When your building’s connections are not plumb or fail to maintain a proper roof pitch, erectors can insert a shim to adjust the connection. Even though many erectors don’t use shims, there is a proper technique to this adjustment and, at times, a very real need for its use.
Here’s what you must know about the shim technique.
Erectors often bolt pieces together without any evaluation of the building’s allowable deflections. When they do, the result can be a frame that is deflecting lower than the adjacent frame. It may be a purely aesthetic issue or it may be a concern for proper clearances required for hangar doors or special equipment inside the building.
Using shims can create proper alignment and roof pitch when done correctly. And, yes, there is a proper technique to using a shim. The use of “fillers” as referenced by the AISC (American Institute of Steel Construction) up to 1/4″ is acceptable and Star will provide instructions upon request on how to perform the proper shim, as well as the shims needed.
Generally, 90% of buildings will bolt up just fine. However, in the 10% where there is an issue, erectors need to recognize there is a problem and contact us about the situation so we can provide guidance on techniques for shimming.
There’s my quick fix! Do you have questions? Comments? Want more details? Send me a comment below. And stay tuned for more quick fixes to keep your job on schedule, on budget, and on the move.