A prehung door is a door slab already mounted within its own frame and jamb, complete with hinges installed and often pre-drilled for lock hardware, sold and installed as a complete, ready-to-use unit rather than requiring separate assembly of individual components on site.
This complete assembly significantly simplifies installation compared to building a frame and hanging a door slab separately, since the manufacturer has already ensured proper alignment and operation before the unit ever reaches the job site.
Prehung doors are available in both exterior and interior configurations, with exterior versions often including integrated weatherstripping and sometimes a threshold, further simplifying the installation of a complete, properly weatherproofed door assembly.
What Does a Prehung Door Involve?
- A door slab mounted within its frame and jamb
- Hinges already installed and aligned
- Often pre-drilled lock hardware locations
- Integrated weatherstripping in exterior versions
Why Are Prehung Doors Important?
The complete, factory-assembled nature of a prehung door significantly simplifies installation and helps ensure proper alignment and operation, reducing the risk of the fitting and adjustment issues that assembling a frame and slab separately on site might introduce. This convenience and reliability has made prehung doors the standard choice for most new construction and full door replacement projects.
Because a prehung door replaces the entire frame assembly rather than just the slab, this approach is the appropriate choice when the existing frame is damaged, poorly installed, or when a size or style change beyond what a simple slab swap could achieve is desired. This reliability is a major reason prehung units remain the default choice for most door projects today.
Prehung Door vs. Slab Door
A prehung door includes the complete frame assembly, ready for installation into a rough opening. A slab door is just the door panel itself, intended for installation into an existing frame that remains in place and in good condition.