How to Anchor Posts for Railings to Concrete

Joining dissimilar materials, such as wood and concrete, requires specialized equipment and materials. Whenever wood is in contact with concrete, the concrete draws moisture out of the wood and causes dry rot. Anchor posts used to support railings that are fastened to concrete should be held above the concrete slightly so water drains away and the concrete does not cause the wood to deteriorate.

Things You'll Need

• Adjustable/standoff post base with slotted washer
• 1/2-inch anchor bolts and nuts
• Hammer drill
• 3/4-inch concrete drill bit
• Concrete epoxy
• 4-inch by 4-inch post
• Hammer
• 16d galvanized nails

Instructions

1. Mark the concrete where the post will be installed.

2. Drill a hole in the concrete where the center of the post will rest. The hole should be deep enough so the anchor bolt will extend above the concrete by 1 inch when it is fully inserted into the hole.

3. Fill the drilled hole with epoxy and push the anchor bolt into the hole. Wait for the epoxy to cure as specified by the epoxy manufacturer.

4. Set the post base over the anchor bolt with the bolt extending through the hole in the center of the base.

5. Put the slotted washer that came with the post base over the anchor bolt and tighten the nut on to the bolt.

6. Drop the supplied standoff plate into the center of the post base.

7. Set the post into the base, bend up the open side, and nail the post to the base using all available nail holes.

Tips & Warnings

• To quickly set up multiple posts, snap a chalk line parallel to the edge of the concrete and inset from the edge to the centers of the posts.

• Wear safety glasses when drilling and hammering. Follow manufacturer's warnings when using epoxy.

References

• Simpson Strong Tie Product Specifications for AB Post Base