How do I put a vapor retarder in my crawl space?

Question

I live in Michigan and the house my husband I bought dose not have a vapor retarder in the crawl space. We have cross vents, but this summer we have noticed a musty smell in our house and the crawl space. Our vents are open in the summer and closed in the winter, but we were told that we need to put some kind of a vapor retarder in the crawl space. How do we go about doing this, and what do we use? Also we were told that there are codes to follow according to your state and county. If anyone knows what codes there are for Michigan please let me know. THANKS!

Answer 1

What you need is a vapor barrier on the dirt flooring. Use at least 6 Mil plastic sheeting and overlap joints by one foot and tape them. You can also run it up the sidewalls a foot or so. This keeps moisture from rain out of the main area. This is probably where the smell originates. If you do the floor joists, the barrier goes tight against the flooring. If you do the dirt floor, you will probably not need this.

Answer 2

If the studs are exposed in the crawl space you can put a vapor barier over the studs then sheetrock it. If the studs are not exposed then you could spreay a sealer around the area that has gaps were air goes through Good Luck