Chimney Shoulders: The Ins and Outs of Construction, Inspection, and Repairs
In conducting a chimney repair, there’s more to it than simply laying down bricks and building up above the home. The construction of a chimney can often times be a work of art in many ways, and when you start to identify the different parts and their individual purposes on a chimney, you’ll see why great care is necessary when constructing, inspecting, and repairing a chimney.
Nowhere else is this truer than when it comes to the shoulders of a chimney. In this article, we’re going to take. Look at what a chimney shoulder is, what it’s purpose is, how to properly inspect it, along with performing repairs that make the chimney look brand new.
What Is A Chimney Shoulder?
A chimney shoulder is an area on any stack where the chimney begins to narrow. The bricks are placed in a way that they gradually move inward before settling on a narrower path. Typically, chimney shoulders will need more repairs than other parts of the chimney because of their slope.
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Because the chimney starts to narrow as the masonry is higher, the slope can often feature ledges that prevent rainwater from draining away from the brick and stone. Over time, water leak and mortar can be a bad combo and lead to degradation.
How Are Chimney Shoulders Constructed?
In traditional construction, builders would simply step the bricks in gradually until they reached their desired width for the top of the chimney. They typically didn’t waterproof or protect this delicate area either, which would lead to all sorts of problems down the road.
Why Chimney Shoulders Are Typically Damaged
If you look at an older home with a chimney shoulder, you can typically see the water damage at play, as the bricks of the shoulder will appear darker than the rest of the chimney. This means that they are holding onto water more than the rest.
If you take a closer look at a chimney shoulder like this, you’ll see that algae and moss are present on and inside the bricks and they hold onto the excessive water entering the area. Mold begins to grow and darkens the appearance of the once pristine bricks. This is not only unsightly but can also be dangerous to the construction and structure of the chimney if left untreated for too long.
Another reason that chimney shoulders can take the brunt of rain and snow damage is because of where they’re located. When it comes to chimney repair, Alexander and Xavier Masonry can help!
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You’ll notice that along with have sloped ledges that can allow rain to sit and collect, wind-driven rain can also force its way into the corner of the chimney where it meets the wall.
Rain can stay for a surprisingly long time, which is why it’s crucial that when the chimney was installed, waterproofing your chimney should be done to ensure safety from these environmental hazards and damages.
The Problems with Traditional Shoulder Construction
While the chimney shoulder provides a nice visual and structural gradient for the entire chimney, traditional methods of construction were incorrect. Most notably, it is hard to flash the chimney shoulder with the ledges and gradients.
This means that most builders might not have waterproofed it fully against the side of the house, which means that chimney leaks have the potential to seep through.
In addition, the stair steps of the chimney are the perfect resting places for snow, rain, frost, ice, and any type of liquid that you generally want away from the chimney.
Back then, they didn’t really have a quick and easy way to protect the chimney shoulder, but masonry chimney repair nowadays can either build a new chimney shoulder that is safe from rain, or they can repair your existing one and modernize it.
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The Damaged Chimney Crown Repair and Replacement Process
The chimney crown is the top element of a masonry chimney. It’s also known as a “chimney wash” too. Regardless of how it’s known, this piece covers and seals the top of a chimney from the flue liner. Ideally, the chimney crown will have a downward slope to direct water from the flue to the edge of the chimney crown. This helps to prevent erosion of the mortar and brick in the vertical surfaces of the chimney itself.
To know more about blockage of chimney flue check out our article.
When first built, many chimneys have an inadequate crown. This is because some builders will cut corners to save costs, using a common mortar mix that cracks, chips, and deteriorates from weather exposure alone. The crown should be constructed with a Portland cement-based mix that is cast and/or formed with a minimum two-inch overhang beyond all sides of the chimney.
You might need a chimney weather protection, to keep your chimney from deterioration due to weather changes.
Treatments to Avoid Chimney Shoulder Leaks
Most notably, a concrete cap along the shoulder edge is used to protect the area between the siding and the chimney from water. This basically keeps water from ever reaching the surface of the chimney shoulder or the siding with a thick cap of concrete running along the entire edge.
This is the ideal way to protect the chimney shoulder but is easiest to do while the chimney itself is still being constructed.
Another construction-phase treatment that builders might employ is using a smooth-brick closure for the slopes of the chimney shoulder. These bricks are placed in a way that they are more like tiles on the slopes of the shoulder rather than rain-keeping ledges.
This allows water to run off of them without much issue and over time can hold up tremendously. Again, this is something that happens during the construction of the chimney, so it’s not always a possible fix.
If that’s not the case, there are still other treatments to protect the chimney shoulder. For example, one could apply a wash to the area that could help to deflect water from the area. This can prevent further damage, and if the chimney shoulder isn’t damaged yet, this is a great fix to keep it that way.
Another treatment option is using a piece of pre-cast concrete or cut stone. A mason can use this piece to install it around the chimney shoulder to provide a smooth surface that water can run directly off of rather than sitting and collecting over time.
You might see other approaches using concrete as well where a mason might create slopes in between the steps for one gradual slope that water can drain from. Whatever the method, the goal remains the same: to keep water from sitting and collection to avoid water penetration.
The shoulders of a chimney might not seem like more than an in-between for two different sizes, but they serve an important purpose and require a level of care If you find that your chimney shoulders are damaged, get in touch with our chimney repair services and we’ll come and take a look.