Does your Chimney System Need a Makeover?
White staining on the chimney is called “efflorescence,” and it only occurs when there are salt particles in natural masonry coupled with a moisture problem. When there is excess water in the chimney structure, soluble solutions move through the masonry and evaporate on the other side, resulting in a deposit of salt residue. The salt becomes a powdery or white crystallized substance on the brick, stone, or block masonry. Over time, the crystallized substances begin to look fuzzy or fluffy.
The staining isn’t always white. Sometimes the compounds within the masonry cause the salt deposits to be yellow, brown, or green. Whatever the color, when you see staining on a chimney, you are seeing evidence of a chimney in need of repair. There are also three conditions which exist; otherwise, there would be no efflorescence on the chimney:
- The masonry structure contains soluble salts.
- There is enough moisture within the masonry to create a soluble solution containing the salts.
- There is a way for the salt to move through the structure and evaporate on the exterior, leaving behind the white staining.
There are many different potential causes of excess moisture in the chimney masonry that results in efflorescence. The chimney cap could be cracked, allowing rainwater to pour between the chimney and the chimney flue and to wear away the mortar. When mortar isn’t doing the job of sealing off the masonry, water gets in, causing accelerated wear and tear and other problems.
Chimneys are far more vulnerable to the damaging effects of rain, snow, wind, and ice than exterior walls because all four sides and the top of chimneys are exposed. When there are freezing temperatures in winter, there is a continuous expansion and contraction of the chimney masonry. Not only that but also the toxic gases from the fire contribute to deterioration. The frequent movement of the masonry results in wear and tear. One of the first problems to arise with a chimney is the need for new mortar.
Chimney masonry can last about a century, but the mortar that seals the bricks and holds them in place only lasts about a quarter of a century. Once the mortar begins to crumble, moisture gets in, which results in even more expansion and contraction.
If damaged mortar isn’t replaced, a chimney will begin losing structural integrity. When a chimney begins leaning, it may not be possible to fix it without at least a partial rebuild. It’s unsafe to have a leaning chimney because it could fall and seriously injure someone. Using the fireplace when the chimney is damaged is dangerous, as well, because the combustion materials may be obstructed from exiting, which can cause smoke and toxic fumes to enter the home.
The smoke in a fireplace is supposed to go up the chimney, but sometimes it goes into the home. Over time, the area above the hearth can become unsightly due to black staining. A chimney professional can help identify the reason that a chimney isn’t operating properly and can help stop the continued problem of smoke staining. Possible reasons for the black soot above the hearth include an obstructed chimney, a chimney that’s the wrong height, and negative air pressure in the home.
Contact our chimney professionals if your chimney is in need of a makeover. We can provide all of the repair or rebuilding services that may be needed to solve the problems.
Northeastern Chimney, Inc
37 Cody Street, West Hartford, CT 06110