Why Does My Chimney Have White Stains?

White staining, or efflorescence, is caused when excess moisture within the chimney structure seeps through the bricks and evaporates on the outer surface. The white discoloration is caused by naturally occurring salts that have been washed out of the bricks.

Water and bricks don’t mix

White stains on a chimney aren’t a huge problem in and of themselves – it’s not hard to wash them off with a strong cleanser and brush. But, the fact that enough water is getting into your bricks to cause stains can be a concern.

Most chimneys are built with porous bricks which can absorb water from rain and melting snows. Water can also infiltrate through cracks from a variety of situations, including:

• Old age
• Shifting/settling of the house
• Gale-force winds
• Lightning strikes
• Earthquakes
• Violent hail storms

The Cycle of Deterioration

These cracks can go unnoticed until the damage becomes severe. Once bricks begin to deteriorate – whether or not you can see it – they will continue to degrade. A little damage can spiral into situations where bricks fall out and the chimney develops a lean or even, in the worst cases, collapses. This is why it’s important to schedule chimney inspections every year. Our trained professionals can identify issues early and fix them before the damage becomes severe.

Can Water Get In Any Other Way?

Aside from cracks in the structure, water can infiltrate through missing or damaged chimney caps and damaged chimney crowns. Both of these components sit atop the chimney and serve as blocks to prevent water from getting into the flue.

Chimney Cap

The chimney cap covers everything at the top of the chimney. It not only keeps water out but also prevents tree debris and small animals seeking shelter or nesting grounds from getting in. If a chimney cap is badly damaged, ill-fitting or not there at all, water has an easy path into the flue.

Chimney Crown

The chimney crown is the cement layer that covers the top chimney bricks and should have a sloped design with an overhang. If the crown is cracked, water can seep in and eventually cause serious damage, allowing more water to start another cycle of deterioration below the crown.

If you have white staining on your chimney

If your chimney is stained white, the first step is to schedule a certified chimney inspection. The inspection will determine where the compromise exists, the severity of the damage and the best course to take in repairing the problem.

Repair could involve seal-coating the bricks, replacing missing bricks/mortar, or partial or complete chimney rebuilding, among other options. These all have the goal of restoring structural integrity and safety to your chimney.

When you notice white stains on your chimney’s exterior, call Black Moose Chimney & Stove of Antrim, NH, to get the problem fixed. Our team is certified by the Chimney Safety Institute of America, which means the person working on your chimney has demonstrated the highest level of skill and training in the industry. Fill out the form below or call us today at (603) 525-7905 for a job done right the first time.