How to Install Fence Posts in Rock

One of the most frustrating and challenging aspects of building a fence is encountering solid rock. Fence lines often need to be run over areas of pure rock, for instance, when putting up stock fence in rural areas. Posts, whether wooden or T-posts, can be set in solid rock. It is a hard job that is best done with two workers. The result is a fence line supported by solid posts.

Tall tree trunk with peeling bark
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Step 1

Measure out the fence line and mark on the rock where each post is to go. At each mark, use a rock drill to cut a series of holes in a circle and inside the circle. Drill holes to create a circle twice the diameter of the post and 6 to 10 inches deep.

Step 2

With a medium-size bit, use the jack hammer to break all the rock out from inside the drilled circle. Scoop all the rock fragments out of the hole. Repeat the drilling pattern down another 6 to 10 inches. Break this up with the jack hammer and clean out the hole.

Step 3

Continue drilling and hammering out the rock until the hole is 2 feet deep. Set the wooden post in the hole with the fence-post level locked onto an upper corner of the post.

Step 4

Mix a sack of the cement in the wheelbarrow. Hold the post in position and check it with a level. Have an assistant shovel cement into the hole around the fence post. Fill the hole, then add extra cement at the base of the post. Use the shovel to sculpt the cement to make a rise around the post; this will keep water from pooling up around the post.

Step 5

Brace the post perfectly level as the cement sets.

Step 6

Set steel T-posts in rock by drilling a hole slightly larger in diameter than the T-post. Knock the spade off the bottom of the T-post. Drop the bottom end of the post in the hole. If it is snug, tap the post down with a hammer. If it is loose, fill in around the post with cement.

Step 7

Allow 24 hours for the cement to fully harden before stretching wire and attaching it to the posts.