Basement Remodeling & Vapor Barriers

Identification

• According to the United States Department of Energy, vapor barriers should be part of moisture control strategies for homes in the United States. Vapor barriers are also known as vapor diffusion retarders, which are constructed of material that reduces the rate at which moisture moves through walls, ceilings or foundation floors. Just how effective vapor barriers are is measured in "perms," or permeability. To effectively minimize moisture, vapor barriers must have a permeability rating of less than 1.0.

Uses

• Vapor barriers are an important part of moisture control in basements, floors, walls, ceilings, slab foundations and crawl spaces. The type of vapor barrier used during basement construction or remodeling depends on the climate you live in and the style of construction. To keep moisture and humidity levels low inside your basement, installing a capillary break and vapor barrier over at least 4 inches of gravel is an effective way to control moisture.

Types

• Vapor barriers can take many forms, but most are thin membranes or coatings. According to the United States Department of Energy, membranes are typically flexible materials constructed to repel moisture. Foam boards are rigid insulation panels and are excellent vapor barriers. Coatings are usually painted on the walls and ceilings. In mild climates, any type of paint can work as a vapor barrier as long as multiple coats are applied.

Installation

• Adding vapor barrier membranes such as sheet plastic usually requires extensive remodeling. However, adding paint as a vapor barrier works well except in extremely cold climates. Choose a paint with a high percentage of solids and apply multiple coats for thickness. Glossy acrylic paint is a more efficient vapor barrier than a flat latex paint. The more coats of paint you add to your basement during remodeling, the more effective the vapor barrier.