Hello Rwitt6745, the rough opening is 221/2 x 301/2 .
There are 8 total mounting slots on the inside lip. Each slot is positioned approximately 1 3/8" from each inside corner
I found this panel to be 22.5" wide. One option: Plan for a larger opening, but order for pick-up at Home Depot first, and then measure the panel at the store before taking it home.
Possibly if you cut the insulation on an angle at the edges. What I did was surround a square of insulation, attached to a board, both the size of the opening with some radiant barrier plastic (so no moisture can get trapped inside). Then stapled some ribbon to it to act as handles, then used the handles to pull it down snug into the framed hole that secures the panel. Now if I need to go up I open the door and push the insulation square up into the attic and when I leave just pull it back in with the straps. I wouldn't want to pull open fiberglass down towards me when I had to open it if the insulation was attached to the door...I can just imagine fibers falling into my eyes
It seals quite tightly, there is no weather stripping. It might be possible to add some very thin rubberjc, but it might keep the door from closing properly. We added some foam insulation to the inside of the door to reduce heat loss and that has worked very well.
Yes, that's what I got it for. Above it I made a "shaft" through the insulation and then made an insulated cover for the haft to maintain the insulation envelope.
The dimensions are of the frame, the flange is about 1/2" larger.
Yes, you can remove the door and frame rather easily. With the door open the frame is generally held in place with 2 or 3 screws on both the left and right side of the frame. The screws would have been affixed to the studs in the structural wall. If you remove these screws the frame, and door, should be easily removed.
They are on the 30" side
This product has a 10-B rating.