Do I Need a Chimney Thimble

Running any residential or building heating appliance, burning gas, liquid, or solid fuels through a combustible wall, will require an Insulated Wall Thimble as your passageway to connect appliances to interior or exterior masonry chimneys.

What is a masonry thimble?

A masonry thimble is a round, terracotta cylinder extending through the chimney wall into the flue. The hole is usually 6 or 8 inches in diameter and is designed to accept stove pipe.

Do I need a bend in my chimney?

Both the Regulations and the Standards recommend that bends in the chimney be avoided, as a straight vertical chimney performs better. If bends are necessary there must be no more than four in the length of the chimney.