How to Properly Repair Crown & Brick Chimney

Chimney Crown Repair

• 1

  Scrape the crown surface clean with a stiff-bristled brush to remove any moss and debris.

• 2

  Patch minor cracks using fire-rated silicone caulk.

• 3

  Break apart deteriorated sections using a cold chisel and hammer.

• 4

  Brush debris from the broken-up sections off the crown.

• 5

  Spread an even layer of patching compound around the entire crown using a trowel. Make sure to maintain a slight slope to force water off the crown and away from the flue.

• 6

  Fill in any space that remains between the crown and the flue or flashing with fire-rated silicone caulk.

Mortar Joint Repair

• 7

  Remove loose or crumbling mortar from the joints. Use a chisel and hammer to knock this mortar out of the joints to a depth of 1/2-inch. Remove mortar from vertical joints first, then follow with the horizontal joints.

• 8

  Brush any remaining dirt and debris out of the joints with a stiff-bristled or wire brush.

• 9

  Dampen the joints where the mortar will be placed.

• 10

  Prepare mortar for the joints according to manufacturer directions. Make sure to use a type of mortar suitable for exterior applications. It may be necessary to mix a coloring additive into the mortar to match the existing mortar.

• 11

  Pack mortar into the joints, beginning with the vertical joints. Strike the joint mortar flat.

• 12

  Remove excess mortar or use a jointing tool to finish the joints once the mortar begins to harden.