Don t stuff r 30 into a space that just fits r 19 5 1 2 because you will lose efficiently if you do.
R19 or r30 in attic.
Get free shipping on qualified r21 r30 r19 fiberglass insulation or buy online pick up in store today in the building materials department.
Drill holes in the sheathing and blow insulation into the empty wall.
I believe crushing the insulation together decreases it r value.
R19 r30 r21 fiberglass insulation insulation the home depot.
That said use as much as you can.
Wall insulation whenever exterior siding is removed on an.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
So if r 19 is designed for 3 1 2 and r 30 is designed for 5 1 2 and you still need an inch or so for ventilation of the plywood you need to have at least 10 rafters.
If you use the attic for living space you should insulate the ceiling of the attic if not then do the ceiling of the house itself.