How to Build a Wood Board-on-Board Fence

Objective: To build the most popular style of wood fence that offers privacy and is aesthetically pleasing.

Equipment: Hammer, compressor, air hose, pry bar, tape measure, torpedo level, string line, circular saw, sixteen penny rail nails, six penny picket nails, loose six penny nails, 12’ piece of plastic conduit, nail guns, nail gun oil, circular saw and a pry bar.

Key Topics:

  1. How to install the rails
  2. How to install the pickets
  3. How to build a board-on-board fence

How to install the rails 

The height that the rails are installed at depends on the style of the fence. Simply determine the style of your wood fence and you will then be able to find out where the rails need to be installed. In most cases, the bottom rail is installed 7-8” above the grade, the top rail is installed 7-8” from the top of the fence, and the middle rail is installed evenly between the top and bottom rails. Make sure that you do not place your rails any closer to the top or bottom of the fence than indicated. Cedar is less likely to twist or bow than pine or treated wood, it will still bow if it isn’t held firmly in place.

Drawing of a 6' cedar solid privacy fence
Diagram of rail positioning on post for a wood fence

Once the concrete has hardened around your wooden posts (though not a moment sooner), you are ready to install the rails on your wood fence. The steps below are generic enough to apply to all wood fencing, but there are differences with different wood types that will be discussed later.

1. Lay your rails out three per section for a 6’ fence and two per bay for 4’ fence.

2. With a crayon, indicate on your post where the top of each rail will need to be.

3. To begin, ensure that your posts are set at 7’ 10” center to center, then start installing your rails at one end of the fence. Set the first rail flush to the edge of the post. You will want to install your rails so they are on the outside of your yard, facing your neighbor’s or the public’s side. This might seem like a stylistic choice, but many strict building codes require that the “good” side of the wood fence be facing out.

4. As the rail extends to the next post, cut the rail at the center of the post. You will need to repeat this for all three rails. Then, start with another rail butted firmly against the installed rail. Again, cut the rail at the center of the next post. The rails should always be joined at the center of the post. Use your circular saw to cut the rails. Be sure that the depth is set correctly, avoiding cutting into the post.

5. Install two sixteen penny nails where the rail covers the post, one at each end of the rail. Make sure that you do not get too close to the end of the rail or next to a knot to avoid splitting the wood.

Drawing demonstrating how wood fence rails should look after installation

6. Follow all the above steps and repeat throughout the fence line. When finished, the rails should flow with the grade.

How to install the pickets

The pickets will be installed on the neighbor/public side of the fence, leaving the good side facing outward. 

1. Layout enough pickets at each section, standing the pickets up against the fence.

2. At each change in grade or elevation, temporarily nail one picket. Do not worry about properly spacing these pickets. You will remove these temporary pickets and fit them into the fence line once you start to install all the pickets.

3. Place a six penny nail half way into the top of each temporary picket.

Drawing of a wood fence with rails and temporary pickets installed

4. Run a string line from temporary picket to temporary picket, wrapping the string around each nail as shown below.

5. The string line represents the top of the fence and how it flows. Evaluate the string line to determine if you can make any adjustments in the fence line to make it “flow” better. You may slightly push a picket into the ground and you may raise a picket a couple inches above grade. Too much variation will lead to a large gap at the bottom of the fence.

6. After making your adjustments, start at one end of the fence line. Place your first picket flush to the end of the rails or the edge of the house.

7. Each picket will receive two six penny nails at each rail. Nail the picket to the rail with one nail at the top rail.

8. Before proceeding to add more nails, place your torpedo level alongside of the picket and level it.

9. Refer to the information below on how to space your pickets for a board-on-board fence. Once you have achieved your board on board spacing, come back to this section, starting with step 10 below.

Finished privacy wood fence on uneven ground
Diagram demonstrating how nails should be evenly spaced with each other and the edge of the picket

10. Move any temporary pickets once you reach them during installation to ensure the spacing is consistent but the string line also stays intact.

11. As you begin installation, only use two nails per picket. Once you reach the end of the run, you can go back and add the remaining nails. This way, if you make a mistake or pickets aren’t lining up properly, it will not be as apparent at the end of the run.

12. Make sure the nails and picket are in the center of the rail and about an inch from the side of the picket during installation. This is an important step to reduce the chance of splitting the picket or rail. Your finished project should have nails installed in a straight line, not scattered up and down.

13. The head of each nail should be slightly countersunk into the picket to ensure that it does not come out over time.

How to build a board-on-board fence

Board-on-board fences have a 3 ½” spacing between the pickets. Board-on-board pickets are also on both sides of the fence. Spaces between pickets alternate on both sides in such a way that there is no visible gap in the fence.

1. On the public side (otherwise known as the outside) of the fence, place a picket on each post to cover the post and rail connections.

2. Evenly space out the pickets, leaving room for about 3-1/2” of space between pickets. Start with the outside pickets and then move on to the inside.

3. One the homeowner (otherwise known as the inside) of the fence, place your first picket centered in the first section of the fence. Then install the balance of pickets between posts using identical spacing as the outside of the fence.

© 2018 The American Fence Company. All rights reserved. Permission granted to reproduce for personal and educational use only. Commercial use, copying or distribution is prohibited without express written permission from The American Fence Company.

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