Hello all,
I’m a rookie timber framer working on my first project, the restoration/ stabilization of a 200 year old 3 bay stone bank barn. I’d like to thank you all in advance for any help you can provide.
My current dilemma is the design of a post (8”x8”x20’ nominal) with the intersection of three beams, 8” nominal width. I am currently planning on using housed mortise and tenon joints with a 1” shoulder and a 2” wide x 4” deep tenon. With three of them intersecting at the same place on the post I’m concerned that I’ll have removed too much material from the post (more than 50%).

So, I’m open to suggestions. Do I need to enlarge the post to a 10”x10”? Should I be using a different set of joints?

Thank you all in advance,

rick

My first suggestion is to make sure that there is no other way to arrange your timbers so that they don't all take a bite out of your post at the same elevation. Next, verify the loads going into the post to verify the depth of your housing, relish on the tennons etc. Check to see if you have any material left in your post. Upsize the post as required. I would use a low through spline on your opposing timbers, especially if you have any tension and a high tenon on the third timber. It will be fun getting all these tenons into place in an existing building. Good Luck!