Replies

1. 
   rjw | Jan 01, 2010 07:16pm | #1

   Moisture problems showing up in the attic usually/often reflect moisture problems in the basement/craw; space.

1. 
   ccampbell | Jan 01, 2010 10:23pm | #2

   Nothing major has changed, however, except the new windows. The basement is relatively dry, unless it rains heavily for a couple of days. The foundation is in good shape, with good drainage. So I think the moisture is coming from living in the house - showers, cooking, etc. The problem is just showing itself worse this year because of the windows. At least that's my theory. Not sure what to do to fix it.

1. 
   Matt | Jan 02, 2010 10:12pm | #11

   " The basement is relatively dry, unless it rains heavily for a couple of days. " Sounds like a problem to me....

   Also, be sure all your bathroom exhaust fans and kitchen hood fan are vented to the exterior, working properly, and they are used.

   You really need to get this resolved before finishing off the attic.

1. 
   ccampbell | Jan 03, 2010 02:15pm | #12

   There isn't a basement in my
   There isn't a basement in my neighborhood that is bone dry after a long heavy rain. These houses were built in the early 1900's and have stone foundations and egg shell floors. Mine is actually quite good for the area. I have a workshop and exercise area down there. It's very usable. However, if it rains long enough, the water table rises and pushes a little water up through the floor. Nothing I can do about that that I'm aware of.

   The bathroom fan is vented to the outside, and we use it religiously. We don't have a fan in the kitchen. Our range is on an inside wall and it would require surgery to add one.

2. 
   MHolladay | Jan 02, 2010 06:49am | #3

   Chris,
   If you haven't located
   Chris,

   If you haven't located the air leaks between your interior and the attic, it's time to call in the professionals. You need a home performance contractor equipped with a blower door.

   Martin Holladay, senior editor

   http://www.greenbuildingadvisor.com

1. 
   Matt | Jan 02, 2010 10:05pm | #10

   Martin:

   Care to comment on my q over in the Green Building folder re gas ranges and indoor air quality?

3. 
   Honeymoon | Jan 02, 2010 09:23am | #4

   First big ? no one has asked..........is your attic properly vented in order to dissapate moisture to the exterior??

   Typically, the big sources of moisture in a home are bathrooms, and kitchens. Where and how is the moisture from these rooms being removed from the structure>

   Perhaps you have a dirt floor in your basement or crawl space? If so you need to cover it with a vapor barrier.

   The moisture is being created someplace, and it needs a place to go (outside) and a way to get there. It's not brain surgery.

4. 
   DanH | Jan 02, 2010 09:25am | #5

   If you weren't going to
   If you weren't going to convert your attic, the solution to the frost problem would be ventilation.

   If you convert it, however, you've got fair warning that you need (in a conventional "cold" roof) a vapor barrier and good ventilation in your attic ceiling.

1. 
   rjw | Jan 02, 2010 09:29am | #6

   >>If you weren't going to
   >>If you weren't going to convert your attic, the solution to the frost problem would be ventilation.

   Venting is important, but I've seen unvented attics without visible moisture problems.

1. 
   ccampbell | Jan 02, 2010 10:30am | #7

   Now we're getting down to
   Now we're getting down to what I was after. :) I have no attic ventilation. These little old bungalows in my neighborhood weren't built with ventilation - you were just supposed to open a window if need be. The houses were so leaky it didn't really matter. I want to convert the attic however, because it's a great space to be claimed in my little house.

   So what happens to all this moisture then? I assume I should continue to try and seal up as many penetration spots as possible between the upstairs and downstairs. Do people use spray and caulk on the light fixture electrical boxes and on the can lights from the kitchen? The boxes and can housings have openings in them of course, not to mention just the gaps between them and the plaster.

   When it comes time to insulate the roof for the conversion, I'm thinking I need spray foam to block the moisture? I don't have soffits for there to be air flow across the roof surface.

2. 
   DanH | Jan 02, 2010 10:45am | #8

   I'm sure you have. Many
   I'm sure you have. Many attics are so poorly sealed against the weather as to be "self-ventilating", and in other cases the moisture sourcing from below is negligible. But neither is normal.

5. 
   IdahoDon | Jan 02, 2010 05:32pm | #9

   Insulate rafters with rigid foam or sprayed in foam and you don't have to ventilate and your problem goes away.