If you're planning on keeping the plywood there and not moving it much, that's one thing, but if you're using this as a temp solution, get a 2x8 or 2x10 and cut it into two or three 30-36" long pieces. It'll be lighter and much easier to move than plywood.
oh yea the plywood is just gonna be so i can have a flat surface to work on, i think i'll on my belly, especially at the edge where the roof makes that slope, whatever it's called?
What are your goals for replacing the insulation? More temperature barrier between attic and living space?
since i had the numbers, blown in cellulose is 3.8 r-value per inch, so you got like r22 to r30 (lets be safe and just say r22), so look at what the batts would offer you.
Insulating and air sealing aren’t mutually exclusive, but it seems like your insulation is fine so what you really want is sealing foam. I’m not sure if there’s a good way to pressurize your house to make air movement super obvious, but basically any penetration between the ceiling and the attic is going to leak air. Spray foam is extremely flammable so read the directions before spraying around light fixtures and never ever near open flame (pilot lights, for example). The nice thing is you can get cans of sealing foam at your local Lowe’s/HD for a few bucks per can. You want to use it all in one sitting though as the foam cures in the straw and is only good for one-time use.
since i had the numbers, blown in cellulose is 3.8 r-value per inch, so you got like r22 to r30 (lets be safe and just say r22), so look at what the batts would offer you.
For reference i'm in kansas zone 4 and i have 12-15inches of blown insulation for r45
If you really want to use the can more than once/across multiple sittings, the spray gun (~$45) with petroleum jelly and the gun cleaner/acetone might work, but no promises that the nozzle on the can itself won’t permanently seal shut. I’d never advise poking and prodding a pressurized vessel...
Also, you can technically use foil backed HVAC tape (for the love of god, not duct tape) to air seal, but a can of spray foam with a straw is much MUCH easier to use, especially since you’re gonna be working around blown in insulation.
imo, figure out how much sq/ft you need, if you don't know the sqft of your attic use this tool and plug in your address
Because air is what insulates and blown in has way more air within it than tightly packed/compressed rolls. Insulation that’s being compacted loses most of its insulating value.
