is a phenomenon occurring when applying a protective coating (or lining) to concrete (predominantly vertically cast-in-place) where air becomes entrapped within bughole
cavities and releases into or through the protective coating
, thereby causing pinholes and holidays in the coating film.
As a requirement of the SSPC-SP13/NACE No. 6 Surface Preparation of Concrete Joint Standard, bugholes are to be filled prior to coating application.