Vaulted Ceiling Insulation
I am building a ranch house in RI. The house is 2400sqft, has SIP walls and is a slab on grade with radiant. My question concerns insulating my vented, vaulted ceiling. My living room is made with scissor trusses and has a 12″ energy heal (inside the 9′ SIP walls). I have had a few insulation companies come and give me an estimate on insulating the ceiling and I have as many recommendations on how to do the vaults. One company wants to do 12″ of fiberglasswool batts; another wants to do cellulose and yet another insists on rock wool. My truss engineer suggests that I go with cellulose but use scrap plywood or OSB to make little dams every 4 feet or so running across the cathedral slopes to prevent the cellulose from falling down to the walls and possibly obstructing the soffit vents. Oh yes…the rock wool guy insists that the rock wool will not fall down the slopes due to it’s weight, does not need a vapor barrier and guaranties everything for life…I am skeptical to say the least. What do I do?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part