Typically, air flows from the bottom of the home to the top. Sure enough, your crawl space is an arch target of this humidity attack. Because it’s close to the ground, it directly absorbs evaporation of moisture from the earth. Moist crawlspace air – and everything in it – is sucked up into the living areas of the home. Mold spores, odors, crawl space moisture, insects, and animals are part of them creating a very unhealthy environment. In cases like this, you should be prepared to stop the onslaught. This is where vapor barrier in crawl space comes in handy. Read the rest of this entry »

We received a call from John in Ohio who is installing his own crawlspace vapor barrior and was not sure how to fasten it to the walls.  Do you know the easiest way to fasten your plastic vapor barrier so that it works properly?

We found several solutions to this problem.  Click the diagram on the right to see the ideal positioning of the moisture barrier.

Here is a vapor barrier movie showing you how to stake down the plastic sheeting.  Notice, his moisture barrier does not go up the sides of the wall.   You will observe that in the video the vapor barrier only goes to the edge of the wall, while the picture shows the polyethylene being attached several feet up the wall.  Depending on your particular crawlspace and personal preferences, you can do it either way.  If you choose to go further up the wall however, be sure the wall is dry before attaching the plastic sheeting and be sure not to attach it to wood posts or studs because moisture will become trapped and then you have the potential for wood rot.

If needed, run your Dri-Crawlspace Dehumidifier^® for a day or two to dry out the walls and surfaces before attempting to use tape or adhesives on the crawlspace walls.

The seams in your vapor barrier should overlap by 6 inches and be sealed with builder’s tape or construction adhesive to form an airtight barrier.  You can seal the edges of the vapor barrier to the foundation walls with construction adhesive.  When it is completed, weigh down your vapor barrier with sand or stones to help prevent ground moisture from escaping into the crawlspace and to help protect the polyethylene from tearing when walking on it.