What’s the black plastic for?

• Posted on August 15, 2016
• by mikew
• in Fix It & Use It
• No Comments.

The black plastic in crawlspaces are called vapor barriers. Vapor barriers have two purposes for a home. First, they reduce ground moisture from entering the crawlspace. Our goal is to keep moisture less than 20%. Second, they provide a timeline of crawlspace activity. Plumbing leaks, rodent activity, ground water issues, repairs, and previous inspectors all leave tell-tale signs of their visits on the black plastic even years after the event. Here are some things that the black plastic help you and us inspectors see…

…Insulation is intact and secured between the flooring joists rather than lying on the ground.Cable and wires secured to the crawlspace ceiling and out of the way. Plumbing is dry with no signs of leaks and water stains on plastic below. Any tell tale signs of rodents – their droppings are pretty distinctive not to mention their smell! Past repairs that have been made.

I always recommend that a new vapor barrier be installed (or the old one thoroughly cleaned) if there is an extensive amount of dirt, debris or stains present. This will provide a fresh slate to begin the history of your home in the months and years that follow.