Thanks for the informative replies everybody.
An over and under tenon looks interesting,although at this stage I don't have the confidence in my woodwoorking skills to start considering more complicated joints.I'd prefer to keep the joints as simple as possible - as long as my dimensions allow for pinning.As for the timber dimensions (105mm x 105mm),these are the standard dimensions for posts in the part of the world where I live (Japan),and since our house will only have a light,low-pitched tin roof I feel no need to increase the beam dimensions.Things here are generally done on a smaller and finer scale than in the West,something that it's taken me a while to get used to.
Likewise the pin shape here is usually square,which probably reflects the fact that yesteryear's builders had no access to powerdrills - and neither will I.I'll be doing everything with hand tools,with no access to a power source.
The alignment of the square tenons with the ones on the other side of the beam is a point to consider,although I'm a little stumped by the meaning of the terms "square rule" and "layout"......?
Also the shrinkage of the posts and consequent exposure of the mortise shoulders is something to consider.I wonder if it would be worth shortening the blind tenons a little - although that would of course exacerbate my problem with the pins,which remains my main concern.
In case anyone is wondering why I'm asking these questions on this forum,when I live in a land that contains the oldest and most intricate wooden structures in the world - well,it's partly a matter of limited language skills on my part (this is not a simple subject),as well as the cultural difficulty of obtaining a direct,to-the-point answer in this part of the world.But most importantly it comes down to the fact that pure timber framing is a dying art here,and it is very difficult to find one of the few remaining old men whose craft it is,or was.
Regards
Iain Andrews
