Mortise Sharing

[Brian_Weekley]

In trying to maximize the width of a door opening, I was planning to house two adjacent tenons in a single mortise (a brace and door stud).  As the two separate timbers dry in a single mortise, I imagine the fit might be a little worse down the road compared to single tenons in their own dedicated mortises.  In this case, I don't see this as being a critical joint anyway.  However, just wondering if there is any precedence for this in traditional joinery?  Is it acceptable or discouraged?



 

[Dave Shepard]

I've seen shared mortises before. I would think after shrinkage of the stud the peg would be carrying the load. I think there are pics of shared joinery in Jack's HATJ.

[AMB30518]

I was wondering the same thing but my braces are on opposite sides of my post, with the tenon ends butting eachother.

[Brian_Weekley]

Thanks, Dave.  Wouldn't all brace joints end up putting some load on the pegs if the post were to shrink?  I guess what I'm doing is really no different than a brace with a packing piece, eh?

[Jim_Rogers]

I was wondering the same thing but my braces are on opposite sides of my post, with the tenon ends butting eachother.

Tenon ends should never butt each other trim to allow for shrinkage.

[Jim_Rogers]

Thanks, Dave.  Wouldn't all brace joints end up putting some load on the pegs if the post were to shrink?  I guess what I'm doing is really no different than a brace with a packing piece, eh?

If the peg holes are draw bored then there should be come spring in the peg to help hold the brace into the post.
When draw boring braces you have to draw it in two directions, in and down against the bearing end of the tenon. This hopefully will keep the bearing end and the shoulder against the post.

Brian, your top tenon and stud pocket will work but you should draw bore your stud tenon against the bearing end of the brace tenon. That way there will be pressure against the bearing end of the tenon.

Jim Rogers

[witterbound]

Does your door stud really need a big ole tenon to hold it in?   

[Jim_Rogers]

There are alternative methods.

If it is the hinge side then maybe it might.
But if it's the latch side or if it's a sliding door maybe not.

Here is one from my gallery of cutting joints.



Basically you toe nail the bevel at the top into the beam.
The bottom is cut with a standard stub tenon and then the top is cut with a bevel and matching bevel in the beam. After the frame is raised you tilt it into place, by putting the stub tenon into the sill beam and then pivot it up to the tie beam/plate or whatever beam that is.

I just wanted you to know that there are other ways to do the same thing. Then the siding will help hold it in.

Jim Rogers