How to Determine Rough Opening Size
Our Quick Door Hanger brackets are made for installing doors into standard rough door opening sizes. Nothing special needs to be done for rough door openings. There is no difference if you use our Door Brackets or Shims.
Standard Rough Opening Sizes
Rough door opening sizes are standard among builders. The way this is determined is, take the desired pre-hung door size (door size not including the frame) and simply add 2" to the width and roughly 2.5" to the height. That's it. This extra 2" gives room for the door's frame as well as a little extra play for getting the door perfect.
1. If you have a 32" wide rough door opening, that means you need to purchase a 30" pre-hung door.
2. If you purchased a 2 ft 6 inch wide door, then you need to have a wall rough opening of 2 ft 8 in.