OP
Beltzington
Platinum Member
Odd, I thought I was standing on a cantilever every time I walk down the aisle of an airborne commercial airliner.
Calculating Cantilever Load Limits - Rule of Thumb?
- Thread starter Beltzington
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Odd, I thought I was standing on a cantilever every time I walk down the aisle of an airborne commercial airliner.
Streetcar
Veteran Member
Most sidewalks on truss bridges are cantilever
CalG
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Calculations could be made IF the fastener positions were known.
If there is but ONE fastener with a 700# Shear capacity, it can hold ZERO load cantilevered, the load will spin.
Think of a lever, the load, the fulcrum, and resistance. the spacing between the fulcrum and the other two points is the solution to the entire problem. (even if the fasteners are arrange vertically).
If there is but ONE fastener with a 700# Shear capacity, it can hold ZERO load cantilevered, the load will spin.
Think of a lever, the load, the fulcrum, and resistance. the spacing between the fulcrum and the other two points is the solution to the entire problem. (even if the fasteners are arrange vertically).
s219
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Don't rely on the fasteners or wood grain just in upper cantilevered boards -- run additional brace boards on a 45 (or steeper) from the end of the cantilevered boards and back down to the structure. Will make a huge difference. I do that, just with 2x4 lumber and 20D nails holding things together, and have never run into issues.
LD1
Epic Contributor
Sad degree you have there.
Look at alot of houses like split levels that have a little cantilever to the upper rooms. Or roof overhangs. Many many decks have cantilever.
OP
Beltzington
Platinum Member
Good stuff!
This thread confirms my theory, simple minds over-simplify things and complex minds over-complicate things. True genius lies in finding the middle ground.
CalG - You are correct and good evaluation with limited information. One bolt would create a nice seesaw not scaffolding.
S219 - Your picture is almost exactly like my setup with the exception of the angled supports, I was going with a second board bolted directly under the extension but I believe your method would provide more stability even if the load bearing isn't a consideration. Taking the roofing out today and if it is not 100+ degrees I may do some testing.
Good discussion even if we all don't agree on the solution.
OP
Beltzington
Platinum Member
Here you are ladies, empirical evidence
250lbs suspended 28" from the fulcrum. Placed marks on the siding and no movement or snap-crackle-pop for over an hour. Granted this is a static load but considering the weight will be suspended between two points I do not see this failing. So what do the naysayers have to say? If the best you have, is you can never be too safe, please crawl back into your bomb shelter and await a safer world. The rest of us acknowledge living is not a risk free endeavor.
250lbs suspended 28" from the fulcrum. Placed marks on the siding and no movement or snap-crackle-pop for over an hour. Granted this is a static load but considering the weight will be suspended between two points I do not see this failing. So what do the naysayers have to say? If the best you have, is you can never be too safe, please crawl back into your bomb shelter and await a safer world. The rest of us acknowledge living is not a risk free endeavor.
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LD1
Epic Contributor
I think you are just fine.
That's just a temporary platform for doing roofing correct?
If so, I'd probably just stand in my loader bucket and be done.
That's just a temporary platform for doing roofing correct?
If so, I'd probably just stand in my loader bucket and be done.