With winter just around the corner, consider getting a head start in maintaining the comfort of your home. Fallen, sagging, or absent basement and crawl space insulation create uncomfortably cold floors and higher energy bills.
Here are two very different ways of insulating your crawl space in the Johnson City, TN and Abingdon, VA area, and what you should expect to see with each method:
1. R-19 Fiberglass Insulation (Vented Crawl Space)
An R-19 fiberglass batt or roll insulation is the most traditional and cost-effective way to insulate your floor. In Climate Zone 4 (most of Tennessee and southern Virginia), the fiberglass batt should have a paper facing on one side that is installed facing the floor of the home. You should see pink/white/yellow insulation facing the ground. Insulation batts are held in place between floor framing members with insulation support wires every two feet.
A vapor barrier or ground cover should cover the floor of the crawl space to prevent moisture problems and to keep humidity levels low. A vapor barrier, typically 6 mil plastic, will keep mold out and ultimately improve the indoor air quality of your home.
Depending on the square footage and difficulty of installation, among other variables, insulation in the floor of your home may cost anywhere between $0.55-$0.75 per sq. ft.
2. Unvented Encapsulated Crawl Space with Spray Foam Insulation
An encapsulated, “un-vented,” or “closed,” crawl space seals the walls and rim joists underneath your home from the outside environment.
It is important to use closed cell spray foam in your crawl space because it performs as a moisture barrier when applied to at least 1-1/2″ in thickness. Closed cell spray foam insulation expands roughly 40x its liquid state to fill every crack and crevice in your foundation walls, all while achieving an R-value of about 7.0 per inch.
Like vented crawls, at least a 6 mil vapor barrier is installed on the ground to prevent moisture migration.
Un-vented crawl spaces are an extension of the conditioned space in your home, keeping water lines, water heaters, and mechanical utilities in a conditioned space. This is great from an energy consumption perspective – your utilities aren’t exposed to extreme cold weather in the winter.
In addition to completely sealing your crawl space, closed cell spray foam insulation will help keep pests like snakes, skunks, spiders, mice and termites from the underside of your home!
Un-vented crawl spaces are generally considered to perform better than vented crawl spaces in terms of energy consumption, comfort, and health. In east Tennessee, an encapsulated crawl space sealed with closed cell spray foam may cost anywhere between $2,000 and $10,000, depending on the size of the home and the height of the crawl space foundation walls.