November 29th, 2013 10:53 PM by Dan Howard
There can be holes and openings in the mortar and brick components of the fireplace system. These are often prevalent in the area above the damper called the smoke shelf. The rest of the chimney should also be checked for these defects after cleaning by a chimney sweep using a camera system.
The reasoning for the cleaning is that creosote can and will cover additional openings. This is why cleaning and checking chimneys is a recommended annual activity.
There should not be any openings in brick or mortar from the lowest point to the highest point of the chimney. When openings exist, they must be repaired after the components are cleaned and checked.
The chimneys can also being damaged by leaks from the top of the chimney into the fireplaces. Properly sloping the top of the chimney and installing a chimney cap to protect from rain entering the chimney would be recommended.