Replies

1. 
   Jim_Tredeau | Dec 18, 2000 03:45am | #1

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   Is your vapor barrier on the bottom of the joist or on the top side of your joist? Vapor barriers should always be placed on the warm side, which in you case it should be placed against your sub floor (the top side of your joist). You should also have at least a 6 mil. (black) poly vapor barrier covering the ground in your crawl space. I hope this helps.

1. 
   Darren_Thomas | Dec 18, 2000 04:13am | #2

   *Thanks for your response Jim, current vapor barrier consists of insulation paper towards the heated space. Thanks for your insight.

1. 
   Jim_Tredeau | Dec 18, 2000 04:39am | #3

   *Where is this building located? Do you have a vapor barrier covering the soil in the crawl space?

1. 
   Darren_Thomas | Dec 18, 2000 04:47am | #4

   *The house is in NE PA. Currently no vapor barrier on the ground.

1. 
   Mike_Smith | Dec 18, 2000 06:05am | #5

   *check this out... it's about 10 threads down from here....http://webx.taunton.com/WebX?50@@.eebeb6e/19a better solution...

2. 
   Gene_Leger_ | Dec 22, 2000 11:37pm | #6

   *Darren. Insulating between the floor joists and placing the vapor barrier(sic)against the floor sheathing does nothing to keep moisture out of the crawl space. You didn't say if the crawl space is ventilated. GeneL

3. 
   Jim_Tredeau | Dec 23, 2000 03:26am | #7

   *Gene, The vapor barrier should be placed against the sub-floor so it will not trap moisture between the floor joist. It is the same for the crawl space as it is for the attic, you wouldn't place the vapor barrier facing the attic space either.

4. 
   Bob_Walker | Dec 24, 2000 02:31pm | #8

   *IMHO, Insulate the foundation walls, block the vents, plastic the ground, and condition the space. Don't forget to minimize moisture in the crawl with positve grading around the house and long downspou extensions. (Works well in NW Ohio, similar climate to NE PA)Read the thread Mike linked to.

5. 
   Gene_Leger_ | Dec 26, 2000 11:25pm | #9

   *Jim. Im general you are correct. however, there are instances when your rulke doesn't apply. In summerime the exposed insulation and fram ng must be protected from wetting. Here rigid foam board insulation (RFBI) must be installed on the bottom of the floor joists. The joints must be taped/sealed.Another instance is when a pier foundation is used. The framing and insulation must be protected against moisture. The RFBI must be firerated if it is left exposed. Bob Walker gives some good advice. GeneL

6. 
   FredB | Dec 28, 2000 08:01am | #10

   *Here's a second for Bob's recommendation. With Rare exception the goal is to keep outside moisture outside. You do that by adequate drainage, grade and barriers next to the outside(soil floor) when needed.

2. 
   Darren_Thomas | Dec 28, 2000 08:01am | #11

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   My home is a 1100 sq. ft. cottage built on a crawlspace with block foundation. At the time of construction I was told that a vapor barrier would not be necessary that the vapor barrier on the insulation would be sufficient. Now after 2 years I'm am finding moisture build up on the joists and block walls. I'm currently drying the area with bullet heaters and when completed will install a vapor barrier. I would like to hear some opinions on where to install. On the Ground or on the Joists? Thanks