This is a very complex problem, much depends on the type of building, old, new, in-between, single wall or cavity wall, with a cellar, etc etc. Should you make the wrong decision and spray or coat a wall, it could make the matter worse by preventing a building from "breathing". This site might be of help MyBuilder.com [info@mybuilder.com] unless someone on this Forum has the same type of building as yours and can recommend a company. Good luck.
Jennifer Selig ● 2125d