What Do You Use to Hang Crawlspace Vapor Barriers?

Pressure-Sensitive Tape

• Specialized tape seals and attaches the vapor barrier and completes the process of locking out moisture beneath the plastic sheeting used for the vapor barrier. The tape is sensitive to pressure, which means it seals further when pressed against the other surfaces. This tape can be used to seal seams where the plastic sheeting is overlapped, between layers when screws will be placed through the vapor barrier so it seals around the hole and any other place where a hole or gap may occur. The tape's pressure sensitive nature means it adheres better and reduces the chance of gaps in the plastic that allows moisture to bleed through.

Furring Strips

• Furring strips are thin wood strips that attach to a wall surface and give an anchoring point to insulation and plastic sheeting. Furring strips provide a spacer that allows insulation, plastic sheeting or other surface type materials to be anchored to a wall without the material laying directly on the wall surface. The furring strips are attached to the wall first, and the vapor barrier is attached to the strips.

Masonry Anchors

• Nails that can penetrate masonry or concrete serve as vapor barrier anchors. Furring strips and plastic sheeting need to be attached to the concrete foundation, and regular nails are not hard enough to penetrate the concrete without bending or breaking. Regular nails also do not hold as well as they are not designed for this use. A masonry nail has a spiral or ringed design that allows it to grab when placed in the concrete so it will not pull out easily.

Other Helpers

• Galvanized flashing and caulk are two sideline items that can help you hang a crawl space vapor barrier successfully. The galvanized flashing attaches at the top of the foundation wall and provides a barrier to insects and rot. The caulk is an additional sealant that, while it does not secure the plastic vapor barrier sheeting, assists in sealing the vapor barrier to provide a secure and gap-free surface. The more tightly sealed and protected the vapor barrier is at the start, the better it will maintain its integrity and remain intact.