Prehung vs. Slab DoorsIf you have a choice, buy the prehung door whenever possible. The door is already calibrated to fit the door frame perfectly. You wouldn’t believe how difficult it is to hang a slab door, unless you are replacing the doors on a one-for-one basis.
Price and Weight FactorsPrehung units are heavier that slab doors. After all, a slab door is just the door itself—nothing else. In the case of interior doors, slab doors can be very light-weight. But for exterior doors, slabs can be very heavy. Now imagine a prehung exterior door—slab plus all the surrounding framing. That is very heavy. Get help with moving the prehung units.
Prehung doors are more expensive than slab doors. This should be obvious, but it needs to be said. Even with both factors listed above—weight and expense—you’ll still probably find prehung doors a better bet than slabs.