I just got back from our HOA meeting and the president stated the retaining walls in our complex may need replacement. The landscape contractor said the efflorescence appearing in the concrete walls holding back the slope behind our complex would eventually weaken them and cause them to fail. The slopes are substantial and are only 10 feet away from the houses so it is cause for alarm if this is the case. However, the walls have stood for 19 years and there is no sign of damage or mortar crumbling in any of them. The walls are concrete block--not a solid wall, but I don't know if concrete or dirt was packed inside it. The estimate for each wall was $15K and we'd have to do 5 of them. Is the efflorescence actually weakening the wall?
Thanks, Paul