A 3rd nail is when 3 or more nails are added to the metal fasteners that attaches the wall of a house to the roof truss aka roof to wall connection. This is something that would go on a wind mitigation form for a homeowner’s insurance policy, which is provided by a licenses home inspector.

3rd nail is technically the wrong term for this, but is how it is most commonly known. A home inspector will go into the attic to look for this information and determine how to write up the wind mitigation. The roof to wall connection without 3 or more nails would be either a “toenail” or “single wrap” and then once that extra nail is added you would hear it referred to as a “clip” or “double wrap”.

This simple step makes the roof much more secure against strong winds, which is why the homeowner would receive a larger credit on their insurance policy.