Mortise Relish

[Rougespear]

I had a brief discussion with someone the other day about mortise relish at the end of a rafter plate where it joins the top of a post at the outside end of frame.  Conventional history here would recommend cutting the tenon on the top of the post back 2" from the reference face, and likewise reducing the size of the mortise correspondingly.  The guy made a very good case for eliminating the relish altogether: it's small and usually dries out so quickly that it checks and simply falls out anyways; it adds no strength to the joint design; and lastly, having no relish is an easier/quicker joint to cut.

Anyone have some thoughts on this take of the traditional mortise and tenon joint design?

[S.Hyland]

I really haven't had mine fall out, even when dry. I do anchor seal my end grain well so that may help. I like to have it there, even though it probably adds little strength. Personally, the open mortise would strike me as sloppy and would probably bother me.
I agree with the engineer that you are probably not loosing too much by eliminating it, from a practical standpoint though.