There is a large damp patch above the skirting board of an interior (load bearing) wall. It doesn't feel wet but has stained the emulsion painted surface.
Could this be due to blocked exterior ventilation vents, or could it be rising damp - assuming such a thing exists ?
Do you have a dog...or a toddler...:)
When you say interior wall....do you actually mean an exterior wall ie this wall is between you and the outside of the house? If so, check the level of the driveway / path outside - has it allowed run-off to seep into the walll?
Also, every house has a cold spot - could this just be your coldest therefore dampest part of the house?
Has the emulsion started to blister off?
The wall is totally interior, between the lounge and hall.
There are no pets or toddlers and the house has full central heating and I can't detect any cold spots. Emulsion, over lining paper, (3 months old) has not started peeling.
Check on exactly what is in the lounge and the hall that might have caused it. The cause might not be there all the time, depending on what people are doing in both rooms. Also check on the room directly above the wall. Is something dripping down from upstairs?
Random patches are often the most difficult to diagnose, Derek. A sem-circular patch right on the skirting board usually suggests rising damp. There is such a thing, although not as common as people think.
Before trying anything drastic, it might be worth sealing the stain with a stain blocker, and painting over it. Then just keep an eye on it to see if it returns.