Creasing: Is It from Wind or Hand Lifting?

Posted by in Shingles, Simple Forensic Methods, Wind Damage | December 02, 2019

Multiple lines of creases in the height of a tab often raise suspicion that the damage has been due to hand lifting, that is, intentional damage.  But, that is not true.  There is more to consider. 

If the multiple lines of creases are contiguous, that is, near to each other and the tab is unsealed (or partially unsealed), then they are probably due to repeated lifting of the unsealed portion of the tab by repeated winds.  Additional supporting evidence may include graying of the exposed asphalt and/or heavier accumulations of dirt on the sealant.  (See featured photograph).

If the multiple lines of creases are separated, especially if one is along the sealant line (Figure 1) or if creases can be better explained by another damage producing phenomenon (Figure 2) then there is reason to suspect hand lifting.  Additional supporting evidence may include cohesive failure of the sealant, dark coloring on the exposed asphalt, a relatively clean surface on the sealant, and/or a tackiness on the sealant. 

Figure 1 Creases at top of tab and at sealant line.
Figure 2 Creasing from hand lifting to drive nails during repair work.

The crease along the sealant is due to lifting the tab along the edge and the additional creases near the top of the tab are due to the tab being folded back (not just lifted) multiple times.