I've posted onto the builder's section, but then I thought you may be able to help. Do I need to apply a waterproofer before applying Dulux Weathershield or is it waterproof enough? Got a job with porous solid walls and penetrating damp. Can anyody reccommend a product that works?
B&L, Choose one or the other. If you do not want to change the appearance of these walls then use a masonry waterproofer (two coats). Should you wish to brighten up these surfaces then use the Weathershield masonry paint system (old render may require a coat of stabilising solution first).
A good masonry paint will be fine for penetrating damp [not rising damp]and will act as a barrier against normal wet weather but just make sure there are no defects in the masonry such as cracks or bad pointing.