mg wrote:
There are 6 or 8 spiral nails on our deck that will not stay down. The
boards are flat on the deck and do not appear to be cupped or warped.
But, within about 3 months of driving the nails down, they are back
up.

Should I pull the nails and replace them with the next size larger
spiral nail?

Should I pull the nails and replace them with coated deck screws?

If this is an older deck, it could be a sign that the underlying wood is
rotting.