How to reinforce exterior and sliding doors
To reinforce a door, replace the short screws in each strike plate and hinge with 3-inch wood screws that reach the wall framing, and check the deadbolt throws at least 1 inch. On sliding doors, add a pin or key lock and put screws in the overhead track so the door can't be lifted out.
Strike plate screws and hardware to buy
Police in Independence, Missouri, say most doors give way at the jamb, not at the lock. The thin wood around a door is the weak link. The Lee County Sheriff's Office in Florida says standard installs use short #9 wood screws that offer very little support against a hard blow.
For each exterior door, the sheriff's office says to plan on 11 fully threaded, 3-inch wood screws: two for the strike plate and nine for three hinges. They reach through the jamb into the framing. It estimates this triples the resistance of a solid-core exterior door. That's an estimate, not a test result, and your result will depend on the door and frame.
Also check these. The first three come from the Irvine Police Department's checklist:
- A solid-core front door
- A deadbolt with at least a 1-inch throw
- A strike plate held by at least two 3-inch screws
- A heavier four-screw or box strike, if your current plate is thin
- For sliding doors, a pin-type or keyed lock, plus screws for the overhead track
Which doors to do and how to secure a sliding door
Do every door to the outside: front, back, side and any door between the garage and the house. Burglars generally give up quickly. The National Crime Prevention Institute figure, cited by Independence police, is that a burglar will spend no more than 60 seconds trying to get in. The aim is to outlast that minute.
At the strike plate, the long screws go through the plate and jamb into the stud beside the door. At each hinge, swap the screws on the jamb side. The door side doesn't need 3-inch screws, and they'd come through the door's face.
For a sliding door, Independence police say a pin-type or key lock beats a broomstick or bar in the track. Two or three screws in the overhead track help stop the door being lifted out. Leave just enough clearance for the door to slide. A dowel can still add a backup layer, as Irvine police suggest for sliding windows, but everyone at home must be able to pull it out fast in a fire.
If you have glass or a mail drop within 40 inches of the door, Irvine police suggest a double-cylinder deadbolt, with a key always kept nearby. This type needs a key to open from inside, which can slow an escape in a fire. Some local codes restrict it, so check with your building or fire department first.
How to reinforce a door, one step at a time
- Check the existing screws
Take out one strike plate screw and look at its length. Short ones stop in the jamb.
- Fit the strike plate
Replace the strike plate screws one at a time with 3-inch screws, or install a heavier plate. Drill pilot holes first.
- Upgrade the hinges
Replace the jamb-side hinge screws one by one, so the door stays hung.
- Test the deadbolt
Close the door and throw the bolt. It should extend at least 1 inch without binding. If it drags, the screws may have pulled the jamb, so back them off slightly.
- Secure the sliding door
Add a pin-type or keyed lock. Then drive two or three screws into the overhead track, and test that the door still slides.
- Check the frame
If the jamb is split, rotted or loose from the wall, call a carpenter or locksmith before you add hardware.
What it costs to reinforce a door frame
| Item | What it costs | Notes |
|---|---|---|
| 3-inch wood screws | Varies; low cost | Plan on 11 per door |
| Heavy-duty strike plate | Varies by design | Optional upgrade over the original plate |
| Sliding door pin or keyed lock | Varies by model | One per door |
| New deadbolt | Varies by grade | About one hour's work, says the Lee County sheriff |
| Frame repair | Varies; get a quote | Needed if the jamb is split or rotted |
How to reinforce a door without these mistakes
- Driving screws without a pilot hole, which can split the jamb.
- Overtightening hinge screws until the jamb bows and the door binds. Snug is enough.
- Stopping at the strike plate and leaving the hinges with short screws.
- Trusting the latch a sliding door came with. Add a pin-type or keyed lock.
- Blocking an escape route. Anything you add must come off fast from inside.
What homeowners say about door strike plate upgrades
Do this the same day you change the locks, while the drill is out. Owners in two threads say to pull one strike-plate screw to see how short it is. Replace it with a 2.5–3 inch screw so it bites into the stud, not just the thin door jamb. (Reddit)
Door strike plate and sliding door questions
How long should strike plate screws be?
Three inches. Irvine police call for at least two 3-inch screws, so they pass through the jamb into the framing.
How do I stop a sliding door from being lifted out?
Independence police suggest two or three screws in the overhead track. Leave enough clearance for the door to slide, and pair this with a pin-type or keyed lock.
Is a broomstick in the track enough for a sliding door?
It's better than nothing, but Independence police say a pin-type or key lock is better than a broomstick or bar. If you use one, make sure anyone at home can remove it quickly.
What you’ll need
Sources: sheriffleefl.org, irvinepd.gov, independencemo.gov
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.