Can you help with with installing a replacement aluminum window with nailing fins?

Question

I took out the trim and removed the old wooden window. The new window is the same size but I can't get it inside the frame because of the nailing fins. I've tried looking at the website and other website but it's really confusing. I can't understand the pictures at all. Am I suppose to fold over the bottom nailing fin and fold the sides over and nail it to the frame or cut into the window frame to get the window in there? I didn't think it would be this confusing..please help?

Should I just cut off the nailing fin? Can't return it, already painted the darn thing... :-/

Answer 1

OH THIS IS SO EASY !
Remove the fins, and screw the window in from the jamb. The fins will have creases. If you work the fin back and forth it will easily break free. Then install the window as you would any retrofit. Shimming is always necessary.

Answer 2

I'm not sure, because I'm not looking at the window, but are you sure it isn't new construction window. Maybe you can just use the nailing flange, like a new construction window. There will be a bit of ledge which will make putting new trim on more difficult, but you can shim the new trim out or cut a rabbit in the back of the new trim. It would be easier and safer for the window than trying to remove the nailing flange. But don't cut the old window frame.

Answer 3

Those are new construction windows. If you can return them and get replacement windows it will be alot easier to install. If you cant return them and you have vinyl siding then you may have to remove the siding around the windows in order to properly install the windows.

Answer 4

You probably got a New Construction window when you should have gotten the Retrofit (not sure that's what they call it). Retrofit won't have nailing fins.

Answer 5

Cut into the window frame. Nevermind, I don't know.