The first time I heard about wet-spray cellulose, I wanted more information — it sounded too good to be true. But as I sat in my first informational meeting about wetspray cellulose, I became a believer. Advantages of Wet-Spray Wet-spray cellulose has a slightly higher R-value than fiberglass — blown onto a 2x6 wall, it gives you about an R-21 (compared with R-19 for a 6-inch fiberglass batt). But more important, wet-spray cellulose fills in around wires, blocking and everything else, leaving no voids. By doing so, it effectively eliminates air infiltration and air movement in the stud cavity in the same way that sprayed-in foam does, but at a much lower
