Step-by-Step Instructions

Swapping out an exterior unit demands patience and an assistant. A solid pre-hung unit easily weighs well over one hundred pounds, making solo installation dangerous and highly frustrating.

Phase One: Removal and Waterproofing

Put on your safety glasses and carefully score the caulking around the exterior trim with a utility knife to prevent paint damage. Pry off the exterior and interior trim. Remove the hinge pins to detach the old slab, then cut through the old nails securing the jamb to the framing using your reciprocating saw. Pull the old frame out of the rough opening. Inspect the subfloor beneath the threshold for rot; you must replace any compromised wood before proceeding. Apply a layer of self-adhesive flashing tape over the sill to create a waterproof barrier that protects your framing from future moisture damage.

Phase Two: Setting the New Unit

Run three thick continuous beads of exterior silicone caulk along the sill where the new threshold will sit. With your assistant, tilt the new pre-hung unit into the rough opening, resting the bottom on the caulked sill first. Press it firmly into place. Have your assistant hold the unit steady while you grab your four-foot level. Place the level on the hinge-side jamb. Insert wooden shims between the jamb and the framing until the hinge side reads perfectly plumb.

Phase Three: Securing and Insulating

Drive a three-inch exterior screw through the top hinge, driving it through the shim and deep into the wall stud. Repeat this process for the middle and bottom hinges. Move to the latch side, shimming it so the gap between the door slab and the weatherstripping remains uniform from top to bottom. Secure the latch side with screws driven through the jamb and shims. Test the swing; the slab should open smoothly and stay in place without drifting open or closed. Once satisfied, carefully fill the gap between the jamb and the rough framing with minimal expanding foam insulation. Do not overfill the cavity, as excess foam pressure can bow the jambs and ruin the smooth operation.