Fix Roof Flashing Around Chimney

To repair loose roof chimney flashing.

Fix roof flashing around chimney.

Flaws in the roofing material above or adjacent to the chimney there may be a broken slate or tile nearby that is causing a leak. Water test the roof at the area of the chimney using a garden hose. Step flashing on roof peak. Roof shingle over step flashing.

Use masonry nails or screws to reattach the flashing tight against the chimney. Use special masonry caulk to seal the joints between the flashing and the chimney. Renew flashing seals by chipping out the old mortar and caulking along the edges of the flashing. To do this ask an assistant to observe the area of the ceiling near the chimney and run water along the sealed gaps of the.

Seal the seam between the cap and step flashing with urethane roofing cement or silicone caulking compound as shown at right. Clean any leaves or other debris out of the gap between the flashing and chimney. Apply a generous amount of roofing cement behind the flashing. If you do not wish to form your own corner flashing you can buy pre bent pieces and cut them to size or use a piece of corrugated aluminum which is easier to bend.

For tile roofs the underlayment which keeps water out may be deteriorated. Bend the corner flashing tightly around the corner.