I built this fence on top of an existing block wall that was too low to provide the privacy we wanted. The fence is made of treated pine and the posts are 3x15s.
The wall was made of hollow blocks and the fence was built on top of it. I filled the blocks with concrete and rebar to provide a solid foundation for the fence. This made the fence much more stable and secure, and also strengthened the wall. I placed expansion screws in the wet concrete with the post base, and then I tightened them when the concrete was dry.
I wanted to add some nice detail to the posts, so I added some crown molding to the base and the top of each post. I added a chamfer to the edges to give it a nice finished look.
The horizontal boards were cut long enough to span 3 posts, and were placed like masonry bricks to to strengthen the fence.
- I didn't account for the boards shrinking and expanding. I should have left a little more space in the molding and between the horizontal boards since wood expands perpendicular to the grain. This caused the molding at the top of the posts to detach.
- I should have sanded the boards to help the paint stick better. Wood tends to seal over time, and the paint didn't stick well to the boards that were milled a long time ago. Slightly sanding the boards with 120 grit sand paper would have helped the paint stick better.