It's a micro porous finish, allows structures to breathe, don't know much else about it, other than it's around £75 or so for a 20ltr tub. https://www.rawlinspaints.com/home/...ilate-pro-insulating-s-flex-coating.html#full For that price I prefer to use Sandtex smooth or fine texture masonry paint, available in more colours, it's still a micro porous finish. http://www.sandtex.co.uk/products/sandtex-fine-textured-masonry-paint/ There also Trade Sandtex High Cover Smooth Masonry paint. http://www.sandtextrade.co.uk/product/sandtex-trade-high-cover-smooth-masonry/