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Erection tolerance for steel structure

Erection tolerance for steel structure

Erection tolerance for steel structure

(OP)
Does anyone know what he tolerance is for out of plane rolling of a PEMB rafter?
I have a rafter that is apx. 48" deep, span of about 115' that has rolled out of plane
about 7/8" or around 1 degree, and I can't find any allowable tolerances for such a thing.

RE: Erection tolerance for steel structure

What matters is that it is straight in the in place condition. These things are skinny, and must be braced sufficiently to keep them aligned.

RE: Erection tolerance for steel structure

(OP)
It is erected and in place, but it's rolled out of plane 7/8". It is braced
like any other PEMB rafter, but I am concerned about the roll.

RE: Erection tolerance for steel structure

Are the roof purlins continuous or simple span?
If they are continuous, how long are the laps over the rafter?
How many bolts are in the lap and how many bolts connect the lap to the rafter?
Are there any reinforcing clips at the purlin to rafter connection?
Are the angle braces from the purlin to the bottom flange/web of the rafter on both sides or just one side?
Are the angle braces at every purlin, every other purlin or are they spaced further apart than every other purlin?
Have you had the building manufacturer review the condition with pictures or a site visit?
Is the roof panel standing seam or screw-down ribbed roof panel or something else?
All of these members should be plumb or at least normal to the plane of the roof panel.
Are the owners/managers admitting to heavy snow falls, high wind loads or over-filling grain storage buildings, etc., etc.???

There are more questions but pictures with scaling objects or rulers would help.

Jim,

RE: Erection tolerance for steel structure

My apologies. I thought the member was crooked along its length, rather than out of plumb. If you can't bring it back into plumb with the connecting purlins and bracing, you need more bracing.

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