mmi door Measure for an Exterior Prehung Door User Manual
- June 9, 2024
- MMI DOOR
Table of Contents
mmi door Measure for an Exterior Prehung Door
Choosing the Correct Prehung Door Size and Handing
What Size is my Rough Opening?
Getting the rough opening size right the first time will save you a lot of
frustration when installing your doors. Framed rough opening sizes are
actually simple. Just add 2” to the width of the actual door size and 2-1/4″
to the height of the actual door size
Why Does the Rough Opening Need to be Bigger than the Door and Jamb? Three Reasons:
- Room to adjust the door and the frame in the opening. Not all rough openings are completely plumb and square. Leaving this extra space allows you to perfectly plumb, level and square your door installation.
- Next, not all doors are the exact same size. The sizes of the door will vary by manufacturer. Normally this isn’t much, but if your rough opening was tight, or exactly the size of the door and the jamb, you may not get the door to function properly without having room to adjust.
- Finally, this leaves room for expansion and contraction of the wall. Yes, your wall gets bigger and smaller as the seasons change. It does this by taking on moisture when it’s humid outside and shrinks when temperature and humidity levels drop.
Again, we are talking about small amounts, sometimes less than 1/16″ of an inch, but this can be enough to make that once perfectly fitting door start to stick, rub on the frame or not latch properly.
Rough Opening Tips
- Verify the width and height of the door frame are each 1/2″ smaller than the rough opening width/height.
- Verify the rough opening is square. The diagonal measurements should be the same. Maximum allowable deviation from square is normally 1/4″.
- Verify the rough opening is level and plumb. The maximum allowable deviation is 1/8″ to 1/4″.
What is my Door Handing?
The easiest way to determine your door handing:
Step into the open doorway with your back to the hinges. You will be standing
sideways in the opening, looking at the jamb side where the door latches. If
the door and hinges are on the left side, it is a left-hand door. If the door
and hinges are on the right side, it is a right-hand door. Simple.
How to Measure Your Rough Opening
- If you are measuring for a new construction, skip to Step 6.
- If you are replacing an existing door, remove the casing or trim from one side of the door open.
- Measure the width of the outside of the jamb in 3 places: top, center and bottom. Record the smallest of the measurements
- Measure the height of the outside of the frame from the floor in 2 places: left and right. Record the smallest of the measurements
- This width and height will be your door’s unit dimension
- Measure the width of the opening from stud to stud in 3 places: top, center and bottom. Record the smallest of the measurements
- Measure the height of the opening from stud to floor in 2 places: left and right. Record the smallest of the measurements
- This width and height will be your rough opening
- Measure the wall thickness, this is the width of the studs. 2”x4” or 2”x6” studs are most commonly used.
a. 2”x4” = 4-9/16” jamb, 2”x6” = 6-9/16” jamb
Download PDF:mmi door Measure for an Exterior Prehung Door User Manual
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>