View Single Post
Old 04-27-11, 07:44 AM   #22
S-F
You Ain't Me
 
S-F's Avatar
 
Join Date: Nov 2009
Location: Northampton MA
Posts: 662
Thanks: 6
Thanked 71 Times in 58 Posts
Default

Dense pack will never loose R value as it's beyond settled density. Loose fill will though. There are two measurements for it's R. One is new and one is settled. These foams are showing to loose considerable R value over time. Much lower than their spec. The gasses continue to escape into the air. It just takes some time. Maybe 20 or more years. But most people building these days only think about the next decade at most. The hygroscopic value of cellulose is very good. It moisture levels. It doesn't absorb it and hold it unless it's soaking wet. It will facilitate drying of all of the structure. The foam rejects moisture forcing it into the lumber. This is a great plan for rot. In such a house humidity will need to be carefully controlled and kept to a minimum.
S-F is offline   Reply With Quote