Re-screwing

David, Thanks for your question about metal roofing. It is pretty common to replace compromised screws with a slightly larger diameter screw. This works well with dimensional lumber which has quite a bit of excess strength. I am not so sure about OSB. Especially concerning is the possibility of deteriorated OSB. Depending on the amount of OSB deterioration, just replacing with larger fasteners may not be effective. Clearly if you try larger screws and they tend to strip out of the OSB, then additional work is needed to support the panels. I would recommend having an MRA contractor come and evaluate. There is a 'Find a Contractor' function on the MRA web site. Regards, David Stermer