5 ms·

I knew someone who lived in the building, and while she didn't report cracks in the walls, she did say that things would reliably roll toward one corner of her

by whafro 8y ago

I knew someone who lived in the building, and while she didn't report cracks in the walls, she did say that things would reliably roll toward one corner of her apartment if they weren't secured.

tlb 8y ago
14 inches over 58 stories works out to 0.10 degrees. That doesn't seem like enough to make anything roll. You might have to shim your billiard table.
- kowdermeister 8y ago
  A golf ball sounds like something to me: https://www.youtube.com/watch?v=dCUCa0Bvh1k https://www.youtube.com/watch?v=dCUCa0Bvh1k
- saalweachter 8y ago
  Your floor being on a 0.1 degree slope is a rise of 0.2 inches over 10 feet. Definitely noticeable.
  - jessriedel 8y ago
    Not definitely. The professional standard for levelness in homes and office buildings is F_L ~ 20, where F_L is the levelness "F number". http://www.concretefloors.ca/?page_id=546 http://www.concretefloors.ca/?page_id=546 http://www.betagroupgc.com/Concrete%20International%20-%20The%20Floor%20Flatness%20Report.pdf http://www.betagroupgc.com/Concrete%20International%20-%20Th... The maximum slope b=rise/run compatible with this is b_max = (314 mm/3m)/F_L = .105/F_L ~ 0.005 for F_L = 20, https://www.astmfree.com/wp-content/uploads/2018/01/E-115-M.pdf https://www.astmfree.com/wp-content/uploads/2018/01/E-115-M.... which corresponds to 0.005 radians = 0.3 degrees. Projects like roller rinks and warehouses that use air pallets require more level floors, but typically only by a factor of 2 .
- greeneggs 8y ago
  Your math is wrong. The relevant angle is not 14 inches over 58 stories, it is 14 inches over the horizontal length of the building. I'm not sure what this. Guessing maybe 120 feet, e.g., gives a tilt of 180/pi * arctan(14/12/120) = 0.56 degrees.
  - yaakov34 8y ago
    Sorry, you are the one with the wrong math. The building is out 14 inches at the top. You divide that by the height to get the angle. What you calculated is the lean for a building which sank 14 inches on one side. That would be way worse - an excursion of [edit] 6 feet at the top.

by whafro 8y ago

I knew someone who lived in the building, and while she didn't report cracks in the walls, she did say that things would reliably roll toward one corner of her apartment if they weren't secured.

tlb 8y ago

14 inches over 58 stories works out to 0.10 degrees. That doesn't seem like enough to make anything roll. You might have to shim your billiard table.

kowdermeister 8y ago
A golf ball sounds like something to me: https://www.youtube.com/watch?v=dCUCa0Bvh1k https://www.youtube.com/watch?v=dCUCa0Bvh1k
saalweachter 8y ago
Your floor being on a 0.1 degree slope is a rise of 0.2 inches over 10 feet. Definitely noticeable.
- jessriedel 8y ago
  Not definitely. The professional standard for levelness in homes and office buildings is F_L ~ 20, where F_L is the levelness "F number". http://www.concretefloors.ca/?page_id=546 http://www.concretefloors.ca/?page_id=546 http://www.betagroupgc.com/Concrete%20International%20-%20The%20Floor%20Flatness%20Report.pdf http://www.betagroupgc.com/Concrete%20International%20-%20Th... The maximum slope b=rise/run compatible with this is b_max = (314 mm/3m)/F_L = .105/F_L ~ 0.005 for F_L = 20, https://www.astmfree.com/wp-content/uploads/2018/01/E-115-M.pdf https://www.astmfree.com/wp-content/uploads/2018/01/E-115-M.... which corresponds to 0.005 radians = 0.3 degrees. Projects like roller rinks and warehouses that use air pallets require more level floors, but typically only by a factor of 2 .
greeneggs 8y ago
Your math is wrong. The relevant angle is not 14 inches over 58 stories, it is 14 inches over the horizontal length of the building. I'm not sure what this. Guessing maybe 120 feet, e.g., gives a tilt of 180/pi * arctan(14/12/120) = 0.56 degrees.
- yaakov34 8y ago
  Sorry, you are the one with the wrong math. The building is out 14 inches at the top. You divide that by the height to get the angle. What you calculated is the lean for a building which sank 14 inches on one side. That would be way worse - an excursion of [edit] 6 feet at the top.