Originally Posted By: rkuntz This post was automatically imported from our archived forum.
I would like opinions on the following condition: Dark coloration on the ceiling of a ranch house directly below the attic rafters. The coloration was faint but noticeable. Ceiling and walls are plaster. Attic had gable vents but no ridge vent and limited sofit vents. House also had water entry problems in the basement.
Originally Posted By: rmeyers This post was automatically imported from our archived forum.
Ron,
If the dark areas follow the joist spacing and tend to fade out as they move to the interior there is probably batt type insulation in the attic. The insulation may have been installed after the ceiling was applied and it does not lay down into the corners tight next to the ceiling joist. This allows cold air from the soffit vents to work along the joist. The cold transfer along the joist is causing just enough surface condensation to collect dust or in severe humidity conditions to cause mildew as suggested earlier.
Originally Posted By: rmeyers This post was automatically imported from our archived forum.
Ron,
If you get this before you go to the site, check under any blown insulation for old batts. What was the age of the house? Was it always electric baseboard heat? Let us know the results of tomorrows visit. Thanks!
Still looking for clues!  Good luck! 
Originally Posted By: rkuntz This post was automatically imported from our archived forum.
Thanks Russ
The house is about 30 years old. The attic is insulated with 6 inches of fiberglass batts. Sofit and fascia is wood with small round sofit vents. The attic does have two gable vents.
. But I would also include a check of the heating system.