Replies

1. 
   Guest_ | Sep 04, 2000 04:09pm | #1

   *
   Sounds as if your friend has moisture-laden air inside the house that's escaping through the walls, but is slowed considerably by the studs (which is after all the densest point in the wall structure).

   I suspect it comes from very moist air from the second floor baths (and perhaps a laundry ?)

   Maybe just running the bath exhaust fans a bit longer would help; maybe the fans need to be larger; maybe the fan vents are blocked ? (Little birds have an interesting way of edging into exposed vents and blocking them with nesting material).

   Anyway, before opening up the walls, I would investigate the source of the moisture and try to relieve that problem. If he finds that much moisture on the wall studs, I'd bet he has considerable condensation on his windows, too. Check it out.

   Good luck.

   --Jay

1. 
   Guest_ | Sep 04, 2000 09:36pm | #2

   *Rich,Perplexing. Where is he located? Can you describe the <> a bit more? Damp spots? Noticably darker than the walls? Which walls? (Exterior v interior, North, S, E or W) Any relationship between the spots' locations and windows? Registers?Does he have and use a humidifier during heating saeson? What type of heat & ac? Any particualr weather patterns when it happens? (High wind, high/low pressure, humidity levels.) Any particular time of day?I agree with Jay, at least on the winter end of things, but on the summer end of things its a bit harder for me to envision enough moisture moement thru the walls.Bob

1. 
   Guest_ | Sep 08, 2000 04:18am | #3

   *Rich, Here's one from the archives. There have been a few other discussions as well, but they're probably buried deep...

1. 
   Guest_ | Sep 08, 2000 06:40pm | #4

   *After looking at the archive link and the above problem, here are some (im)pure speculations:Rich - What do you find midway up a drywall partition? Answer - a joint. My guess (unless there is an exterior roofline close to the midpoint of the wall) is that, whatever the moisture problem is, the vapor is escaping at the easiest point - through the horizontal drywall joint. If there is an intersecting exterior roofline, you can get moisture wicked up into the wall under certain conditions of poorly-executed exterior wall construction.Another possibility (thinking about what an 80-year-old house and a house today have in common) is poor insulation/no vapor barrier. The 80-year old house (archive link) may have no insulation, wet basement, etc. Also, it is much more likely to be balloon-framed, with unexpected vertical wall connections between basement and attic, even in interior walls. If warm moist air from an upper space encounters cool rising air from a basment (can happen in interior walls) guess what happens - condensation.The current method of installing fiberglass batt insulation involves stapling the flanges to the inside face of a stud, as opposed to over the face of the stud as recommended by insulation manufacturers. We all know why this is done, yet without an additional vapor barrier over the top and with a lousy insulation job you'll get lots of opportunity for warm moist exterior air to migrate into the wall cavity and condense. A/C could make this worse in the sense that, while it will decrease overall humidity it cools the surface of the interior walls so that they reach dew point more readily. The elusiveness of dew point within building envelopes, results from varying atmospheric and interior RH scenarios and therefore may 'come and go' as described.I hope that these few thought might help you resolve this issue - good luck.Jeff Clarke

1. 
   Guest_ | Sep 09, 2000 05:34am | #5

   *Jeff, I have a certainteed brochure from two years ago that shows stapling flanges to the sides of the studs.Don't expect the "vapor barrier" facing on the batt to do much.-Rob