[BILL BOWMAN1]

I’m going to be adding some insulation in my attic this fall. It currently has the cheap builder grade blown in type. A lot of it is just disintegrated or collapsed down to nothing. I don’t wanna go with the blown in route because I will lose all that usable storage space.
I was going to get the rolls and just apply on top of the little thats left there. I’m guessing they’re either 2x6 or 2x8 ceiling joists. I’m a little confused on R value, and faced or non faced.
I guess at this point anything will be better than what’s up there.
Central east coast , hot and humid summers.
Thanks.

[tooski]

Just a diy'er. I insulated two new builds I've lived in, a couple of garages, and renos on rental properties. I've only ever used batt insulation. My place in AZ has blown in the attic. I hate it when I have to go up there. I can't move around without fibers floating around. Once installed, it's not a problem with the batts. Rolls are basically the same, just one long roll cut to length as opposed packaged bats with a specific length and width. Easier to handle than cutting up a long roll. Generally speaking a 6" bat is R20. Put them in a 2 x 6 (5 1/2) wall stud space and it's R19. You can buy a R20 or R22 for that 5 1/2" but a bit more expensive. In the ceiling, you are not governed by lumber width. 8' thick bat is about R30, 11" is R40. Code in my area requires R40 minimum. Bats usually come in either 15"or 23" widths. If you live in a older house with constructed rafters they may be 2 x 6. I've not seen more than 2 x6 rafters. Modern manufactured and engineered trusses are usually made with all 2 x 4's. Any truss company will use the dimensional lumber you request. I've had a couple built with the horizontal piece built with 2 x 8 so I can put install an 8" bat (garage) and put an osb 'floor' on top and not crush the bat to a thinner (ie less R value) thickness. Btw all the lumber sections in a manufactured truss are called 'cords'. I have seen trusses with some of the cords made with 2 x 3's, obviously to save money.

[Redpiston]

You aŵill want to use unfaced bats. The facing is a vapor barrier and will trap moisture.

[West Coast GTO]

The top and bottom components of a truss rafter are called the top and bottom CHORDS. The connecting pieces that attach the top and bottom CHORDS are called webs. Trusses are engineered to perform dead load support and have not been engineered to support additional loads of " storage items" that a home owner may want to add. If excessive weight is added to an existing truss structure that has not been engineered for the load, problems MAY occur. Good luck.

Originally Posted by tooski

Just a diy'er. I insulated two new builds I've lived in, a couple of garages, and renos on rental properties. I've only ever used batt insulation. My place in AZ has blown in the attic. I hate it when I have to go up there. I can't move around without fibers floating around. Once installed, it's not a problem with the batts. Rolls are basically the same, just one long roll cut to length as opposed packaged bats with a specific length and width. Easier to handle than cutting up a long roll. Generally speaking a 6" bat is R20. Put them in a 2 x 6 (5 1/2) wall stud space and it's R19. You can buy a R20 or R22 for that 5 1/2" but a bit more expensive. In the ceiling, you are not governed by lumber width. 8' thick bat is about R30, 11" is R40. Code in my area requires R40 minimum. Bats usually come in either 15"or 23" widths. If you live in a older house with constructed rafters they may be 2 x 6. I've not seen more than 2 x6 rafters. Modern manufactured and engineered trusses are usually made with all 2 x 4's. Any truss company will use the dimensional lumber you request. I've had a couple built with the horizontal piece built with 2 x 8 so I can put install an 8" bat (garage) and put an osb 'floor' on top and not crush the bat to a thinner (ie less R value) thickness. Btw all the lumber sections in a manufactured truss are called 'cords'. I have seen trusses with some of the cords made with 2 x 3's, obviously to save money.

[BILL BOWMAN1]

Thanks all, that helps a lot!!
The “storage” is by no means heavy, just normal household clutter.

[burd]

If you don’t know what your doing, get a company to do it.

[tooski]

Originally Posted by West Coast GTO

The top and bottom components of a truss rafter are called the top and bottom CHORDS. The connecting pieces that attach the top and bottom CHORDS are called webs. Trusses are engineered to perform dead load support and have not been engineered to support additional loads of " storage items" that a home owner may want to add. If excessive weight is added to an existing truss structure that has not been engineered for the load, problems MAY occur. Good luck.

Thanks for the spell check and nomenclature corrections.
My building inspector also said attic space is for minimal storage, maybe a boat paddle or two.
My luck has been very good.

[dataway]

Try "Rock Wool" insulation. It's hydrophobic, easier to work with, not as irritating, fire-proof, all around better than the pink stuff.

[sdbob]

What we always did was fill void between ceiling joist with thickness of fiberglas insulation that comes up flush with joist,facing towards heated room then take thicker fiberglas unfaced insulation and go across that. In your case maybe unfaced in void.

[Ashley P]

Blow in can be fiberglass or cellulose....right? If I ever get that far in my remodel, I plan to blow cellulose in my attic. I have walk boards and a platform built a foot above the ceiling for storage after insulation.