AskCodeMan

Jerry, I inspected a condo with roofing nails and drywall/sheetrock screws, both with exposed heads, attached to the roof decking. What would be acceptable and unacceptable fasteners and methods?

Thanks,
Peter from The Blizzard State of NJ

Hi Peter,

First, a question: Are you sure it was attached to the roof decking and not something else?

That in and of itself is a problem. How thick is the roof decking - the standard drywall nails/screws are going to penetrate any reasonably decent thickness of roof decking, and that would create great potential for leaks. By "reasonably decent thickness of roof decking" I am referring to 1/2", 5/8" or even 3/4" roof decking - if the roof decking was over 1" that *might* work, but even then, the nails/screws might penetrate through the roof decking.

The nails you are referring to as roofing nails are likely drywall nails as they also have a large head, although roofing nails are typically galvanized and drywall nails are typically blued, both to resist corrosion.

The pattern varies depending on whether you are looking at a wall or a ceiling (nails need to be closer together on the ceiling than on the wall), and whether or not you are looking at drywall nails or drywall screws (nails need to be closer together than screws).

If nails and screws are mixed, then the pattern needs to be the closer spaced pattern required for nails - I should clarify that statement: *IF* the screws meet the screw pattern, or *IF* the nails meet the nail pattern, then intermixing them does not harm, however, *IF* the screws do not meet the screw pattern, installing nails between the screws does *not* make up the difference (unless enough nails were added that the nails meet the nail pattern).