How to fix a sagging metal fence gate

After enough time, a sagging gate on your property is inevitable. Battered by wind, rain, and snow and scorched by the sun on a daily basis, gates bear the brunt of the elements and begin to sag.

A sagging gate makes your yard look tired and unattractive. Worse, a sagging gate will not close properly—a hazard for children and pets.

The good thing is that sagging wood gates can be fixed easily and inexpensively. You'll first tighten up the hinges or replace them. If that doesn't do it, you can attach an anti-sag kit—guaranteed to fix the sag.

Your wood gate may be sagging for two reasons: the gate's hinges are no longer tight or the gate itself has sagged out of square.

With repeated opening and closing, the screws that hold the hinges to the posts begin to loosen. You can tighten up the screws or add longer screws that do a better job of grabbing into the wood.

Gate hinges are strong but sometimes they can bend, especially under extreme weight. In some cases, the gate hinges may rust or bend. Replacing the hinges will fix this problem.

The gate must form a nearly perfect square or rectangle to fit in its gate opening. Enough openings and closings will cause this square or rectangle to distort into a parallelogram.

Tightening screws does help, but often it is not enough. An inexpensive anti-sag gate kit is exactly what you need to force that parallelogram back into a proper square or rectangle. 

Anti-sag kits consist of two corner braces, four cable clamps, and a metal turnbuckle, along with a stranded steel cable and fasteners. These kits work for gates up to 6 feet high and 4 feet wide.

Whether the gate is shaped as a square or a rectangle, square is still the proper term for either gate when all four angles of the shape are at 90 degrees (or a perfect L-shape).

It's best to fix your sagging gate in dry weather. Wet wood expands, making it more difficult to calculate the right size and shape of the gate. 

  • Anti-sag gate kit
  • Replacement gate hinges
  • Replacement gate screws

  1. If the gate hinges are twisted, bent, or rusted, replace them with new hinges. Unscrew the hinges from the post and remove the gate. Unscrew the old hinges from the gate and replace them with the new hinges.

  2. If you are keeping the existing hinges, use the cordless drill to tighten all of the screws that attach the hinges to the gate and to the post.

  3. If any of the screws rotate with very little pressure applied when you are tightening them, this means that they are no longer properly holding. Remove the screw, measure its length, then purchase screws of the same diameter but 1/2 inch longer. Replace any faulty screws with these longer screws.

  4. Use the tape measure to determine whether the gate is square. Measure the diagonal in one direction, then measure diagonal in the other direction. If the two measurements do not match, the gate is out of square. It can be squared up with an anti-sag kit.

    Work on the gate on the inside; that is, the side where the support pieces are visible.

  5. Most gates that are out of square will sag downward from the hinges. The brace should start at the top hinge and continue diagonally down the gate to its lower right corner.

  6. Position the two corner braces with one at the upper left corner and one at the lower right corner. Drill pilot holes. Add the screws to attach the braces.

  7. Screw out the turnbuckle until it is fully extended. Attach it to the lower brace.

    A turnbuckle is a metal tensioning device with two threaded bolts that draw together when turned with a wrench.

  8. Insert the steel cable through the turnbuckle and through the lower right brace.

  9. Pull the cable tight by hand. Bolt two of the cable clamps at one end of the cable, then bolt the second pair of cable clamps to the other end.

  10. Use the wrench to turn the turnbuckle, further tightening it. As you tighten, the sag should disappear, with the gate becoming level again. Open and close the gate to test.