This is the gate at the side of our house. Although it is hung on two 4 x 4 posts (left side of the photo) and both have concrete footers, both began to lean a tiny amount toward the right side of the photo. That made the latch string hard to pull and the gate rubbed against the plate on the side of the house.

If the 4 x 4 posts appear to lean to the left, that is only an illusion of perspective because of the camera angle. There was a large bush at my left elbow and I could not move farther to the left when I took the photo.

I did a search on Instructables and could not find anything similar to what I am showing here. Although my solution is very simple and may be obvious to many, this could be of help to someone who does not happen to think of it. Although this Instructable may not be as glamorous as preparing for a Zombie Apocalypse, there comes a time when all of us will deal with home repairs, and this is a common one.

Step 1: What Needs to Be Done

My wife wanted me simply to trim the gate at the side near the house. That would solve the problem for a short while, but in time the sagging would continue and the gate would need to be trimmed again. After a while, the vertical lines would no longer be parallel. And, the parts of the latch would no longer align. The parts of the latch would need to be re-aligned.

The tops of the two 4 x 4 posts need to be pulled away from the house slightly. The simple way to do that is to add a strut that will pull so as to shorten the red line I have laid over the photo.

I used a rule to measure the length of the red line and I used an angle finder to determine the angle of the red line relative to the vertical lines.

The photo shows the outside or street view of the gate. I do not want to add a strut to this side, but to the inside of the fence. I also showed the outside of the gate because I am writing this Instructable after I made and installed the strut.

Materials

1/8 x 3/4 x 4 inches strap iron
1/8 x 1 x 3 inches strap iron
3/8 inch concrete reinforcement bar
1 inch angle iron
5/16 inch threaded rod
2 nuts 5/16 inch
1 lag bolt 5/16 x 2 1/2 inches
3 lag bolts 1/4 x 1 1/2 inches
paint

Tools

Hacksaw or angle grinder with a cutting wheel and a grinding wheel
Rule
Angle finder
Drill and bits
Welder
Wrenches for installing lag bolts and for making adjustments
Spring clamps

Step 2: The Strut in Place

This photo was taken from behind the gate, not from the street side. The strut I made is steel. There is welding. It also has two nuts on a threaded portion that makes it completely adjustable. Later I will mention a way this problem could be solved without welding. See the next steps for construction details.

Step 3: Threaded Rod

I welded some 5/16 inch threaded rod to the end of a piece of 3/8 inch concrete reinforcement bar. I made a wedge point on the end of the reinforcement bar for a more complete weld. After welding, I cut the threaded rod extension to the reinforcement bar to about 2 inches in length and filed the end so a nut can be placed onto the threads easily.

Step 4: The Adjustment

The red line in step 1 is about 65 inches long. The reinforcement bar is in two pieces, each about 30 inches long. Add the length of the threaded rod and the two flat pieces that will anchor the strut on both ends, and the total length of the strut is 65 inches.

I used an "L"-shaped piece of angle iron for part of the adjustment. The threaded rod passes through a hole in the angle and the adjustment is set with two nuts. The angle is welded to the other piece of reinforcement bar. I probably used heavier, thicker steel than was necessary, but I was not certain how much tension would be needed to pull the 4 x 4 posts back into alignment.

Step 5: The Bottom Mounting Plate

The bottom mounting plate is a piece of 1/8 inch strap iron 3/4 inch wide and about 4 inches long. The welded section has an inch or so of overlap for a good strong bead. I used three holes with three 1/4 inch lag bolts each 1 1/2 inches long. Because of the way the fence is constructed, very little of the 4 x 4 post is available for mounting the plate. That is why I used multiple lag bolts.

Step 6: The Top Mounting Plate

I used 1/8 inch strap iron 1 inch wide. The top mounting bolt is a 5/16 inch lag bolt 2 1/2 inches long.

Step 7: Installation

Paint the strut. I rubbed the parts down with lacquer thinner to remove oils. I used gray primer followed by black enamel.

I bolted the two sections of the strut together at the adjustment. I left most of the threaded portion available above the angle so I could tighten the adjustment as much as I want later. Then I mounted the top of the strut. Next I mounted the bottom of the strut. Then I tightened the adjustment until the two parts of the latch aligned for smooth operation.

No welder? The cheapest possible way to pull two posts to one side so the gate hangs straight would be to pound a large nail into the posts at the top and bottom of the line the strut defines. Run at least two plies of fairly heavy steel wire between the nails. Use a flat paddle, like a paint stirrer, to twist and hold the twist in the wire.