Tim the Termite Guy

Hi again Fellas, I've been in the termite biz for about 5 years mainly doing inspections. Granted, some of you have more field experience than I, and I am always willing to listen to reason, but reading through the posts it sounds like everyone has a different take on this. Maybe there is no "one size fits all" answer. When I see big gaps in vapor barriers What comes to mind is poor workmanship, and I've seen my share of sloppy vapor barriers. Sometimes they get wadded up and drug around too. I suppose as long as the water is recondensing on the underside of the plastic, then it benefits the substructure by helping to lower the moisture content of the wood thereby reducing it's palatability to wood destroying organisms. The guy that originally trained me was an old timer who knew alot and probably one of the first to start putting them in around here. His preference was to let the subarea soil "breathe" at least a little. Thats one reason why I like to leave a bit of dirt showing along the foundation. Another reason is in case some runoff does occur it can percolate away. And then there came the fateful day I popped the hatch on a old house to inspect the crawl and the soil was right there at the bottom of the joists. Evidentally the house had settled to the point where you couldn't get under it. That got me wondering: if the soil stays softer, the house sinks quicker? hmmm. Tim http://timthetermiteguy.com

California regulations state a vapor barrier has to cover 80% or more of the subarea soil with 4 mil or thicker poly. I personally like 6 mil black poly. After inspection I usually cover as much of the subarea as I can access leaving about a 4" to 6" gap adjacent the foundation so the soil can breath at least a little. My concern is what might happen over time to a foundation in expansive soil that is always wet on one side and seasonal on the other. I've seen old houses where people over-irrigate causing damage to the foundation, hmmm.... Another concern is the presence of standing water. You don't want to create a permanent pond under your house.