From 
Image 1 of 18
The sandwich post design we show features long-lasting treated wood below grade and attractive rough-sawn cedar above. If cedar isn’t available at your lumberyard, you can substitute any other wood for the above-grade materials or build the entire screen out of treated wood. All framing materials, treated and untreated, will last longer and look better if you stain everything, especially the cut ends.
Image 2 of 18
1. Clamp the four 2x4 rails
together and mark the post and picket positions. Cut off the
remaining ends 6 in. beyond the last post.
Image 3 of 18
2. Cut the
45-degree bevels on both ends. Flip over the rails and cut a series of 1-1/2
in. deep saw kerfs at the post locations, then break out the wood and flatten
the bottoms with a chisel.
Image 4 of 18
3. Position the privacy panel
postholes by laying a rail on the ground and driving two stakes behind it. Then
drive stakes 2 in. away from the centers of the post notches to mark the
postholes.
Image 5 of 18
4. Dig 8-in. diameter, 3-ft.
deep postholes. Reposition the rail over the holes, then screw the rail to the
positioning stakes and pour 6 in. of gravel into each hole.
Image 6 of 18
5. Pre-assemble the 2x6 and 2x4
treated post bases and set them in the holes, nesting them into the rail
notches. Plumb each post and temporarily screw them to the guide
rail.
Image 7 of 18
6. Pour dry concrete into each
hole until it’s 3 in. below grade. Mark and cut the 2x6s about 3 in.
above grade.
Image 8 of 18
7. Screw the cedar 2x6s to one
side of the 2x4s, then level and screw the two back rails in place using Figure
A for the height details. Plumb and brace the posts in both
directions.
Image 9 of 18
8. Cut the 2x2 picket top caps
to length and screw them to the 2x6 posts. Then push the pickets against the
top cap and screw them to both rails using your layout marks as a
guide.
Image 10 of 18
9. Attach the front cedar 2x6
posts using the precut notches in the front top rail as a guide. Secure them
with 3-in. screws every 6 in.
Image 11 of 18
10. Attach temporary blocks on
each end post and prop up a long 1x4 on a 16-in. block halfway between them.
Mark the post heights.
Image 12 of 18
11. Transfer the lines to the
other side and cut off the posts from each side. Finish the 2x4 center cut with
a handsaw.
Image 13 of 18
12. Cut the corners on the 1x8
top cap board, center it and screw it to the tops of the posts. Repeat the
steps with the 1x6 and 1x4 caps using Figure A for the
lengths.
