timber frame free span

[jayzee]

  I want to build an indoor riding arena timber frame. I have a woodmizer that I can ( and have ) cut  40' material on. Is it possible to free span 60'  or should I just be satisfied with standard truss type construction ?  I plan on building the main building 60' x 120' with 16' eaves so I can come off each side with 20' shed roofs for hay , equipment storage , stalls, etc.  I have a friend here locally that has timber frame experience but we will need help.  Anyone out there want a summer timber frame job in the mountains of Northeastern Oregon ?  Check out Joseph on the internet . Cheers, Jayzee

[beenthere]

Anything is possible, but an engineer-design is best to span large areas (wasn't there a large timber span on the indoor stadium at Moscow, Idaho?).
Laminated lumber beams that are screwed, glued, nailed, and/or bolted can be built, of course depending on time, materials, skills, and money.
Then there was the Tacoma Stadium that was all-wood structure. Had the opportunity to walk through that structure over the top. Pretty awesome to look down at the basketball court from many feet in the air (don't recall now how many, but the basketball court looked like a small postage stamp way down there).
I believe Iowa State bulletins have truss designs and building designs that you might look into. Probably others as well. Might start at Oregon State college of engineering, and see what they have to offer. I think they have a structures engineering curiculum.
Wish you luck.

[Raphael]

Just got a small project in mind.  ;)

  60ft. is some span but not outside the realm of possibility.  What species do you have available in this length?  Is there going to be any floor load on the beams or are they just tying the frame and controlling the rafter thrust.
  Will the rafters need support from queen or king posts (if so you'll need to figure that into the load on the beams).  I guessing you get a little snow there...

[jayzee]

Thanks for the comments and suggestions. I plan on using western larch and douglas fir. Our fir here is much slower growing than the " west side " so stronger also. For instance , some  logs that  I recently cut  12x12's from averaged about  150 years old . My initial plan calls for a row of posts down each side on 15' centers . The roof from the main span will drop 5' and slope out to the second row of posts  20' out . I am thinking this shed roof structure surrounding the main building will strengthen it immensely. I can easily purchase prefab engineered trusses but that's no fun. I want to build a barn with the strength and character to be a local landmark 100 years from now. There isn't much timber framing and log construction in this area and the state inspector seems to favor lots of metal bracing and brackets so we may have to cheat a little with the truss construction and somehow hide some metal in them . Cheers, Jim.

[logwalker]

I refer to that as a buttress or flying buttress. Very old design. I used it in my shop/house design. In order for the sheds to reinforce the building you need to use half/jack trusses tied to their own foundation to stop lift. Very strong design. Do you have any pics or drawings? Joe

[Don P]

Just quickly winging it I came up with about 70,000 lbs thrust at the rafter to bottom chord joint. Yup, I'd say steel reinforcement and a good engineer    Don't skimp on grading either, this is a demanding design.

[Norwiscutter]

That would be quite a project.  I know a few people who might be interested in something similar.  Or at least until they saw the price tag.  For something like that, it would be best to consult an engineer before you get too involved.  That being said I think a riding arena such as that, would possibly open up new doors and opportunities down the road.  People with horses by their very nature tend to be people that don't mind spending money on fancy new Barns.  If you build one, I bet you could build 10 more that would more than justify the cost of your initial overhead.  My mom is considering building a riding arena in the next couple of years, so I am very interested in how your ideas shape up.

[jayzee]

I don't have any drawings or engineering yet . I wanted to throw this idea out to you guys to see if anyone had tackled a similar project . I really appreciate the feedback ! I am currently discussing this plan with the local log home builder , who coincidentally is my best customer. He recently built a barn with log trusses that free spanned 60 feet but had to incorporate steel plates . The logs were douglas fir , that he purchased from me , and were 12-14 inches diameter.  None of the steel reinforcement was visible when the job was complete. Impressive building! But not a timber frame . jimz@jayzeelumber.com