Mould is inhibited by nitrates. Nitrates are used in foods to prolong the shelf lives of meats and prepared foods. The presence of mould in a wall exlcudes, or elminates risng damp as the root cause, as groundwater, the source of wateer in rising damp, is rich in nitrates as it passes through the soil.
Watch this space!
Mode details are being uploaded regularly, towards the end of every month.