Browse Forums Paving & Concreting Hi, I have an area of zincalume cladding encasing a number of external downpipes. Unfortunately one of them has been permanently stained by some diluted phosphoric acid -… 0 906 To my understanding early saw cuts are to control shrinkage cracks, so doing them now would be pointless. Control joints may reduce ugly cracking during periods of soil… 3 9857 |