Question
Mark:

Good afternoon!

I'm working on the design for a fence...and I've almost made up my mind.  The kicker is what size fence posts to use.  My choices are an 8x8 cedar post or a 6x6 cedar post.  Obviously, the 6x6 is cheaper and, personally, I think it will look aesthetically more pleasing next to the 6x6 posts that are on my pergola over the back porch.

My question.  I plan on mortising, in the middle (actually, offset slightly to allow for the pickets), for the 2x4 runners.  Let me throw some measurements at you:

Mortise in 2" on each side (maybe only 1.75").  This leaves either 2 or 2.5 inches in the middle from one direction.  I'll mortise in  1 7/8" from the rear and 2 5/8" from the front (my picket size is a full 3/4").  Thus, at three spots on my 6 foot cedar post I will have about a 2x2" "weak spot".  

What do you think?  Is that structurally sound?  If not, I could go with the 8x8; however, I'd much prefer the 6x6.

Thanks for any advice you may have!  I mainly just want your honest opinion :).  FYI - I'm also an expert on Allexperts...Microsoft Excel forum.

Answer
Hello,

By allowing 1-3/4 inch for each 2 by 4 rail you will have a total of 2-1/2 inches of free space in which to adjust the location of the rails. I would just locate the rails through the center of the 6 by 6 posts if the offset you mentioned is not critical to the design. A 6 by 6 post can accomodate two 2 by 4 rails without any loss of strength. Offsetting the location of the rails should not be a problem.

You have chosen a good way to construct a fence and you have chosen a good material,cedar,which is highly resistant to rot and is produced naturally. The mortise method of course requires no fasteners and is actually stronger than other connection methods. Good luck. I will check out your post on all experts.

Mark Harshman


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