How to Block a Chimney

Written by christina sloane
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How to Block a Chimney
Install chimney caps to block animal access. (Jupiterimages/ Images)

Squirrels, bats, birds and other small animals are known to enter chimney flues to escape from the cold and build nests. The animals create a racket inside the chimney, and their nest materials and droppings are a serious hazard in active fireplaces. Animals dropping down the chimney and entering a home through the fireplace opening may frighten homeowners. To prevent these problems, homeowners can install a chimney cap to block animal access.

Skill level:
Moderately Easy

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Things you need

  • Measuring tape
  • Chimney cap
  • Screwdriver
  • Silicone caulk
  • Caulking gun

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  1. 1

    Measure the inside and outside perimeters of the chimney flue as well as the height of any tile that extends from the chimney. Order the appropriate chimney cap to fit the chimney opening.

  2. 2

    Slip a single flue chimney cap over top of the flue and secure it in place with the attached screws. This type of cap needs no further installation.

  3. 3

    Push an inside mount chimney cap inside the top of the flue. The friction of the sides of the cap against the interior sides of the chimney will keep it in place. If the flue is brick or tile, use silicone caulk to seal the gap. If the flue is metal, skip the caulk, since hot metal may cause it to melt.

Tips and warnings

  • Contact an animal welfare organisation to remove animals in your chimney before closing the chimney opening.

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