Chimneys & Flue Liners

Examples of (1)deteriorated  chimney caps, (2) typical cracking of chimneys due to freezing water or ground movement, and (3) improperly built chimneys or improperly installed gas fuel lines.

This chimney cap cracked years ago and moisture was allowed to freeze and split the "castle" around the top of the chimney.   A quick look at the cover over the flue opening tells us that the chimney has not been used for some time.


View of collapsed chimney cap.  Water enters chimney and can reappear on finished ceilings/walls.

This cracked chimney cap is very typical of most masonry chimneys.   The buyer was instructed to provide for a polymer seal over the cap to prevent continued moisture intrusion through the cracks and around the flue liner.

This view of a clay liner flue is from the top and you can easily see that the mason left at least one large gap between the tiles and other unknown materials are visible halfway down on the left side..   Gaps are not allowed in flues due to the hazard that escaping hot gases and creosote build-up present.


This view of a clay flue tile serving a fireplace below is scary.   Flue liners serving different appliances or fireplaces should never be unsealed or open to the other.   Escaping gases from one flue can enter the other fireplace and be drawn into the dwelling due to intermittent negative pressures within the dwelling air space.

The thin, black piping in the center of the photo is a natural gas line installed through the flue liner serving the basement fireplace in order to reach the gas log appliance installed in the family room (main floor) masonry fireplace.   Thankfully, the basement fireplace was never, ever used by the occupants.   The company who made this erroneous installation promptly corrected the problem at no charge when informed by the seller.


The white, powdery growth on the chimney masonry is called "efflorescence" and is present as a result of either a leaking chimney cap or leaking flashing.


View of chimney bonnet serving wood stove.  (Please forgive glare smudges in center of photo.)


Close up of creosote built up on chimney bonnet.  Looks like chimney cleaning day is here!


The brick mason left wood veneer strips in the mortar joints between the chimney "throat" and the clay liner in the center of the photo.   You can tell that the chimney has never been used.