I've got a 24' x 40' tractor barn built just after the turn of the 20th century. It's a combination timber frame/ stick frame, but here's the weird part: there's no ridgepole, but there are two sets of pseudo-rafters that come up toward the ridge from either side of several of the floor beams (they're not attached to the roof). They meet at a simple 2x8 "ridgepole" that's a few feet below the ridge. Through this ridgepole are fastened two iron rods that dive straight down through the two beams, and there's a large washer and nut on the underside of the beams.

I know little about framing, and am probably not describing this well (I could post a picture or two), but I've never seen this before. It seems original to the structure.

Anyone see this design before, and was it just to keep the floor from sagging?

Thanks!

Let's see the photos

Photos of the barn in question: http://depts.husson.edu/caseyk/barn/

Any help in putting a name to this strategy (principal rafters that meet at a flying ridgepole with vertical iron rods that tie to the beam below) would be appreciated.

Could you post photos of the "floor beam" to post conection and the rod to floor beam conection?

From what I could see, and how it's described, it seems to be some sort of truss to hold up the floor.
Maybe?

It looks like the simplest of King Post trusses. The rod is acting in tension holding the floor beam up at close to mid span and directing the load to the exterior wall timbers. I haven't seen it used like that before but it sure is a simple solution.

was the cieling(second floor) ever used to hold up weight?
like an engine hoist? you would probably see marks from the fasteners even if the system is gone....

Interesting. The designer clearly knew better than to hang the king rod from rafters that weren't attached to the tie beam. This scheme allowed him to drop the tie beam. Perhaps to increase the loft space? CB.

Additional barn images up at http://depts.husson.edu/caseyk/barn/

No doubt, from looking through the pictures, that is a simple king "post" truss to support the floor. Doesn't appear to have anything to do with supporting the roof.

So cool.

Joe

I agree that the only purpose served by the rod is to suspend the floor framing
However the bottom "chords" of the truss' are resolving most of the outward thrust of the roof (those collar ties are way up there)
The location of the floor beam down on the post below the plate means there is a lot of thrust on the post/beam conection
And it looks as tho some repair has been done with steel at the post plate conection.
Interesting...a little spooky...but interesting

I have the same arrangement in my 1905 barn, although the top of the truss is only waist high and spans 32' and runs parallel to the ridge line. Was originally a hayloft. There is no post down below on the main floor and is very stout.

Even though I am a little late with my two cents but here they are anyway.

This is nothing else but a king post truss were the "king post" is a metal rod thus allowing for a long clear span on the first floor with no obstructions like posts. It does nothing for the roof and does not need to. The rod is on tension with the floor practically hanging on it. The braces are on compression and transfer the load to the exterior walls near the post. The tie beam is therefore also under tension. They might have use a rod instead of a post because it is less intrusive. Reminds me of a german build roof systems.
So the only thing different compared to what one finds in most other barns is the fact that tha truss is seperated from the roof/rafter. Not so unusual after all.

I recently evaluated a barn in Pennsylvania which had multiple additions and modifications. One of the additions had a very similar "King Rod" arrangement, not attached to the roof system. It was obviously in place to allow the clear span below which happened to be open to the exterior as it was a dairy barn and the cows came in under this part of the addition. It was a bit unconventional from my limited experience, but it seemed a very logical and simple solution. If I can find a photo, I'll post it.