Introduction #
Exterior doors take more abuse than any other door in the house. They open and close constantly, face the weather, and shift a little as the house settles around them. A door that latched perfectly five years ago may now stick, drag, or leave gaps. Those gaps let in drafts, water, and bugs. The problem usually builds slowly, a little worse each season, until it is too big to ignore.
Common problems include the door not latching right, and gaps that let in air, water, or light. The door may also drag on the threshold, the flat piece at the bottom of the doorway that the door closes against. Weatherstripping, the seal strip around the door edge that blocks drafts, may stop touching the door all the way around. The deadbolt, a separate lock bolt above the doorknob, may stop sliding cleanly into the strike plate. The strike plate is the metal plate on the jamb, the door's frame, where the latch or bolt locks in. Any one of these problems hurts how well your home holds heat and stays secure. Left alone, they tend to get worse together: a sagging door creates gaps, and the gaps ruin weatherstrip contact. Bad contact then lets in water that can damage the threshold and the sill, the wood framing underneath it.
You can fix most of these problems with basic techniques. You rarely need to replace the whole door. There are three main adjustment points: the hinges, the strike plate, and the threshold. Once you understand those three, you can find and fix most exterior door problems fast. Find which point is causing the problem, make the fix, then check your work. Working through it in order saves time, and it keeps you from adjusting the wrong part and making the problem worse.
Before You Begin #
Prerequisites #
- Before you touch any hardware, pin down the exact problem: not latching, dragging, gaps, drafts, or the deadbolt not lining up.
- Make sure the door is accessible on both sides. You'll need to work from inside and outside while you check and adjust it.
What You Need To Know #
- Most exterior door problems come from one of three causes. Hinge settling: the door sags toward the latch side over time as screws loosen or pull out of soft framing. House settling: the door frame shifts as the structure moves. Seasonal wood movement: the door or frame expands and contracts as humidity and temperature change.
- Check plumb first. Plumb means perfectly vertical, and you check it by holding a level against the door. Checking plumb tells you where the problem is. Hold a 4-foot level against the latch side of the door when it's closed. If the top gap is bigger than the bottom gap on the latch side, the door is out of plumb at the top corner. That means a hinge problem: the top hinge has loosened and the door is sagging. If the door is out of plumb everywhere, the entire frame is racked, meaning twisted out of square. That points to a frame or structural problem that may need more involved repair.
- Always start with the simplest fix and work toward more complex ones. Replacing one hinge screw with a 3-inch screw takes 30 seconds and fixes most sagging door problems. Don't jump straight to re-mortising the strike plate (cutting a new pocket for it in a different spot) or replacing the weatherstrip. Confirm the door itself is hanging correctly first.
Tools Required #
Power Tools #
- Drill/driver
Hand Tools #
- Tape measure
- Screwdriver (Phillips and flat)
- 4-foot level
- Pencil
- Chisel
- Utility knife
- Flashlight (for checking gaps)
Supplies #
- 3" screws (for hinge repair - these reach through the jamb and into the structural framing behind it)
- Toothpicks and wood glue, or a hardwood dowel, a solid wood peg (for stripped screw holes)
- Cardboard shims (thin wedges you use to nudge a hinge or the door slightly)
- Weatherstrip adhesive
- Replacement weatherstripping (if needed)
How to Adjust an Exterior Door #
Step 1: Diagnose the Problem #
Close the door and look at all four sides carefully. Start by checking the gap between the door and the frame. It should be consistent all the way around, roughly 1/8 inch on the top and sides. Look for spots where the gap is wider or narrower than the rest. A wider gap at the top of the latch side, with a tighter gap at the bottom of the latch side, means the door is sagging. This is the most common exterior door problem, and it usually points to loose hinge screws at the top hinge.
Use a flashlight at night to check for light gaps. Have someone shine the flashlight from outside while you check from inside with the lights off. Light coming through around the door means there are gaps in the weatherstrip seal.
Check every area in order. Does the latch click fully into the strike plate? Does the deadbolt slide into the strike without forcing? Is the gap even on all four sides? Is the weatherstrip compressed evenly all the way around? And does the door bottom make contact with the sweep, the strip of vinyl or brush along the bottom that seals out drafts?
Pro Tip: The dollar bill test works well for checking weatherstripping. Close a dollar bill in the door at several points around the perimeter. If you can pull it out easily, the weatherstrip isn't making good contact at that spot. Test at least 8 points: top center, top corners, the middle of each side, bottom corners, and bottom center.
Step 2: Adjust Exterior Door Hinges to Fix Sagging #
If the door sags toward the latch side, the fix is usually simple. This is the most common exterior door problem. Replace the short screws in the top hinge with 3-inch screws that reach through the jamb and into the structural framing behind it. The factory screws that come with most hinges are only 3/4 inch long, so they only grip the jamb material itself. Over time, the weight of the door pulls these short screws loose, and the top of the door drops toward the latch side.
Open the door and support it from underneath (a book or shim under the bottom corner works). Remove one screw at a time from the top hinge on the jamb side and replace it with a 3-inch screw.
Drive the screw slowly. As it bites into the framing behind the jamb, it pulls the top of the jamb, and the door, back toward the hinge side. That closes the gap at the top of the latch side. Start with just the top hinge. Often, replacing one screw with a 3-inch screw is enough to bring the door back into alignment.
Pro Tip: Replacing one screw in the top hinge with a 3-inch screw fixes 80% of sagging exterior door problems. It is the single most effective fix you can make. It takes 30 seconds and needs only a drill/driver.
Step 3: Adjust the Strike Plate #
You may also need to adjust the strike plate. If the latch doesn't engage properly after you fix the hinge sag, the strike plate itself may need to move. Close the door slowly and watch where the latch contacts the strike plate. You'll see marks on the strike plate face showing where the latch is hitting. If the latch is hitting above or below the strike plate opening, the plate needs to move to match.
For minor misalignment, less than 1/8 inch, you can file the strike plate opening slightly larger with a metal file. This is the quickest fix and skips any mortise work. For bigger misalignment, remove the strike plate, fill the old screw holes with toothpicks and wood glue, let them dry, then re-mortise the strike plate in the correct position. You can also install an adjustable strike plate. These have a sliding tab that lets you fine-tune the latch engagement without moving the plate itself.
Step 4: Fix Gaps with Weatherstrip Adjustment #
After you fix the hinges and strike plate, check the weatherstripping. If it's compressed, torn, or not making full contact with the door face, you have two options: move the door closer to the weatherstrip, or replace the weatherstrip itself. Start by checking whether the weatherstrip is physically damaged. Look for sections that are flattened, cracked, hardened, or peeling away from the frame. Damaged weatherstrip needs to be replaced no matter where the door sits.
Most exterior door weatherstrip is kerf-mounted. It presses into a groove cut into the door frame, and a fin or barb on the back of the weatherstrip holds it in place.
To replace it, pull the old strip out of the kerf starting at one end. Clean the groove of any old adhesive or debris, then press the new strip into the groove. If the door has been adjusted and now sits farther from the frame on one side, you may need one more step to fix weatherstrip contact. Add a cardboard shim behind the hinge to push the door closer to the weatherstrip on the opposite side. This is called hinge shimming. You place a thin cardboard shim between the hinge leaf (the flat metal wing of the hinge) and the jamb mortise, the pocket that holds the hinge. That shifts the door's position slightly.
Step 5: Adjust the Threshold #
Modern exterior door thresholds have adjustment screws across the top surface that raise or lower the threshold height. These screws are usually hidden under small plastic caps that pop off with a flat screwdriver. Removing the caps exposes Phillips or slotted screws. Turning them clockwise raises the threshold, and counterclockwise lowers it. The goal is to raise the threshold until the door sweep or bottom seal makes light, even contact across the full width.
Don't over-tighten -- the door should still close without excessive force. If the threshold is too high, the door will drag and be hard to close, and the extra friction will wear out the door sweep prematurely. If it's too low, air, water, and insects will get through the gap at the bottom. Adjust all screws equally across the width of the threshold for a consistent seal. There are usually three to five adjustment screws evenly spaced -- turn each one the same amount to keep the threshold level.
Pro Tip: Threshold adjustment screws are typically under small plastic caps that pop off with a flat screwdriver. Turn clockwise to raise the threshold. Adjust all screws equally across the width for a consistent seal -- uneven adjustment creates gaps on one side while binding on the other.
Step 6: Fix Stripped Screw Holes #
If hinge screws spin freely and won't tighten, the screw holes are stripped. This is common in older exterior doors, where screws have been removed and re-driven many times. The wood fibers around the hole are crushed and can no longer grip the screw threads. Repair the holes before you try any hinge adjustment, or the fix won't hold.
For a quick fix, pack the hole with wooden toothpicks dipped in wood glue. Break the toothpicks off flush with the surface. Let the glue dry for at least an hour, then re-drive the screw. The toothpicks give the screw threads fresh wood fiber to grip.
For seriously damaged holes, where toothpicks aren't enough, drill out the hole to 3/8 inch. Glue in a hardwood dowel and let it dry overnight. Then drill a pilot hole, a small guide hole so the screw doesn't split the wood, through the dowel and drive the screw. This gives the screw solid wood to bite into, and it makes a permanent repair.
Quality Check: Verify Your Exterior Door Adjustment #
- The door latches without you forcing it.
- The deadbolt lines up and slides in smoothly.
- No light shows around the closed door.
- The weatherstrip touches the door on all four sides.
- The door swings freely without dragging.
- The threshold seals against the bottom of the door.
- The lock and handle work smoothly.
- The door stays where you leave it when open. It should not swing shut or open on its own.
Troubleshooting Exterior Door Adjustments #
Door Still Sags After Hinge Screw Replacement #
If the door still sags after you replace the top hinge screws with 3-inch screws, the problem may reach beyond a single hinge. Replace the screws in both the top and middle hinges with 3-inch screws. A heavy exterior door puts a lot of load on all its hinges, and the middle hinge may have loosened too. If the sag continues after you re-screw both hinges, the hinge mortise itself may be too deep. Place a thin cardboard shim behind the top hinge leaf, between the hinge and the jamb, to push the top of the door outward and correct the sag.
Deadbolt Won't Engage #
When the deadbolt won't slide into the strike plate, the frame has shifted enough that the bolt and the strike no longer line up. First, try the hinge screw fix from Step 2. Fixing a sagging door often brings the deadbolt back into alignment with its strike plate. If the deadbolt still misses the strike after that, you'll need to re-mortise the deadbolt strike plate in its new spot. Mark where the bolt actually hits the frame, remove the strike plate, extend the mortise to the new position with a chisel, and reinstall the plate.
Door Swings Open or Closed on Its Own #
A door that won't stay put when you open it means the frame is out of plumb. Gravity is pulling the door toward whichever side is lower. Shim behind the hinges to fix it. Add a cardboard shim behind the bottom hinge, between the hinge leaf and the jamb, to stop the door from swinging open on its own. Or add a shim behind the top hinge to stop it from swinging closed. The shim pushes the door slightly out of its mortise, which changes the angle it hangs at and counters the out-of-plumb frame.
Air Still Leaks After Weatherstrip Replacement #
If you still feel drafts after replacing the weatherstrip, check the door itself for warping. Hold a straightedge, a 4-foot level works well, against the face of the door on both sides. A warped door will show a gap between the straightedge and the door surface. A warped door can't keep even contact with weatherstrip all the way around. Minor warping, less than 1/4 inch, can sometimes be fixed with adjustable weatherstrip that has more compression range. Significant warping usually means the door slab itself needs to be replaced.
Threshold Leaks Water #
If water gets past the threshold even after you adjust it, one of two things is usually wrong. The threshold screws may not be raised high enough. Raise them until the door sweep makes firm contact. Or the exterior sealant joint between the threshold and the door sill may have failed. Check that joint on the outside of the threshold. If it looks cracked, peeling, or missing, water can get underneath the threshold and skip the top seal entirely. Resealing that joint is a painter or exterior-sealant crew job, not carpentry. Flag it instead of doing it yourself.
Helpful Resources #
These outside resources give more detail on specific parts of exterior door maintenance:
- U.S. Department of Energy - Weatherization Guide -- Covers weatherstripping standards and energy efficiency for doors and windows.
- Family Handyman - How to Fix a Sticking Door -- Detailed visual guide with additional techniques for stubborn door problems.
- This Old House - Door Repair Tips -- Expert advice on diagnosing and fixing common door alignment issues.
