Moisture on open beam ceiling
I read some of the other questions and answers concerning moisture or perhaps condensation on the underside of the ridge beam in an open beam ceiling. Some of what others have experienced sounds similar, yet different too.
we just bought the house and could see there was evidence of previous water on the ceiling and end wall (toward exterior). We thought this was coming in from the outside. This room was an addition to the house. is a room about 14 x 18 feet running north to south, so east and west facing roof slopes. The south end abuts the attic of the rest of the house. There is a heating vent high up on the wall. (see image). We have not used the heating some nights but not the cooling at all.
The north wall is to the exterior (see image). there are dark stains down the drywall under the ridge beam on this wall. There are also black marks , dots, on the beam and on the T&G. (see image).
I am not sure exactly how this was constructed, but the actual roof system is 2×10 at 24″ with some insulation, plywood and asphalt shingles. no ridge vent. no eave openings. The T&G and the beams are all solid, authentic.
We are in southern California. For a couple months it has been raining and then dry, then some rain. No rain in last couple of days. We have not seen any moisture. Today is sunny and in the 70ies. At about 3:00 in the afternoon we actually experience dripping from the beam.
What can be causing this, and how to correct it? From the discoloring it has clearly been happening for some time.
Many thanks for any help you can provide. Michael808
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