While the bricks and mortar of your chimney is designed to withstand the elements, there is one force that can cause serious damage – water. Moisture can wreak havoc throughout your chimney system, causing leaks, rusty parts, and masonry deterioration. However, the presence of moisture can also show itself in unique ways, including chimney discoloration or staining. The following guide can help you identify the kind and source of your chimney staining – as well as how you can keep it from coming back in the future.

Water Leaks and Exterior Chimney Staining - Houston TX - Lords Chimney

Red or brown stains

If you have a prefabricated or factory built chimney, red or brown stains on the chimney chase are often the result of rusting. Long-term exposure to moisture – especially from puddles of standing water – can cause the galvanized metal found in many chimney chase covers to deteriorate and rust. The rusting chase top then causes dark red, brown, or orange staining to appear on the sides of the chimney. Rusted chase covers should be replaced with sturdier metals such as stainless steel or copper to prevent rusting from occurring again.

White stains

Crystalline or powdery white stains or discoloration are caused by a phenomenon known as efflorescence. Efflorescence occurs when water trapped in the masonry evaporates, leaving behind a concentration of white mineral salt.

Efflorescence is more commonly seen in areas where ground or rain water has a high salt content. Water from hoses, sprinklers, or rain can all cause efflorescence to occur. However, interior efflorescence may indicate that you have a leaky chimney; only small amounts of moisture are required to leave behind the mineral white chalky salt after evaporation.

Dark green stains

Dark green stains or discoloration is typically caused by the growth of algae on masonry. In order for this type of discoloration to occur, water must continually flow or pool over one area of the chimney structure. This type of long term exposure to moisture can foster an environment for algae growth – as well as mold or mildew – on the chimney.

What about inside?

While water can wreak havoc on your masonry outside, it can cause an equal number of problems indoors as well. One of the most common signs of a chimney leak is the presence of water in the flue, firebox, or on surrounding walls or ceilings. However, it can be difficult to tell the difference between a roof leak and a leaky chimney; because of this, you may want to have a certified chimney sweep have a look at the chimney before you or your insurance company pay to have the roof inspected and repaired.

Staining on your masonry could indicate that your chimney has a water leak. For more information on identifying chimney stains or to schedule a chimney inspection, contact Lords Chimney today!