First the good stuff.
Dense pack cellulose insulation cathedral ceiling.
There are several major advantages to dense packing completely filling a cathedral ceiling cavity with cellulose.
One of the most effective ways of dealing with existing uninsulated frame walls is to blow cellulose into the wall cavities.
For a faster more affordable solution to the cathedral ceiling problem dense pack cellulose insulation can be blown into the ceiling s rafter bays through access points along the roof eaves or roof ridge.
There will be plenty of insulation packed at the right density.
Advantages to dense packing.
You achieve the maximum insulating capacity.
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.
By filling the entire cavity with a dense pack you get the highest insulation ratings fiberglass or cellulose can achieve.
The insulation will continue to keep the cavity filled.
It is the dense packing of unvented cathedral ceilings or unvented flat roofs that is the problem.
In fact dense packing walls typically results in remarkable performance.
At 3 5psi the insulation will not settle and create gaps.
This makes it much more difficult for air to move through the insulation.