Lean one extension ladder against your roof, then the third step from the top is even with the eaves. Measure the flue or perimeter around double vent, with a tape measure to determine the correct size chimney cap. Dimensions outside length and width of a single tile or masonry fly that is square or rectangular. Measure the length and width of the chimney top, or outer chimney flue perimeter about twice, and measuring the height of the highest fly. Measure the outside diameter of round masonry or single wall metal chimneys. Set the bottom of a chimney covers around the outside of a single brick flue, so that it covers 1-3 inches of the smoke.
Sparks from a wood burning fireplace is a fire hazard to dry outdoor brush and trees. The top of a chimney cap keeps rain and snow from corrosion damper. A metal around the sides traps large particles burning and creates a barrier to keep animals from using your home as their Residence
Insert the bottom of a chimney cap in the inside of a round tile chimney and push it down firmly. Set the inside bottom of a chimney covers in the inside of a metal casing or pipe and push it firmly into the pipe. Sealers and glue recommended for metal pipes.