How to Install an Exterior Door?

Replacing your exterior door is one of the best ways to upgrade your home’s curb appeal, energy efficiency, and security. This step-by-step guide covers everything from removal to sealing. Inspired By Doors has a stunning selection to make your next door replacement effortless.

How to Remove the Old Exterior Door?

Start by taking the door off its hinges, then remove all trim, screws, and nails attaching the frame to the rough opening. Use a utility knife to score any caulk around the casing. Carefully pry off the interior and exterior trim using a flat bar, trying not to damage surrounding materials. Once the door slab is out, use a reciprocating saw to cut through nails or screws securing the old frame. Gently work the jamb free from the wall. Don’t forget to remove any shims, insulation, or foam left behind. Cleaning out the opening now will make installing your new unit much smoother — and ensure a tight, secure fit.

How to Check and Prepare the Rough Opening?

A level, dry, and structurally sound rough opening is essential for a successful exterior door installation. Start by measuring the height and width of the opening and compare it to your new door unit’s dimensions. Check for squareness using a framing square — all four corners should be 90 degrees. Test for plumb and level with a spirit level on the sides and sill. If the bottom framing is damaged or uneven, fix it with shims or replace the subfloor section. Clear out any debris and old caulk. A clean, level base makes sure the sill won’t flex and that your door opens and closes smoothly.

How to Install the Sill and Place the Door Unit?

A properly installed sill prevents water intrusion and supports the entire door frame. Lay a thick bead of waterproof caulk or sill pan along the bottom of the rough opening. Place the sill in position and double-check its level front to back and side to side. If not, adjust using shims under the sill until it’s perfectly stable. Once the sill is ready, gently lift the door unit into the opening — always from the outside. Center it in the space and let it rest on the prepared base. This sets the stage for aligning the frame and securing the unit without forcing or twisting it.

How to Shim and Secure the Door Frame?

Shims create the support needed to keep your door plumb and square during installation. Start on the hinge side — insert shims behind each hinge location between the frame and rough opening, checking with a level as you go. Make sure the reveal (gap) around the door is even. Once aligned, secure the frame by driving screws through the hinge-side jamb and into the shims. Repeat the process on the latch side and top, adjusting as needed. Don’t over-tighten or you could twist the frame. After everything is square and snug, trim excess shims and prepare for hardware installation.

How to Install the Hinges and Lockset?

Properly installed hardware keeps your exterior door secure, weather-tight, and easy to use. If you’re installing a prehung door, the hinges are usually factory-mounted. Confirm all screws are tight and replace any short screws with longer ones that go into the framing for added strength. For slab doors, mark and chisel hinge mortises carefully before attaching. Install the latch and strike plates so the door closes flush without gaps. Check that the deadbolt and knob are aligned and smooth to operate. Misaligned hardware can create drafts and shorten the life of your lockset — test everything before finalizing.

How to Seal and Weatherproof the Exterior Door?

A well-sealed door keeps moisture out and comfort in — protecting your home from the elements year-round. Apply low-expansion foam between the frame and the wall cavity, focusing on gaps that could leak air or water. Once the foam cures, trim the excess and install interior and exterior casing. On the outside, use silicone caulk around the trim edges, especially at the top and corners. Add or replace weatherstripping along the top and sides of the door frame. Make sure the door sweep at the bottom seals tightly against the threshold without dragging. These finishing touches ensure efficiency and longevity.