Timber Framers Guild Forums General General Forum Questions Importance of queen ties,braces in queen post barn

I am always a fan of the Dutch-English hybrid design that seemed to originate in the Northeast(especially in my Hudson valley area) "Queen post barn". There are lots of different variations on this barn design. I am wondering from an engineering perspective how important the queen tie is to the design? Additionally, how important the braces from queen post to tie are? Could you eliminate the braces and leave the tie or even eliminate both the tie and braces? It seems almost preferable to have stout standing braces(perhaps large enough to have some tensile capacity) from queen post to main girt below (near the brace connection from exterior post). In my mind the load is transferred from the rafters to the purlin plates to the queen posts and its purlin braces. The so called queen "ties" are not tying just adding rigidity and the brace purpose the same. For the purpose of floor plan, would you be able to eliminate the braces or the queen tie entirely and add standing braces to the main girt? Many barns did do this, but I wonder if it is a good idea to design with? I think its a hard question to answer. Perhaps someone has already done some engineering on queen post barn load tranfers ,and has come up with some insight. I cant be the only one who is attracted to these American-born barn designs. tb

If this is an H-frame supporting the roof then I would think that the "Tie" as you called it is in fact not a Tie as the roof load at that point will be pushing inward.
This is why, I'm sure, they made the "Canted Queen Post as it more appropriately opposes roof forces. Also with it's long brace, it transfers a the bulk of the outwardly forces directly into the Tie instead of into the plate. At least, that's the way I see it.

Thane

Youre right, it really isnt a tie, probably better named a straining beam,.
I do believe the canted queen post design to be superior, but in terms of human use, as a house frame or workshop space, the plumb queen post design is more aesthetically pleasing to many, allowing rooms or spaces to be framed by these support posts and their braces. Harder to do this with the canted posts . tb

Yes, I agree. It almost sounds as if you like it the way it is as well. I wouldn't change a thing. Just my $.02

Thane

In this case is is not just how you like it but more importantly does removing these members(braces or the whole beam) also remove the structural integrity? or is it just removing a bit of stiffness and rigidity that can be made up for in other areas? tb

Hi TB;

If I understand correctly, I think the brace or strut going into the purlin post may have been important during the raising, but unnecessary after the rafters were attached.

Jim

If I understand the question correctly, I believe many times these buildings rely on an upper ‘gable rafter set’, supported by the upper purlin plate, and a ‘lower shed rafter set’, supported by the upper and lower plates. In this case the upper tie beam, which is carrying the upper gable rafter set thrust or tension, is just that a tie beam and I believe a necessary element of the frame. I have built a number of building using an upper queen post/tie beam system and believe the tie beams are a required element. I’ve seen this style of building w/o the upper tie beam, but they will have common coller ties for the common rafters at the upper plate location. I also like the braces to the upper tie beam as they stiffen the roof system in the transverse direction.

Pete