Pozzi Chimney Sweep Blog

Two Major Signs Your Chimney Has Moisture Problems

If you suspect your chimney is experiencing water leaks or problems, call today for an appointment!

If you suspect your chimney is experiencing water leaks or problems, call today for an appointment!

For those unfamiliar with these terms, let’s define them for you before we answer the questions.

Spalling: to break into chips or fragments; to chip or crumble
Efflorescence: a white powdery substance or incrustation

(We can almost hear you,“Ohhhh that’s what it’s called. We are familiar with the concepts, but never knew the proper name.)

Over the years Pozzi Chimney Sweep has been called to repair many instances of spalling and efflorescence. We know they are serious issues that need prompt attention by a chimney professional.


In her article on the examiner.com, Marge Padgitt, Kansas City Alterative Energy Examiner, warns, “When chimneys spall, it is a sign of severe moisture penetration of the masonry bricks or stone. Spalling is the flaking off of a brick or stone surface, and is evident when the face of the masonry is missing. Pieces of bricks or stones may be found on the ground or on the roof, which is an indication that there is a problem”.

Too much moisture in the masonry is the primary cause of spalling. Chimney crowns that are not properly sealed, broken or missing bricks, soft porous masonry, and freeze/thaw/freeze cycles all contribute to the likelihood of spalling.

Excessive water and moisture are not a homeowner’s friend. Excessive rain, humidity, and freezing and unfreezing take their toll on masonry and cause spalling. While you may be tempted to use a commercial sealant to prevent water damage, if the source of the moisture is not eliminated, all you will do is trap the moisture…don’t be tempted! The damaged bricks must be replaced by a trained mason and the source of the leaks located and repaired.


Sometimes efflorescence is called “whiskers”. Salt deposits are the main component of the white residue. Why is this an issue? Because in order for the salt deposits to appear there must be water present, and like the situation with spalling, water is not a friend to your home. When efflorescence is on chimney bricks it could be from rain, but it could be coming from the warm air from inside the house forming condensation inside the chimney. Worse yet, the efflorescence could also be caused by a cracked or broken flue liner and gasses from your furnace. For an in depth explanation of efflorescence click here.

Whether your chimney is experiencing efflorescence or spalling, the result is damage to the brick and masonry of your chimney. Damaged chimneys cannot function properly and therefore put you and your family at risk for fires, toxic gas poisoning, increased heating bills, and structural damage to your home.

The Chimney Safety Institute of America (CSIA) recommends homeowners have a yearly inspection of their entire chimney structure by a CSIA certified technician. During those inspections, potential sources of efflorescence and spalling may be detected before you have major problems. If there is evidence of a problem your CSIA certified technician can make the necessary repairs to eliminate the influx of moisture and protect the integrity of your structures.

Pozzi Chimney Sweep is your go-to chimney contractor when it comes to chimney expertise in Northern Illinois. Call us for a consultation!

Cracked Chimney Crowns Cause Many Problems

Simply stated, cracked chimney crowns cause deterioration of your chimney! Because crowns are located on top of your roof, without a professional inspection from a member of the Chimney Safety Institute of America (CSIA) you may have no way of knowing there is damage being done until it’s too late. Pozzi Chimney Sweep, located in Illinois, knows that chimney crowns are subject to the elements and the effects the four seasons take on brick and mortar.

Cracked Chimney Crown - Aurora IL - Pozzi Chimney

Chimney crowns are the umbrella to your chimney. The purpose of your chimney crown is to prevent water from seeping into your chimney, and therefore must be functioning properly to do it’s job. Cracks, deterioration of the mortar, loose bricks, and other structural problems cause leaks and problems. Temperature such as wind, cold, rain, and heat all lead to chimney problems that must be addressed by a professional. Additionally, if you live in an area with seismic activity, even minor quakes can cause damage to the chimney’s structure.

Cracked or damaged masonry can lead to moisture accumulation ideal for the growth of moss and algae. When the masonry is worn or cracked away, water seeps into the brick causing structural damage. Water damage can also cause spalling and efflorescence which also weaken the brick.

Often, all that is needed is a chimney crown sealant. Sealant works if there are just a few very minor cracks and the sealant can help keep moisture from seeping into the brick, mortar, and concrete. If sealants are used alone, they probably will not last long and serve only as a band-aid and more extensive repair work will be needed.

In most cases, when there is apparent deterioration of the existing crown, you will need to hire a skilled and experienced professional to rebuild your chimney crown. According to the WiseGeek website, “When a chimney crown is added to a home, the homeowner should make sure it is made of the right materials. Masons will sometimes build a crown that isn’t up to par, and if the homeowner doesn’t know the difference, he’ll end up paying only to watch the chimney rapidly deteriorate over the next few years. The number one rule is to never use bricks. The whole reason for a chimney crown in the first place is because mortar isn’t weatherproof, so if a mason is using mortar and bricks to construct the crown that should be a warning sign. Instead, opt for metal, stone, or concrete slabs. Pre-cast or cast in place concrete crowns that are reinforced with steel are good solutions as well. Crowns can even be made of metal or stone, as long as they are water-tight and weather resistant.”

As a reminder, “The crown should slope down from the flue liner. The angle of this slope should be a minimum of 3 inches of fall per foot of run. Flat or low slope crowns can allow water to enter the interior of the chimney. A chimney crown should extend a minimum of 2 and 1/2 inches beyond the face of the chimney on all sides. This overhang helps to keep water from running down the chimney face. The bottom of the crown should contain a small kerf (drip). Without the kerf, water can roll underneath the crown and flow down the face of the chimney”, according to Tim Carter from Ask The Builder.

Cracked crowns are just one of the many potential hazards that a trained chimney professional can look for when doing their inspections. Like everything else, catching problems early mean lower repair costs and less damage.