Dimensions Guide
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How to Measure for an Exterior Prehung Door 
A pre-hung door is a door that is already hanging in its own frame. It's an all-in-one 
package that ensures the smoothest possible installation of your door. 
We recommend a prehung door if your situation is one of the following: 
1.  No existing door frame 
2.  The existing door frame is damaged 
3.  New construction 
Note:When installing an exterior door, unless you are a pro, it's extremely hard to tight-
fit an exterior slab door.  
·  Prehung doors come with weather-stripping and are tight-fitting off the shelf. 
·  A tight-fit door will save you on your energy bill. 
What to consider when buying a pre-hung door? 
·  Make sure the new door frame will fit the rough opening. We recommend a rough 
opening that is slightly larger than the outside unit dimension of the new prehung 
door. This allows for shimming to level the unit. 
·  Jamb width refers to the thickness of the wall. The jamb needs to cover the stud 
plus any wall application such as dry wall or sidings. 
·  Know your door handing (swing). Stand with your back against the hinge-side of 
the frame and extend an arm in the direction you wish the door to open. If you 
extended the left arm, then you need to order a LEFT-HANDED door. If you 
extended the right arm, then you need to order a RIGHT-HANDED door. 
·  Though exterior doors typically swing inward, outswinging exterior doors are 
available. So be sure to add "inswing" or "outswing" to your notes before 
ordering. 



