 15 litres of this I dont need. I'm then planning to finish with Johnstones exterior masonry paint. Would cheapo interior paint do as an undercoat to seal the render? I've also got about 3 litres of water seal I could add to the paint to help it seal the render. Shame just to throw this unsused stuff out.
Cheers
James