532 Norfolk Avenue, Buffalo, NY 14215

AN INTRODUCTION TO CHIMNEY REPOINTING

Our family has two generations in the roofing & chimney repointing industry. We stand behind our assessment process and our work. This gives our customers confidence that our crews are highly trained and deeply experienced. You always receive top workmanship backed by our business integrity. We can show you examples of our work in your area!

Why Chimney Repointing is Essential

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Repointing is a necessary component of chimney masonry maintenance. Well done mortar joints can last for 25 years before repairs are needed, but the brick that surrounds them can easily last 100+ years. Weather plays a large factor in determining how long your mortar joints will last.

Western NY is known for its unique blend of weather. Sandwiched in by the Allegany Mountains to the South and Lake Erie to the East, our weather is unpredictable. When the weather begins its steady descent into winter, we’re especially susceptible to changes in temperatures, rain turning into sleet into snow, followed by a crisp and sunny winter day. This weather might mess with your head, but it slowly destroys your masonry. Moisture is absorbed into brick and mortar, and with the temperature fluctuations the water expands and contracts. If brick and mortar were equally strong, this thermal expansion would cause irreparable damage to brick and mortar.

For this reason, the compression strength of mortar is less than the brick. As temperatures fluctuate, the expanding brick overpowers the expanding mortar. Over years of thermal expansion cycles, this will cause enough damage to the mortar that it will need to be repaired. If mortar wasn’t calculated to be softer than bricks, regular reconstruction of your masonry would be necessary.

Repointing is the process of renewing the pointing, which is the external part of mortar joints, in masonry construction. Over time, weathering and decay cause voids in the joints between masonry units, usually in bricks, allowing the undesirable entrance of water.

Chimney Repointing Process

Repointing a masonry chimney requires a skilled professional. Repointing is far more than just slapping some mortar into cracks. The process requires different skills than traditional masonry, and even masons with years of experience might not have significant experience repointing brick.

  • Assessment: The biggest challenge of repointing is determining the extent of the mortar damage and removing damaged joints without causing new damage. Generally, an expert starts with a visual inspection where erosion deeper than 6mm, crumbling mortar, and cracks between brick and mortar or within the mortar are noted. After the visual inspection, specialized tools such as metal scrapes or special low pressure water sprayers might be used to determine the extent of the damage. Once the determination has been made, the deteriorated mortar joints must be removed.
  • Removing mortar joints: It’s important that the joint be removed to an appropriate depth without causing extra mortar or brick damage. Once the joints are removed, the new mortar must be mixed. This mortar should be as similar in composition to the existing mortar as possible, lest thermal expansion cause the mortar to react differently to the pressure of expanding brick. Ignoring this step could lead to premature mortar deterioration. Using mortar with excessive compression strength can cause permanent brick damage, such as cracking and splitting.
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  • Applying mortar: The correct mortar is then placed between the brick by layering, compacting and tooling. This helps adhere the old mortar to the new, and ensures a snug fit between brick and mortar.
  • Professional masons experienced in repointing also take care to match the shade of the new mortar to that of the old. This is purely aesthetic, and keeps the chimney repointing from looking sloppy. A skilled mason will do this with minimal mess, and will ensure the brickwork is clean before finishing the job.
  • Applying Sealant: Finally, a waterproof sealant is applied to the fresh repointing. This will help prevent water from permeating your chimney, and thus will help extend the life of your mortar joints.

Get the Chimney Checked

While all masonry will need repointing at some point, chimneys are particularly susceptible to water damage. Their location subjects them to constant temperature changes while making them difficult to monitor for signs of damage. Before fall slides into winter, have your chimney inspected for mortar damage. Timely chimney repair can save you money, and our free masonry inspection will give you peace of mind that your chimney will be sturdy and safe all season.

Beautiful Curb Appeal

Crumbling mortar can make your property look unkempt. Indeed, if your chimney is a period style, it might mean that you start to lose definition in its design. Repointing has many functional benefits, but it is also important for ensuring your chimney looks neat, presentable and attractive, and is a great way to bring out the distinctive details of your chimney. 

8 Clues That Your Chimney May Need Repairs

Using a fireplace safely is directly dependent upon having a chimney that is sound, able to keep out moisture, unobstructed, clean, and in overall good condition. Homeowners sometimes forget that a chimney needs maintenance and should be inspected. A damaged chimney can be a serious fire hazard and should be repaired as quickly as possible.

How do you know if your chimney needs repair? 

You may need to climb on the roof to spot this clue; but if your chimney crown is cracked, there is probably damage that will only become more extensive and more costly to repair until the problem is fixed. The crown is an essential feature of the chimney structure because it provides the first line of defense against harsh outdoor elements. When a chimney crown is cracked, moisture can seep in and create bigger cracks. In addition, it’s a sign that water may be seeping between the flue lining and chimney, which can create shaling and spalling – see more about these signs of damage below.

One way to help protect a chimney crown and chimney from damage is to weatherproof it, a measure which also helps prevent, to an extent, all of the signs that a chimney may need repair.

Another problem you may need to visit the roof to discover is deteriorating mortar joints.

It’s important that the mortar is in good condition; otherwise, the masonry is exposed to more moisture, which can cause the entire chimney to rapidly deteriorate. The added moisture causes the most harm during winter, when moisture inside the masonry can freeze and thaw, causing large cracks to develop. When damaged mortar isn’t addressed, chimneys tend to collapse, which requires even costlier repairs.

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Bits of masonry breaking off of the outside of the chimney is caused by spalling. Moisture that gets into masonry can force the surface of the brick, stone, or concrete to pop out, flake off, or peel off. Spalling masonry should be replaced as soon as possible, to stop the crumbling process, which can obviously lead to chimney collapse.

Similar to spalling, shaling is when the inside of the flue tile begins breaking off, and you can see bits of chimney tile in the hearth. The flue lining must be in good condition for a fireplace to be used safely. Cracked flue tiles are an indication that heat from the chimney could enter parts of the home which are combustible, leading to a house fire. It can be difficult to determine whether a flue lining is in good shape. During recommended annual chimney cleaning and inspections,

Our professional chimney sweeps use a special camera to closely examine the flue liner and make sure that there are no cracks or signs of crumbling.

Rust in the firebox and a rusted damper are both clear signs that excess moisture is making its way into the chimney. The moisture which causes rusting could also be causing safety hazards, such as deteriorating flue tiles. Since rust is a sign of a bigger problem, a professional chimney sweep should be contacted to examine the condition of the chimney, without delay.

White staining on chimney masonry is called “efflorescence.” Removing the staining isn’t complicated, but cleaning it doesn’t solve the issue which causes the white residue. Efflorescence is a clear sign that there is excess moisture in the masonry. Premature deterioration of the chimney will likely occur, if the moisture problem isn’t resolved.

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A good clue that you probably have moisture in the chimney system is if the wallpaper on the walls near the chimney is damaged. Ruined wallpaper is usually a result of moisture in the chimney. Before continuing the use of the fireplace, call one of our professionals to locate and repair the source of the problem.

Chimney fires are dangerous and a clear sign that the chimney is probably in serious need of cleaning. A few circumstances which can help you identify that there is a fire inside of your chimney include:

  • Flames are leaping from the top of your chimney.
  • There is a roaring sound like a train or an airplane flying nearby which can probably be heard even by your neighbors.
  • Dark smoke billows from the chimney top.
  • You may hear something that sounds like a loud sucking sound or pipes that are rattling.

Chimney fires can cause serious structural damage as well as house fires.

If you spot any of the above-mentioned clues that your chimney may need repair, contact our certified professionals. Even if you don’t see any signs of damage, it’s a good idea to get your chimney cleaned and inspected during spring or summer. That way, you could learn about damage in plenty of time to get needed repairs before winter.

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