Staining

You many have noticed some discoloration throughout the chimney brick or stone, particularly in the upper portion. Stains can really tell a lot about what’s going on inside and outside of a chimney, so pay attention to them and let them speak to you. 

White external stains called “Efflorescence” is actually a symptom of water leaking into your chimney system, and can lead to costly damage with premature deterioration.

Brown external streaks are either going to be from rusted metal above or oil heater exhaust residue.  Both can be resolved once identified properly.

Brown internal stains are most likely water related.  This can be moisture coming from the elements outside in or from your heater exhaust inside out.  

Black external staining is typically the result of a poorly performing wood, oil, or gas burning appliance that is producing an excessive amount of soot.  Maintenance would be the best place to start in this situation. Alternatively, if the stain is isolated to areas around roof lines or gutters, it’s indicating that there is a consistent amount of water movement across and possibly within the masonry.  This should be examined thoroughly to make sure structural damages do not occur.

Black interior staining could be either smoke residue or mold growth depending on where it’s located.  If the staining is above a fireplace or on your ceiling, there’s a good chance it’s from smoke.  If it’s on the wall at ceiling level, above your mantel, or at floor level you may have a water intrusion problem and potential mold growth.