scarf joint location

jtbartlett · April 01, 2011, 09:48:51 PM

I am starting to draw up plans for a 24 X 40 shed style frame. The longer axis will make scarf joints necessary on the back eave girt, the upper ridge beam and the front eave girt. I am constrained to 18' timbers (length of sawmill bed) so I'm having a bit of trouble placing the scarf joints over support. Is it acceptable to put a tenon through a scarf joint? I believe I'll need to locate at least 1 scarf joint directly over a post. The bays are 14', 12', 14' and the beams are 10X12. https://forestryforum.com/gallery/displayimage.php?&pos=-95964

jtbartlett · April 02, 2011, 08:46:25 AM

Or, I guess I should have asked if it's ok to put a tenon through a splayed scarf joint, or is it better to use a bladed scarf? I'm pretty green about timber framing but slowly catchinh up.

witterbound · April 02, 2011, 09:02:30 AM

Seems to me that there is a difference of opinion on where to put a scarf joint. Some think over a post, and others think over a brace.

jtbartlett · April 02, 2011, 09:45:07 AM

Right, I'm having the problem of having 2 scarf joints in a 40' span. I have great examples of a bladed scarf with a through tenon into a sill, but have not seen an example of one in a girt. I'll look around some more, it's probably as common as green grass but it's all brand new to me. Thanks.

Jim_Rogers · April 03, 2011, 06:49:34 AM

First of all there are some rules to sizing scarfs.

One that Jack Sobon likes to use is the length of the scarf has to be 4 times the depth of the beam. So a 8x8 needs a 32" long scarf.

In the past I have used 3 times the depth of the beam, but will bow to the expert, and suggest four.

It is not best to put a scarf over a post.

Do what you need to do to move them and make it work, but remember that you will be taking the risk if you don't follow the industry standard.

More later on this when I have the time to post.

Jim

jtbartlett · April 03, 2011, 01:30:27 PM

Thanks Witterbound and Jim. Here are my plans so far. They are not done. I am using Google Sketchup to draw them. I am trying no eliminate a 'floating' joint (for lack of a better term) by placing them over the inside posts.