How to Repair Damaged Chimney Flashing

Chimney flashing must be inspected regularly for leaks and damage. Chimney flashing is very important, because it protects our home from water penetration and mildew. To repair damaged flashing, you can use flash sealants. Just follow these simple steps.

Step 1 – Clean Up

Use a small broom or brush to sweep off any dust, dirt or debris on the area to be sealed. This is important, to make it free from particles that could work against the sealant system.

Step 2 – Cut Fabric

Measure the reinforcement fabric to completely cover the area for repair. Allow 3 inches allowance, so you can wrap it around the side of the chimney.

Step 3 – Mask Off

Mask the roof and chimney using a duct tape. This should not be less than 1 inch from the reinforcement fabric.

Step 4 – Base Coat

Apply a heavy base coat of flashing sealant, about 1/8 inch thick. Stay inside the masked area.

Step 5 – Seal

Embed the reinforcement fabric in the base coat and apply another layer of sealant to completely cover the fabric. Cut slits at the fabric’s end, to wrap around the chimney corners. Repeat for the 2 chimney sides.

For the high side, follow the same steps but measure off the reinforcement with a couple of inches more on each side to wrap down. Finish off the chimney flashing repair job by taking off the duct tape.