Hi folks,

I am an experienced carpenter, but no timber framing experience. I have a project that is calling for antique hand-hewn timbers to frame in 2 garage door openings- 4 posts for legs and 1 continous header. Since the design shows the header running past the two outside posts, all I am coming up with is just 4 mortise and tenon joints pegged. I would greatly appreciate any input/ideas.

Several questions seem to jump out. How is the timber structure tied to the rest of the building ? How much load will they carry beyond their own weight ? Leads to the question size - many single garage door openings have 2x8 or 2x10 laminated headers suppored by laminated posts of 2/8's sitting on footers of big sill plates. How far apart with the two inner posts be ? You may want to offset these mortise / tenon joints so they do not align along the long axis of the header. Recess or pocket the bottom of the header to sit on the post tops and reduce the walking. Will the header be long enough outside the outer posts to accomodate a brace to prevent racking in the door wall ?
Just a few of the questions leading to a design which an engineer can bless before you build.
work safe, have fun

Thanks for your reply Emmett,

My plan is to do the joinery on the ground and raise it like a bent, I can't see another way of doing it. The rest of the framing in the garage is standard dimensional lumber. There is about 2 ft between the center posts and 3 ft on each end for bracing. My main concerns are getting the joinery right, and securing the bottom of the posts. I'm thinking that I'll have to mount a pressure treated block to the bottom of each post so that it's not sitting directly on the concrete.

JD,
Progress is a challenge you seem to be meeting.
The grounding of posts in a garage is fraught with two problems. One is bumping into them with the vehicles. A very secure fastening is called for. The second is water, The bottom of the post wicking up water is a fast route to failure. You can lick both devils with a metal pan post bottom which is secured to the concrete and to the post. If it sits slightly off the floor so much the better. There are commercial post bottom pans available or you can fabricate your own. A strap up from the pan on the unseen side of the post is easily lag screwed to the post. The pan can be gunned to the concrete or use a jbolt when you pour. By all means slobber the post end with sealer and use a sheet (cut to size) of ice dam rubber between the post and the pan. Moisture gone forever.
It sounds like the header extensions beyond the outside posts lend themselves to braces back to the posts. A 2.5 foot long brace made of stock half the cross section of the post (or slightly smaller) & header should work fine. Cut the tenons on the end of the braces to insert into the header/posts at right angles even though the tenon will be triangular in basic shape. Inlet the mortices about 1/2" so the brace goes in first is is very secure. A Single peg for insurance after the structure is up.
There many technques to attach the stick frame to the post and beam elements. Many old barns cut shallow open mortices on the face of posts/beams to let the stick framing pass by and become part of the structure.
Again, by all means get an engineer to bless the plan before you cut stick one.
work safe, have fun
deralte