Portal framed shed - bracing bolts becoming loose

[jonse]

Writing this to poll anybody's experience of the bolts at the wind bracing connections (both vertical bracing and plan /roof bracing) becoming loose.

I have a client that owns a number of portal framed "shed" type buildings used for retail purposes. Three of these buildings (in different States and built by different builders) have had bolts from the diagonal bracing connections come loose and fall out. On one of the buildings this has happened twice in different areas of the building. On the same building after replacing the first bolt that had become loose and fallen out I personally checked about 100 bolts in bracing connections (while I had a scissor lift and free access to the property) and found about a third were probably best described as finger tight.

Other than these three buildings I have never come across this before (I have inspected a lot of structures of this type) and have never read about it or heard colleagues raise similar issues.

Has anybody else have first or even second hand experience of this ?

 

[MotorCity]

The bolts should have been designed and installed as slip critical. To fix the problem, you can either prepare the faying surfaces and install the bolts as slip critical or weld the connections.

Unfortunately, it is not uncommon for these type of connections to be incorrectly designed and/or installed. I have found this issue to be more prevalent in small, prefabricated or "cookie cutter" type of buildings rather than larger, multi story structures.