Question: Which Vapor Barrier Should I Use for My Crawlspace to block mold? I need to replace the vapor barrier in my crawlspace. Having been a mold victim in the past I don't want to use the cheap stuff from a big box hardware store. What do you recommend?
Answer: Thank you for sending us your question. First I would like to commend you for knowing that the plastic sheeting sold in most hardware stores is not ideal for this application. My top recommendation would go to an engineered plastic sheeting that passes at least some level of the ASTM E-1745. These materials are tested such that they will not degrade when in contact with soil, plus pass a number of other important criteria, like puncture strength and water vapor transmission rates. Most customers prefer a white liner in crawlspaces, because it brightens the space and makes it look really nice. Our top pick is the VaporBlock 20 Plus, a 20 mil white/gold product that blocks virtually all of the radon, methane, VOC's and does an excellent job with water vapor. If you want to stay with a material that is white on one side consider Dura Skrim in 8, 12, and 20 mil versions, plus our Crawlspace 1800, 18 mil reinforced crawlspace liner material. Any of these do a nice job in crawlspaces. The heavier materials are usually used for the floors, and the lighter materials for the walls and columns. If one is just concerned with water vapor transmission, then the VaporBlock line of products is pretty hard to beat in today's marketplace. The 10 and 15 mil versions are blue in color, and pass Class A,B,C of the ASTM E-1745. We also have 2 versions of the 6 mil available, a 6 mil blue, and a 6 mil VaporBlock Plus, both pass ASTM E-1745 Class C. The VB6 Plus is currently being closed out as the plant has decided to discontinue this product. The tapes used are also quite important to the finished crawlspace. We have 4" wide seaming tape made specifically for this application, called Vapor Tape, Rolls are either 4" x 180' or 4" x 210'. For sealing along the top and around protrusions, we supply a double-sided Butyl Rubber, Reinforced Tape we feel is the best in the industry. Rolls are 1.5" x 100'.