It is the dense packing of unvented cathedral ceilings or unvented flat roofs that is the problem.
Dense pack cellulose insulation cathedral ceiling.
There will be plenty of insulation packed at the right density.
Cellulose is treated with borate a harmless naturally occurring mineral that has the ability to deter bugs.
This makes it much more difficult for air to move through the insulation.
Energy saver suggests dense packing cellulose to insulate this cathedral ceiling where air flow will now be interrupted and insects and pests will be unlikely inhabitants.
In fact dense packing walls typically results in remarkable performance.
First the good stuff.
By filling the entire cavity with a dense pack you get the highest insulation ratings fiberglass or cellulose can achieve.
First cellulose has a natural density about two times that of fiberglass batts and four to five times that of loose blown fiberglass.
So bees ants and termites won t find that ceiling so inviting anymore.
You achieve the maximum insulating capacity.
The insulation will continue to keep the cavity filled.
At 3 5psi the insulation will not settle and create gaps.
Advantages to dense packing.