04/13/2026
The first picture is the underneath decking of a roof I inspected, looking at it from inside the attic. If you have gaps between your deck boards that are 1/4” or bigger than your roof deck is no longer up to code and this photo shows you exactly why.
This nail that’s coming through isn’t secured to anything which makes your shingles more susceptible to blow offs in high wind events and, not to mention, more dangerous to walk on if it’s steep.
That’s why we overlay sheets of OSB with H-clips to provide the perfect spacing for expansion and contraction to create a solidly sheathed deck that secures the shingles and provide a substrate manufacturers will stand behind. You can see that in the second photo.
