A 20-millimeter thick vapor barrier ranges from 50 to 70 cents per square foot. The tape to secure it costs about $50 for a 4-inch by 180-foot roll. Labor charges to install the vapor barrier will depend on the size and condition of the space.Click to see full answer. Furthermore, how much does it cost to install a vapor barrier in a crawl space?The average cost to install vapor barrier in crawl space can vary significantly depending on the size of the project and the condition of the crawl space. As experts put it, the cost of sealing a crawl space would range between $1,500 and $15,000, with an average cost of at least $5,500 with the help of professionals.Secondly, how long does a vapor barrier last? While thinner plastic or regrind may be OK for short-term use, only reinforced virgin poly should be used for long-term applications like crawlspace vapor barriers. Properly installed virgin reinforced poly should last 20 years or more in a crawlspace. Also to know is, how much vapor barrier do I need? The general rule of thumb with vapor tape is one roll for every 1,000 square feet of vapor barrier.Is vapor barrier necessary in crawl space?Without a vapor barrier, the moisture that comes in through the soil can lead to electrical shorts, which is a fire hazard. That water can also cause your plumbing to rust and eventually break over time. Installing a vapor barrier in your crawl space will keep the area dry and healthy.