I have been working on a design alteration on a basic queen post barn frame. For clarity sake, the frame is one in which has tie below the plate: extended post of about 4 feet : continuous top plates; queen post bent with a a slight post extension to continuous purlin plates; common rafters tongue and forked; resting on purlin plates and then joined to the top plates. I think that covers it. I thought to perhaps add another tie from the queen post to the extended exterior post to help further stiffen the frame and alleviate the inherent weakness of such an extension. My thought was to add this perhaps only on the end bents and also that by adding this , I could possibly extend the post a bit more, to say 5 feet above the tie beam connection. The idea comes from looking at Dutch barn frames and seeing the "transverse strut" or tie beam from the main post to the side wall post. These usually occur just below the brace of the anchor beam and main post. The question is how to raise it or assemble it, as the Dutch raised their sidewalls into the H-frames and this is not possible in this frame, as it is not a sidewall but a extended post. I thought to perhaps use a lapped half dovetail , like is used for collar ties or braces. I also thought there might be a way to insert one end of the tie into its mortise and have the other mortise cut larger and slide the tenon in and then use a block to fill in the space of the remaining mortise , like seen in braces that have been added to already assembled framing. Any thoughts or ideas ? I have never seen this done, but that does not mean it is a bad idea. Has anyone else seen this before or have any ideas on how to join this ? thanks tb

I think you are referring to a "chase mortise".
Hewett talks about these in the book "historic english carpentry"
I've used this connection several times and always liked it.

One thought -- the end bents only have half the load and also often have the sheathing/wall helping tie things together. If you are going to reinforce the frame, a better place is the interior bents.

As long as the queens are supported sufficiently (post under them to the ground or very, very stiff tie beam that won't sag) you shouldn't have much need to add a tie at the top plate level.

But I course don't know the size of the frame or the spacing of bents or the roof pitch, so I could be off, here.

Thanks Mark and Gabel. Is it true that the end bents have only half the load of the interior bents? I always heard that the end bents carry the most stress. This idea came from looking at some Dutch barn frames where they would add another tie beam( on the end bents only) above the anchor beam at just below the top plate connection to help mitigate the roof thrust on the extended post tops. Also from Dutch house frames where they almost always had closely spaced bents with 3-4 foot extended posts for a kneewall 2nd story, but I have seen some of these frames where only on the end bents they used jowled posts and tying joint with an additional tiebeam. It is obvious why they could not put the additional tie beam on every bent as it would not allow for headroom, but I trust their reasoning that it could only help the frame on the end bents, where it would also not be in the way. I guess I am mistaken that the end bents are under more stress. Nonetheless I think these Dutch framers might have had a good idea when reinforcing the frame on its end bents. I am at the same time not ruling out the possibility to frame it in on the interior bents as well. Any ideas on framing this extra tie "strut" into this Queen post barn frame. I am seeing on paper that this tie "strut" might end up acting like a brace as in trusses, as it just about creates a triangle with the rafter. By the way the design was 3 bay, 4 bent , 30' wide by 40' long. 9/12 pitch.Bent spacing at 14-12-14. Just one interior tiebeam support in the middle at 15' o.c. Mostly 8" x 10" principal timber dimensions. Hope to hear more from you guys . tb

timber brained, if you have something on paper shoot a photo and post it so we can see clearly what you are proposing. I have seen a local barn with the end ties at plate level and the 2 interior bents dropped, not as much as you are planning though. Tim

The end bents do only have 1/2 the load (1/2 the tributary area). I believe most of the other horizontal members on the end bents are nailers for vertical siding. The Dutch barns are a little different in that the interior posts are continuous and therefore quite tall and perhaps need something tying them above the tie beam. You can still have discontinuous posts though and a strut or tie between the vertical purlin posts. I don't know about the ties between the outside posts and queen posts.

The queeen posts will resolve the rafter thrust (all? or some?), but you're going to want to calculate the forces on the post, as 4-5 ft is quite a bit of kneewall. And lastly you may want to put two interior posts close to the queen posts as opposed to one. It can be done with one, but you could have crazy point loading on the tie beam.

Sorry guys I have yet to learn how to post a picture, I dont have a scanner if that has anything to do with it. I did not want to change the tie beam level at the end bents so that I could allow for entry to possible add-on bent. Timberwrestler I dont think that the Dutch house frames I spoke of would have gone through the effort of cutting english tying joints and a framing in a whole other tie beam on the end bents just for nailers for vertical siding. Plus I think most Dutch frames used vertical studs and horizontal siding. With the Dutch barns I have seen, there is only ever an additional tie beam above the anchorbeam on the end bents, perhaps it would get in the way on the interior bents. It is good advice on adding another support post under the tie beams, your'e right that is a lot of accumulated load being transferred to those beams. As far as a tie between the queen posts, I dont see that it helps much as there is already a longitudinal tie member in the purlin plate and purlin braces. I still think this addition of horizontal tie girt from queen post to just below the exterior post top is worth consideration in possibly improving on this already successful, but not perfect American queen post barn. tb