Replies

1. 
   matthew25 | Apr 23, 2023 12:32pm | #1

   As long as you don’t have any restrictions for the thickness of the loose-fill, cellulose or fiberglass are going to be your most cost-effective options.

   You should walk around the attic with a couple of cans of spray foam to air seal any penetrations in your drywall ceiling first while you have the opportunity. You can use a blower-door to find the leaks easier.

1. 
   bauchin | Apr 23, 2023 06:25pm | #4

   Thanks for your reply . . . the only restrictions I have for the thickness are the access path down the middle of the trusses just in case I need to get up to the attic (there is no equipment or ductwork in the attic so it would only be to check the roof above). I might just use Rockwool batts under the minimal walking access path but not sure if there is a better way?

2. Expert Member
   MALCOLM TAYLOR | Apr 23, 2023 01:33pm | #2

   Blake,

   On of the big advantages of cellulose is that it has good resistance against wind washing, which can degrade the R-value of other loose fill insulations.

1. 
   bauchin | Apr 23, 2023 06:26pm | #5

   Thank you for that feedback!

3. 
   rockies63 | Apr 23, 2023 04:42pm | #3

   The more critical thing will be air sealing the attic from the house. How are you going to deal with any pot lights or ducting?

4. 
   bauchin | Apr 23, 2023 06:28pm | #6

   Not putting any ductwork or recessed lighting in the 2nd floor ceiling so only have to deal with sealing electrical junction boxes for the surface mounted fixtures below. All ventilation ducts come up through the walls to wall registers - none in the attic ceiling. Thanks for the question

1. Expert Member
   BILL WICHERS | Apr 23, 2023 07:39pm | #7

   Use the fiberglass “hard boxes” instead of metal or plastic boxes. The fiberglass boxes don’t have any holes in them — the knockouts are thin spots you can poke out as needed — which means much easier to air seal.

   Bill

1. Expert Member
   MALCOLM TAYLOR | Apr 23, 2023 08:09pm | #8

   Bill,

   Or the Rolls-Royce of sealed boxes invented by GBA contributor Doug McEvers: http://airfoilinc.com/products/products.html