I'm about to replace the back service door to my garage with a prehung steel door. I just went with an off-the-shelf prehung door because it's on the back of the house so it doesn't need too look nice, but the rough opening is an odd size and I'm NOT about to order something custom sized...
The actual rough opening height is 81-1/8 to 81-1/4 at the corners due to either settling or an inaccurate level from the original builder.
My question is this: can I safely trim away some of the 2x4 frame at the top of the rough opening even though the header sits on the 2x4, which sits on the jack studs, leaving the ends fully intact? My idea was to just make 1/4-1/2" deep slices with a circular (or other) saw and chisel out the bits to make the opening just large enough to fit the door.
(I tried to upload a photo or insert a link to a photo, but apparently I need ten posts to be able to do that, so use your imagination I guess..)
Since the garage floor is cement, it's not likely that I'm going to be adjusting it down any further...
Thanks in advance for your time.