How to Repair Leaking Chimney Roof Flashing

Roof flashing around chimneys can separate from the brick, allowing rainwater to leak inside the house. To repair loose roof chimney flashing:

    1. Clean any leaves or other debris out of the gap between the flashing and chimney.
    1. Use a chisel to remove any hardened roofing cement.
    1. Apply a generous amount of roofing cement behind the flashing.
    1. Use masonry nails or screws to reattach the flashing tight against the chimney.
    1. Cover any exposed nail or screw heads with roofing cement.
    1. Apply roofing cement to the joint between the flashing and brick.
  1. Smooth the roofing cement out with a paint stirrer or putty knife.

Watch this video to find out more.

Further Information

The “L” shaped flashing that protects the joint between a roof and a chimney can sometimes pull away from the chimney, especially if it’s only held in place by roofing cement. Begin correcting the problem by removing any leaves or debris from the void, and then scraping or chiseling the dried roofing cement off of the bricks so the flashing will lay flat against them.

Now, apply a generous amount of new roofing cement to the bricks behind the flashing an inch or so below the top of the flashing. Use masonry screws or nails to hold the flashing tight against the bricks before you apply more roofing cement along the top edge of the flashing.

Finally, smooth out the cement with a putty knife, and apply cement to the heads of all the fasteners.


  1. Gus and Grandpa:

    In much of California cement tile roofs abut a wood framework around the chimney, which is in reality, is a flu pipe in a wood box. I would assume that the process is much the same when the flashing pulls away from a brick chimney.

    I can see that at least one piece of roof tile has slipped about six inches and a dam has been created where debris and dirt has built up. There has been well over 20 inches of rain this rainy season, and water has collected here and made its way over the flashing, or through a fastener hole and has damaged about eight panels of plasterboard. I can also see where mold or mildew has begun to show as well.

    Can you offer suggestions as to how to go about inspecting a tile roof and how to choose to replace or repair broken tiles, especially those along the ridge line?

    Since we are renters, we’ll leave it to the property manager to have the actual repairs made. But knowing that he may ask his totally incompetent handyman to make the repairs, I want to be able to insist upon a roofer doing things correctly the first time.

  2. I spent all day patching the top of the chimney wel a little rain it came back in the inside wall where the shingles meet the chimney , the water is setting there and under the shingles, I think this is where the water is coming in, I am not a roofer but a little common sense go’s a long way’s, I am 66 years old and this is not my first time on the horse.

  3. As I own new house in Australia I would like to fix chimney on the roof on top of Laundry and cookers
    Please advise which handyman can fix is roofer or plumber

  4. Had new shingle roof installed not replacing the metal flashing. The flashing is there for a brick wall and with roof on 6/12 pitch. The installers left the original flashing which did look good to me. My problem while installing the new shingles they nailed flashing at the bottom which I thought was wrong? Nail at top?

  5. I want to replace the chase cover on my chimney, and also the fascia directly below the cover.
    Can I get a stainless steel chase cover that has a longer overhang (about 5 inches) that would also cover the fascia? This way I would save the cost of replacing the fascia.

    • Hi, Martin,
      Need more information about this topic? 
      Connect one-on-one with a home improvement pro immediately through JustAnswer, a Today’s Homeowner partner:
      Good luck with that chimney and fascia! 


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