Agreed Will.

I learned valuable lessons on my first frame for my father's screen porch that I cut in the summer of 2000. White oak for exterior use, and fresh as could be.

Nothing as dramatic or structural as you mention - but lots of little things where you can see into housings, or where a timber is now hanging on a peg in its joint...

In white pine I would never go less than 1" for something like this, but also make the decision based on loading, use, etc.

Thanks so much Tim, Mike, and Will for the very helpful responses.

I'm keen on Will's recommendation of using 1.5"x3" notches on two sides in an 8x10 (not 8x8) tiebeam, and then running as much of the joist as practical above the tie on the middle bent. I had been thinking about doing a pocket depth of 1.25" or 1.5", but extending it all the way thru the 8x10 tie as opposed to just 3"(see #2 in picture below). Will's recommendation (#1 in picture below) would remove less wood on the top side of the tie, and I would run 3" over the middle-bent tie. Im really liking that. It's clear a soffit tenon on one side would be stronger, but doing it this way keeps the location of both ties at the same height, and allows me the adzed reduction on both ends. Do I have to worry about the strength of the joist where the "notch" is made that transitions from the joist tenon to the 3" tail running over the tie?

[img]http://www.flickr.com/photos/danielcha/5483014336/sizes/l/[/img]

Thanks again guys.

It really depends on the intended load to be placed on the joists. Storing regular attic stuff is one thing, placing car engines up there is another....
You need to not only design for your plans but be aware of what future plans or storage will be put up there.

Cutting across the full width of the tie beam will mean that the cross section is reduced greatly and may need to be verified by running the numbers again to see if it will be ok for your load. Normally, I believe, they (engineers and code officials) don't like to see cuts completely across the top of the beams.

If you cut a 1.5" notch all the way across the beam then instead of an 8x10 you now have an 8x8-1/2 as far as the engineering goes. If this is in midspan of the beam it could be a problem. Basically the most correct way to model a beam's capacity is to recalculate the section modulus of the beam's cross section at the biggest notches. It's just a time consuming math problem, but it can have a significant impact on the strenght of the beam. I would recommend keeping those notches to 1.5 x 1.5, there really is no need to take the full 3" out, especially across the top. By doing so you have reduced have of the beams depth by 1-1/2".

Also, while I haven't run the numbers, intuitively 3" of carrying capacity for a 7" deep timber seems undersized. The "scoops" are dramatic and for some maybe aesthetically displeasing. While the 4-1/2" seems more practical. One way to look at this is to figure 3x5 gives you 15 square inches, just calculating for vertical shear in pine gives you 3x65 (going by memory here) for only 195 pounds of carrying capacity on one end, that's only 40 pounds per lineal foot, so with 4' spacing that gives you 10 psf, which is barely enough for dead load alone!...oops, that's right, I just looked it up, they bumped up shear for pine to 135 in the current NDS... so now you can add 10psf live load!