Martyn Goodram
Hi Sue, First check outside for any damage that could be allowing water in,such as mortar gaps or cracked render.If this is not the case then rising damp could be the problem, usually leaves a wavy pattern on the wall up to 1m high before gravity sets in.The moisture travels through the capillaries in the brickwork (capillary attraction) like a sponge would soak up a liquid. This moister will bring with it salts and nitrates from the ground that will eventually break down the plaster. The solution is to remove the infected skirts and plaster and install a waterproof membrane before re-plastering. If a membrane is not installed,the fresh plaster will re-activate the salts and nitrates that are still in the brickwork and also allow them to migrate. With this procedure a chemical injection DPC is not necessary but recommended on other walls before damage is caused. Before having any work done,get a survey done to determine that this is the fact, as humidity could be the cause. Hope this helps Regards Martyn
