To hit code minimums you ve got to add new insulation on top of the old insulation.
Cellulose insulation in attic ceiling.
This reduces settling and decreases the amount of cellulose needed.
This video shows a diy cellulose insulation install in a cathedral ceiling in a new house construction that has limited accessibility crawl space was 18 5.
You can get to the same place with either material.
Assuming your current attic insulation is made from fiberglass and has a value of r 13 you d have to add roughly 10 inches of additional fiberglass to hit r 38.
Blown in cellulose has a higher r rating and is less expensive than either blown insulation like fiberglass attic insulation or fiberglass batts.
Stabilized cellulose is used most often in attic roof insulation.
When it comes installing cellulose the usual advice is to pile it on.
Blown in cellulose is an environmentally friendly material made from recycled newspaper so it s easier on your skin and lungs.
It is applied with a very small amount of water to activate an adhesive of some kind.
This can prove advantageous at reducing the overall weight of the product on the ceiling drywall helping prevent possible sag.
Or 7 inches of cellulose.
Cellulose blown in ceiling insulation is a good choice for diyers.