A target piece for sealing mechanical penetrations in single ply roofing membranes is provided. The target piece comprises a left piece and a right piece, or a single unified piece. The left piece can be applied on one side of the one or more mechanical penetrations, and the right piece can be applied on an opposite side of the one or more mechanical penetrations. Alternatively, the unified piece can be applied on the one or more mechanical penetrations. Left and right curb elements are attached to a top of the left piece and right piece, respectively. Faces of the left and right pieces are sealed to each other and faces of the left and right curb elements are sealed to each other using an adhesive/heat seal, thus forming a pocket around the mechanical penetrations, and then sealant is poured into the pocket to seal the mechanical penetrations. Extensions are provided on ends of either the right or left pieces of the target piece to provide extra insurance against water leakage.