Japanese Joinery

The joinery I used is based on Japanese style joinery that is used even today.  Some of the joints will be familiar, but there are specific differences.  I started out by making a couple of trial pieces of all the major joints I'd be using.  That way I would know how each one is laid out, on the wood, and I wouldn't end up wasting a lot of wood.  The wood I chose was 2"x4"x8' building studs that I ripped down to 1 1/2"x1 1/2"x8" and 2"x1 1/2"x8'.  The 1 1/2"x1 1/2"x8' were used for the Roof Rafters, and the 2"x1 1/2"x8' were used for everything else.
The Post Top joints were the first joints I worked on, since they were the easiest joint to make (Picture 1 and 2).  Basically, it's a double tendon joint.  The bottom is rectangular in shape (and goes through the Rim Beam pieces) and the top is dovetail in shape (and holds the Roof rafters on top of the Rim Beam pieces).  The Posts, themselves, are 5'9" tall to the bottom of the tendon joint.  Pictures 3 and 4 show how they go together.  The cut out in Picture 3 is for a joint I will describe later.  The posts will also have 45° diagonal braces (two per post) that I will show later.  The posts for the four corners are done slightly different, they are just the upper portion of the joint, but it goes all the way to the shoulder of the joint (Picture 1a and 2a) The next joint I worked on was the Rim Beams Scarf joints (Pictures 5, 6, and 7).  It's a lap joint with an added step to it (the "step" being the raised parts that form the hole in the middle of the joint).  I rounded the hole in the middle of the joint with a 1/2" drill bit, so that it would accept a 1/2" oak dowel peg.  Once the peg is installed, the joint is as strong as an uncut piece of wood.  The Rim Beam ended up with two joints on the long sides, each, and one joint on the short ends, each.  Pictures 7a, b, and c show Rim joints with pins installed.  When the pins are installed, it is a good idea to soak them in water first so that they will swell and make the joint tighter and stronger.
				Rim Joint
Next I worked on the Rim Beams Corner joints (Pictures 8, 9, 10, 11, 12).  There is a corner joint for each of the four corners.  After that I worked on the Ridge Beam joints (Pictures 13 and 14) and there are two joints along the length of the beam.  The next step was to build the Middle Spanner Beam, which spans the middle of the frame; mainly to help keep the frame square and to add a little overall strength the the entire frame.  The beam was built using a couple of pieces of ripped 2x4 that ended up bowing, a little, so that the beam is actually arched in shape.  The beam also helps to hold up the middle section of the Ridge Beam.  Pictures 15, 16, and 17 show the Middle Spanner Beam and its joints.
Corner Joint, Male	Corner Joint, Female
The Rafters were the next part I worked on.