Pole Barn Truss Raising
Pole Barn Truss Raising
(OP)
I am in the process of building a pole barn, and am considering different methods of raising the roof. I have seen a pole barn roof constructed on ground level, then winched into place.
I didn't actually see this done, but drove by on my way to work and the truss/purlins etc were all framed up around the poles on ground level. I saw a boat winch hanging from every gable pole. When I came home from work the whole thing was in the air.
This would seem to have some advantages. The option of raising trusses individually requires getting them back in plumb then tying them together with purlins while 20' in the air. I am thinking about getting some help and am worried about someone falling.
Problem: I havent been able to find anything about this method of construction - pitfalls etc. Any input?
I didn't actually see this done, but drove by on my way to work and the truss/purlins etc were all framed up around the poles on ground level. I saw a boat winch hanging from every gable pole. When I came home from work the whole thing was in the air.
This would seem to have some advantages. The option of raising trusses individually requires getting them back in plumb then tying them together with purlins while 20' in the air. I am thinking about getting some help and am worried about someone falling.
Problem: I havent been able to find anything about this method of construction - pitfalls etc. Any input?






RE: Pole Barn Truss Raising
Also refer to R. Buckminster Fuller, Geodesic Domes, Temcor Inc., Spruce Goose Long Beach 1982, etc. for some different configurations of this "build down" technique.
www.northeastaquastore.com re. geodesic dome construction.
Rod
PS---If your ever in the Los Angeles area you might stop in at the Powell Library on the UCLA campus and check out the huge collection of photos during the construction of the campus in the 1920's/1930's. A real eye opener!
RE: Pole Barn Truss Raising
I am wondering why you think this would be more time intensive.
I can see the added cost of building some sort of rigging for the post tops and the winches/chain hoists. This would be somewhat offset by the cost to rent a fork lift.
I once rigged up a fairly large superstructure with hydraulic cylinders and raised it the 6" necessary... sort of like set of camper jacks. It worked pretty well, this seemed like a similar problem.
Interesting link you sent, I may opt for the more conventional approach. Sometimes convention is driven by experience.
RE: Pole Barn Truss Raising
Some months ago a Contractor I am connected with did the same thing; but in reverse. Built a concrete basement slab over the harbour and lowered it into the water to provide a below water level carpark. Required many jacks and checks during lowering.
Also it has been standard practice here and New Zealand to build timber portal frames on the ground and lift the roof as a whole with cranes in one go (but generally not wth the roofing on).
Jim