After 17 years, a gate post that a contractor had installed into a slab had finally rotted, and I was left pondering a solution.

First I rocked the post and broke through the last of the unrotted wood. Discovering that all the rot was below the surface, I was able to trim it off and use the original post.

Rotted gate post

Backyard DIY fix a rotted gate post

First I used a 1 ¼” auger with an extender and drilled out as much of the old wood as I could. With the help of a 6' wrecking bar and a pry bar, I was able to break up and auger out the existing wood down to about 14”.

Next, I used a 2” spade bit with the same extension piece to drill into the bottom of the post 6”. 

1 1/4" auger spade to fix rotted gate.

I glued a 1 ½” outside dimension 12” nipple using Gorilla Glue into the post. I then added a connector piece to lengthen it and give the concrete something extra to hang onto. 


I let the glue dry overnight, then I inserted the pipe into the hole and attached it to my sawhorse in order to hold it level. So that I wouldn’t have to worry about the height, I added enough gravel so that when the pipe rested on the gravel, the bottom of the post was ½" above the concrete. This method should protect it from rotting in the future. (I took this into account when I trimmed the post.)

Before I mixed the cement, I made sure all my tools were in place and laid down cardboard to protect the existing concrete. I leaned the post to the side so that I could get the concrete into the hole easily, knowing that I could re-level it to my sawhorse while it was loose.

Carefully following the Rapid Set cement directions, I mixed the cement and filled the hole just about to the top. I then leaned the post the other way and found that I needed more concrete.

Clamp gate post into concrete.

Once it was close to the top of the hole again, I leveled the post, carefully pushed the remaining concrete into the hole, and smoothed it with a trowel. I followed the recommendation to mist the surface of the curing concrete so that it wouldn’t crack as it cured.

Fixed: DIY rotted gate post.

Lastly, I let the cement sit overnight, reattached the hardware, and rehung the gate. 

DIY how to fix rotted fence post.

Looking for more solutions for rotting wood? Check out how to prevent rot and decay and how to use epoxy for rot repair.