Calculating load for barn floor

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SUMMARY

The barn in question has been rated by an engineer to support 45 pounds per square foot (psf) at its weakest point. With a central bay designed for hatywagons and supported by three large tree trunks, the barn's capacity to hold a typical four-wheel wagon loaded with 6,500 pounds of hay is under scrutiny. The discussion highlights the importance of consulting an engineer regarding the load distribution from the wagon's tires, particularly given that the weight is concentrated on the rear axle. The consensus is that without proper engineering assessment, the safety of the structure cannot be guaranteed.

PREREQUISITES
  • Understanding of load-bearing capacity in structural engineering
  • Knowledge of pounds per square foot (psf) as a measurement unit
  • Familiarity with load distribution principles, particularly for wheeled vehicles
  • Basic understanding of barn construction and materials used
NEXT STEPS
  • Consult a structural engineer for load assessment and safety evaluation
  • Research load distribution calculations for wheeled vehicles on wooden structures
  • Investigate the structural integrity of barn beams and floor joists
  • Learn about tire pressure effects on load distribution in agricultural settings
USEFUL FOR

Farm owners, agricultural engineers, construction professionals, and anyone involved in assessing the structural safety of barns and similar buildings.

FCStorm
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TL;DR
Tractor weighs 6500 lbs. Floor is rated to 45 psf, with floor area of 390 feet. Safe to park tractor on floor?
I have a barn that with a central bay that was originally designed for supporting hatywagons, so it's undergirded by three huge tree trunks used as beams (running longitudinally, parallel to wheel tracks). It has previously been rated by an engineer as being capable of supporting 45 psf at its weakest point. The wagon bay is 390 sq2. Can the barn support a typical 4 wheel wagon loaded with conservatively 6500 pounds of hay? Assume the decking is up to the task: two layers of planking running at right angles and previously okayed by the engineer?
 
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Welcome to PF.

FCStorm said:
It has previously been rated by an engineer as being capable of supporting 45 psf at its weakest point.
What's psf? Pounds per square foot?

FCStorm said:
Can the barn support a typical 4 wheel wagon loaded with conservatively 6500 pounds of hay? Assume the decking is up to the task: two layers of planking running at right angles and previously okayed by the engineer?
Why aren't you asking the engineer this question?
 
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berkeman said:
Welcome to PF.


What's psf? Pounds per square foot?


Why aren't you asking the engineer this question?
He's no longer around.
 
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FCStorm said:
He's no longer around.
What did you do with him?!!

And why don't you go to the same agency to ask for a different engineer?
 
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berkeman said:
Why aren't you asking the engineer this question?
He was killed in a barn collapse.

Kidding aside, I don't see how we can answer this. The tractor sits on tires, so you have a few thousand pounds per square foot at the contact points. "Ah", you say "but the load is distributed through the floor and its bracing". Well, maybe so, but there is no way for us to calculate this.
 
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FCStorm said:
I have a barn that with a central bay that was originally designed for supporting hatywagons, so it's undergirded by three huge tree trunks used as beams (running longitudinally, parallel to wheel tracks).
6500 lbs, most of that weight is on the rear axle. Say 3000 lbs per rear wheel. Tire pressure will be about 18 psi, so tire contact area will be 3000/18 = 167 sq in, = 13" x 13" square of floor.

The supporting structure should be investigated to identify if it will safely support those two tire contact patches of 3000 pounds each.

I doubt it will be safe. How do you know that the tractor wheels will always be above the beams?

You must consult an engineer about the load-spreading nature of the floor boards, joists and beams.
 
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Baluncore said:
You must consult an engineer about the load-spreading nature of the floor boards, joists and beams.
Agreed. This thread is closed for safety reasons.
 
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