Building a privacy fence

[Alex Horvath]

Hi,

I'm building a privacy fence which consists of top and bottom 2x4 rail with 1"x8" vertical overlapping redwood fence boards.
I don't like to use the dadoed top and bottom rails because I see a fairly high fail rate given that they are weak. I'm also being a bit anal since my original builder redwood fence required regular, frustrating repairs beginning at 10 years and completely failed at 20 years in an arid climate.

So what I have done in the past is use pressure treated 2x4's for rails (no dado) and nail 3/4" x 1.5" cleats on both sides of the fence boards/rails to lock them in (essentially making a 1.5" deep dado).

I cut the cleats from premium pressure treated 2x6 doug fir.
This time I noticed that the pressure treatment only goes in a 1/8" or so from the edges.

I could go with redwood cleats but it seems that small pieces being so soft just don't last.
Perhaps I could hit the pressure treated cleats with a quality fence paint before install?
I'm using the brown PT 4x4 posts and rails so I'm not going to be color coordinated in any case and I won't be painting the fence.

Is there a big difference in above ground longevity between doug fir vs. redwood?
After all, the rafter tails and eaves on a house are painted doug fir and seem to last forever.

Thanks

[Eric Schmid]

I would use clear redwood for the nailing strips. It's going to look better. The fence boards are going to decay at the lower nailing strip first anyway. Wherever there is wood on wood is where the rot will begin. If you want to prolong the life of your fence it is best to avoid a dado at the bottom; whether pieced together or cut. This is usually impractical, however. The next best solution is to seal the wood on all sides before installation.

[Hoang N Nguyen]

Or you can just do composite material for the fence. They have them now where they look like wood but never needs paint or sealing and would last longer than you.