Do I Need My Chimney Crown Sealed Or Repaired?
This is a smart question to ask, because a damaged chimney crown can lead to serious problems that are expensive to fix. A chimney crown is made of cement and covers the entire top of the chimney except for the flue opening. Its purpose is to protect the chimney from water, which is a chimney’s worst enemy.
When water infiltrates cracks in the chimney crown, it will begin a process of damage that can eventually require a complete or partial rebuild of the chimney. Most homeowners, if they get up on their roofs, can spot cracking in their chimney crown. They can’t, however, assess any damage that could be present down in the flue. For this reason, only a certified chimney inspector should perform annual service calls and make recommendations for the repair of damage.
Chimney crown sealing
In the early stages of crown damage, the only problem may be small cracks within the structure. In this case, a special waterproof sealant can be applied to prevent further decomposition. This compound provides a strong, water-tight seal but remains flexible so it itself doesn’t crack should extreme winds or house-settling cause the chimney to shift.
Replacing the chimney crown
If the crown is damaged to the point it must be replaced, only a skilled stone mason or chimney repair technician should be hired for the job. Chimney crown replacement involves careful grinding and chiseling to remove the old crown and not damage the underlying structure. Flues are wrapped in a material designed to prevent cracks. A drip edge is placed around the crown, then new concrete
is added to build the crown with sloped sides to encourage water run-off.
New chimney crowns require a drip edge, or overhang, that’s a minimum of two inches wide to keep rain water from running down the masonry, which would eventually damage the structure. Brick is a porous material and easily absorbs water. Any cracks in the mortar also will pull water in. The brutally cold temperatures during Wisconsin winters will cause infiltrating water to freeze and expand, further degrading the chimney structure.
As an added precaution, the chimney technician will grind a line below the limestone edge, so water won’t be able to drain back and come into contact with the chimney. This and the drip edge are both supported by the Chimney Safety Institute of America, leaders in the industry who know the best way to prolong the life of a chimney is to keep water away from it as much as possible.
Chimneys are built to last for decades, but various components often need repair or replacement during that time to keep the structure operating safely and efficiently. Again, when scheduling any work on your chimney crown or any other component, hire only trained professionals with verifiable experience.
Chimney Specialists of Highland, WI, employs certified chimney sweeps and chimney repair technicians who will make sure your entire fireplace/chimney system is in top condition all year long. Call us at (608) 929-4887 to arrange for an inspection or cleaning, or to get your questions answered.
