Water is an essential to life, but it can be extremely detrimental to the life span of your fireplace wreaking havoc on unprotected chimneys. All masonry chimney construction materials, except stone, will suffer accelerated deterioration as a result of prolonged contact with water.
Many people don’t realize that Memphis, TN receives on average 54 inches of rain annually. That is 40% more than the average U.S. city’s annual rainfall total of 38 inches. Masonry materials deteriorate quickly when exposed to the freeze/thaw process common in the Midwest. Water and moisture in the chimney not only penetrates the brick, which weakens it, but also causes rust in steel and cast iron weakening or destroying the metal parts.
While most stone isn’t affected by water penetration, large chunks of mortar can crumble creating a very unstable and weakened chimney. Preventing chimney leaks or repairing chimney leaks during the rainy season should be a top priority of every homeowner as chimney repair costs can range from hundreds to thousands of dollars.
Hiring a chimney sweep to perform an annual inspection is a great way to catch problems before they reach the critical stage. In a chimney inspection, the chimney sweep will check for a missing or cracked chimney crown or cover, missing bricks, cracked mortar and loose or damaged flashing.
Four Key Chimney Repair Areas
Four key areas on your chimney are depicted in the above diagram. Most chimney leaks occur due to problems in these critical locations. Let’s take a few moments to discuss the importance of each.
Repair or install a Chimney Cap
Chimneys have one or more large openings (flues) at the top that can collect rainwater and funnel it directly to the chimney interior. Even a commonly-sized flue would potentially allow large amounts of water and snow to enter during just a single year. A chimney rain cap attaches to the crown and works like an umbrella to prevent leaks and clogs. If you ever notice water in the firebox or white smoke when you light a fire, you likely have a missing or damaged chimney cap. You should also replace your damper—The metal or aluminum cover inside the flue seals out the elements and protects the fireplace when not in use—if it’s damaged and compromised. Water, debris and such can reduce the dampers usefulness.
Repair or Replace a Damaged Chimney Crown
The chimney crown (or wash) is the top element of a masonry chimney. It covers and seals the top of the chimney from the flue liner to the chimney edge. A properly constructed crown should create a downward slope directing water from the flue liner out to the edge of the crown where the overhanging drip edge helps prevent erosion from water running down the side of the chimney. Many masonry chimneys are built using inadequate crowns constructed from common mortar mix and doesn’t allow for the proper casting or forming of a 2” overhang created when using a Portland cement-based mixture.
Inspect for Masonry Damage
Water leaks can occur anywhere around your masonry work and are very difficult to spot. Repair any cracked, missing, or spalling bricks and deteriorating mortar joints as soon as possible. Don’t forget to inspect the chimney crown. Water penetration can cause interior and exterior damage to your home and masonry chimney including; rusted damper and firebox assemblies, water stained walls and ceiling, clogged clean-out area, stained chimney exterior, decaying and cracked mortar and flue liner system, collapsed hearth support, and tilted and collapsing chimney structure caused by settlement. Masonry chimney repair should be performed immediately as a delay could lead to catastrophic damage.
Repair or Replace Loose or Damaged Flashing
Chimney flashing is what seals the space between your roof and your chimney. High quality chimney flashing is critical because it keeps rain and the water from melting snow from leaking into your house. The corners of your chimney are particular trouble spots. Unmonitored, these leaks can result in significant damage to the ceilings and walls of your home.
Annual Maintenance – Chimney Inspection
The number one question homeowners ask the chimney sweep is how often should an inspection be performed and at what level. It is recommended by the Chimney Safety Institute of American that a chimney inspection should be performed once per year. Even though the chimney may be structurally sound, during the off fire season animals such as birds often nest in the chimney creating an obstruction that should be carefully removed.
Inspection by an accredited, certified, chimney specialist with proper equipment–specifically designed to spot and prevent chimney leaks–is your best first line of defense to ensure a life-long enjoyment of your fireplace and to keep chimney repair costs at a minimum.
If your appliance or venting system has been under constant use and has not changed, a Level I inspection by a chimney sweep is recommended. When acquiring or selling a home or making changes to your home or appliance, a Level II inspection is the recommended course of action. Level I inspections consist of examining the readily accessible portions of the chimney exterior, interior, and accessible portions of the appliance and chimney connection. Your certified technician will be looking for basic soundness of the chimney structure as well as the flue and basic appliance installation and connections. Furthermore, he will also be verifying the chimney is free of obstruction.
Level II inspections are more in-depth inspection than a level I—including a camera visual inspection. When a level I or level II inspection suggest a hidden hazard and special tools are required to access concealed areas of the chimney or flue, a Level III inspection is recommended.