Black Jack 2172 All-Weather Roof Cement is a black asphalt product ideal for sealing, filling and patching cracks and breaks in roofing surfaces, firewalls, chimneys, gutters, flashing, etc., particularly where emergency repairs of wet surfaces must be done. Use this product to repair shingle tabs, flashings, roof seams and gable joints. It can also be used to stop leaks around vent pipes and is suitable for sealing metal building seams, foundations, masonry steps and for repointing chimneys. Cannot be painted.