I have a garage with an odd size entry (not bay) door. The old door, which recently broke, was only 24" x 70".
Time to put in a new door. My intent is to enlarge the opening for a more standard size. I expect this will be cheaper while also improving the structure. In fact, I can see the space where there was once a wider opening… it measures at 36" rough, which would have fit a 34" door. It should be very easy to restore this old opening, and I can get a 34" x 80" prehung door at a reasonable price.
No word yet on why a previous owner put in such a weird door ¯\_(ツ)_/¯
The problem is the height. My understanding is a 34" x 80" door needs a 36" x 82" rough opening. The entire height of the garage wall from the concrete to the bottom of the beam is only 81 3/4".
Will I be able to make the standard door fit, or will I need to do something custom? If it will fit, will I need to do anything extra to make it work?
Best Answer
Checking online there are the actual unit dimensions for these doors on the "Big Box" websites. I am finding the actual sizes are 81 5/8" in many cases. Tight for your opening but a little off the header will get it in. As a note, this is for an exterior door. Typically interior doors are perhaps a 1/2 shorter. If the header needs a 1/4" taken out of the bottom, and you have a 2x6 header for a 36" rough opening, there will be no issue. The sheathing on the wall outside aids in supporting the surrounding framing.