Fastener failure

I have metal siding on a commercial building coming off in moderate winds. The proper self-tapping screws were used according to the manufacturer to fasten to the underlying metal studs. The manufacturer did not specify how many fasteners per panel or per foot etc. needed to be installed to correctly hold the panels in place. Is there anywhere that this information can be found?

 

[0theblacksmith0]

Hi-your best bet would be to locate the manufacturers/suppliers of the panels/cladding and obtain their recommendations.They usually supply full fixing recommendations and point out other important factors to consider before the product is applied to the building.
Hope this helps in anyway.
TW Weld.

 

[vonlueke]

Ensure tap drill holes are not being drilled slightly too big. The fasteners should not install extremely easily; but on the other hand, the pilot holes should not be so small as to cause partial stripping of the screw threads. With a few experimental tap drill hole sizes, you should be able to find the minimum allowable (optimum) tap drill hole size.

If tap drill hole size is already correct per the above description, consider decreasing the fastener spacing to approximately one half or one third the current spacing. This should double or triple the panel connection strength. Good luck.

 

[TheBlacksmith]

Are the fasteners too tight? Most of this siding is left slightly loose too allow it to move as it expands and contracts with temperature change. If it is clinched down tight, maybe that is stressing the fasteners to the point where the wind is finishing the failure.

Blacksmith

 

[vonlueke]

True. screwloose2: I should clarify, the optimum tap drill hole size I mentioned above refers only to the pilot hole in the underlying metal stud. The bolt hole through the panel itself, on the other hand, should be oversized so the self-tapping screw is not also tapping into the panel layer, and to allow thermal expansion per TheBlacksmith.

 

[CustomHardware]

Is the screw case hardened steel and the metal siding aluminum? This could cause a galvanic reaction leading to hydrogen embrittlement in the screw, causing the head to separate under load. The aluminum would be sacrificial and would ultimately also show signs of corrosion.