This quick easy to use tube of Black Jack All-Weather roof cement that is fiber reinforced will repair and stop roof leaks effectively. It will seal flashings and other roof projections. Use on near and around vent pipes, spouts, valley, skylights, gutters and chimneys. Also, it can be applied to seal cracks in exterior chimneys, walls and foundation joints. Its pliability also allows its application for lining gutters and troughs that leak.