Hi - Recently I've noticed random damp patches on my 3 year old K render below a window and near frontdoor entrance. The damp markings seem to be worse when bad weather hits. When the weather is nicer the staining is still present I believe - less so maybe as the aspect is south facing so may dry out. At first I thought it might be a burst water main from the outside taps, but that theory was soon scrapped when I isolted the taps. Plus you would expect to see the staining constantly to the same degree or progressively getting worse which you don't. Any ideas what it could be? There is a DPC insatalled - also approx 3 years old so shouldn't be rising damp?