Wood Privacy Fence
I was minding my own business one day when my next door neighbour approached me about a privacy fence he was thinking about building across the bottom of his yard. He proposed continuing the fence along the bottom of my yard as well. At first I was hesitant, but once I saw the uncommon design he was considering, I was intrigued. Since I am always looking for a new challenge, I agreed to join him in the venture.
The Design
My neighbour was responsible for the design of the fence. He based it on one that he found in a book, with a few modifications in the interest of economy. The key elements are outlined below:
Dadoed Posts
The posts were milled with dadoes to accept the fence boards. We used a router with a 5/8 inch straight bit (I recommend using a spiral bit for this sort of milling) with the final depth set at 1/2" (Hind sight being 20/20, we should have gone a bit deeper to allow for more movement. After three years, I had to replace a number of boards that popped out of the dadoes because the posts had twisted slightly).
We attached 1x2 runners to the bottom of the router to act as guides and we milled the dadoes slightly wider than the 5/8 inch required for the boards to allow for some movement.
Protecting the Posts
The dadoes were treated with end-cut preservative. The bottom three feet of each post was coated with creosote to help protect the posts once they were in the ground. We set the posts in 3 foot deep holes with crushed stone at the bottom to allow for drainage. The posts were anchored in place using concrete. We used 1x2 boards tacked to the posts and tacked to stakes to hold the posts in place until the concrete set up. 2x2's or even 2x3's would have been better.
**Concrete will shorten the life of the fence. Wood expands and contracts, cement does not. The wood fibers will become crushed and the posts will weaken and rot prematurely because of this. For a longer life, the fence posts should be anchored in place using pea gravel, which will drain water away from the post, permit the wood to expand and contract without crushing it, and allow for easy replacement of posts that do become damaged.
The Bottom Rails
We used 2x4s for the bottom rails. The rails are positioned horizontally and were originally fastened to the posts using 3 inch screws toe-nailed from the sides and top. After 3 years, a couple of these rails needed replacing because of damage from the screws. Now the top and bottom rails are fastened to the posts using fence brackets for a stronger connection.
The Fence Boards
The fence boards were cut slightly longer than the depth of the dado. We used 1 1/2 inch finishing nails nailed head first into the edge of each board (3 per board) to act as dowels to pin the boards together. The theory here was that warping would be minimized and any warping that would take place would be in the same direction. Using wood dowels or milling tongue and groove edges would have accomplished the same thing. But the nails were quick and easy and after 3 years, seemed to be doing their job. We double checked the measurements of the fence boards every third course or so and adjusted our cuts to compensate for posts being ever-so-slightly off-vertical. There is very little room for error with this design. All cuts were protected with end-cut preservative.
The Top Rails
The top rails were fastened in the same manner as the bottom rails by toe-nailing them to the posts using 3 inch deck screws. Three years later, fence brackets were installed for a better connection.