How to Replace Metal Chimney Flashing

If your home has a chimney, then it is necessary that flashing be part of the chimney's assembly in order to keep a roof from leaking. The flashing protects your roof by preventing water seeping in the chimney. When a leak develops, replacement of the flashing is the only remedy for the problem. 

Supplies

• Utility knife


• Pry bar


• Paint scraper


• Replacement chimney flashing


• Tin snips


• Hammer


• Nails


• Drill


• Expanding anchors


• Caulk


• Caulking gun

1. Trim the sealant away from the chimney mortar with the utility knife.


2. Pry up the shingles around the edges of the flashing. Lift the shingles back far enough until the flashing's edges are exposed. However, do not remove the shingles.


3. Drill out the old flashing anchors.


4. Pry the flashing loose from the chimney and the roof with the pry bar.


5. Pull the flashing from the chimney.


6. Remove any left-over roof caulking by using your paint scraper.


7. Measure and cut the new flashing base. Make the pieces the same size as the ones removed. Bend the flashing and put the front base into place.


8. Bend the corners of the flashing  by hand and wrap them around the sides of the chimney. 


9. Repeat the process for the back and sides.


10. Use the caulking gun to secure these in place.


11. Nail the shingles back in place. Use the caulking to seal the area.


12. Place the chimney saddle over the chimney and nail in place.


13. Fit the front cap on the chimney's corners. Tap it into place in the mortar with the hammer. 


14. Use screws to attach it.


15. Cut and place the side and rear caps of the flashing into the mortar grooves, using the same process as before.


16. Drill holes into the caps and insert plastic anchors to hold them in place.


17. Seal the flashing with caulking where the mortar was tapped into the grooves.