Nail gun depth control spacer

A nail gun and depth control spacer assembly for ejecting nails into a substrate, said substrate containing two or more layers of roofing materials at least one of which is compressible, wherein said nails penetrate the substrate but are prevented from permanently compressing said compressible layer, comprising:

• a nail gun including a driving cylinder having an inlet and outlet containing nails therein, a trigger mechanism for selectively actuating the driving cylinder, and a base portion associated with said outlet;
• a depth control spacer attached to said base portion of said nail gun to permanently remain thereon after discharge of said nails from said nail gun, wherein said depth control spacer having a semi-oval configuration composed of a pressure sensitive adhesive layer having a thickness of about 0.008″ to 0.06″ and a rigid layer of metal or polymeric material having a thickness of about 0.125″ to 0.250″ comprising:
• a distal end, a proximal end and a center portion;
• a horizontal top portion at the distal end;
• a first vertical side portion extending from the horizontal top portion towards the proximal end;
• a second side portion extending from the first vertical side portion towards the proximal end at a slight angle from the vertical towards the center portion;
• a third side portion at the proximal end extending from said second side portion and enclosing an obtuse angle forming the tip of the spacer;
• and
• an oval cavity having a longitudinal axis and a transverse axis in the center portion of the depth control spacer, the longitudinal axis of which points in the vertical direction, and the transverse axis of which points in the horizontal direction, wherein said oval cavity has a longitudinal diameter of about 0.95″ a transverse diameter of about 0.62″, and an arc radius of about 0.3″.