Installation of Vinyl Posts on Concrete

Set the vinyl post on the concrete in the exact location where you want it installed. Trace the bottom of the post on the concrete with chalk or a mason's crayon. It may help you to have someone else hold the post straight in place while you trace.

Measure the width of the holes in the bottom of the post; there should be one near each corner. Then measure half that width in from each of the corners towards the center point of the post. For example, if the holes are 1 inch in diameter, measure ½ inch in from each of the four corners towards the center and make a mark with your chalk or crayon.

Drill into the concrete with a hammer drill and a 1 inch drill bit at each of your marked locations. Drill to a depth of at least 4 inches to ensure a firm foundation for the base of the vinyl post. Drill slowly; don't force the bit down, but allow it to gradually chew through the concrete. You will end up with four holes in your concrete.

Measure the distance from the base of your vinyl post to the center of your post, or to the spot of the middle rail in the fence, whichever is shorter. Add the depth of your hole (which is at least 4 inches) to that measurement. That is the length to which you must cut your rebar support system.

Cut your ½ inch or 3/8 inch rebar strips to the measurement you calculated. Set the spot at which you need to cut the rebar into a hydraulic bolt cutter and squeeze until it breaks through. Cut one rebar piece for each of the four holes.

Insert the rebar into each of the four holes and slide the vinyl post over top for a test fit. Make sure the post stands completely straight with all four rebar pieces inside. If not, tap the rebar until it stands straight up and try again. Continue until you have a straight up and down vinyl post. Remove the rebar and vinyl post.

Mix hydraulic cement and water in a bucket with a paddle mixer until it forms a consistency similar to pancake batter: thick but still pourable. Pour the cement into each of the holes until they are completely full. Immediately insert the rebar and top it with the vinyl post.

Use a level and a rubber mallet to make sure the post stands completely straight and sits completely flat against the concrete. Do this quickly, as the hydraulic cement sets up within 10 minutes and once it does, you will not be able to move the posts. Once the post is flush and plumb, it needs no other adjustments.