Chimney mortar needs to be replaced in the Chicagoland area because repeated freeze and thaw cycles, weather elements and age break down the joints between bricks long before the brick itself wears out. Chimney tuckpointing removes the deteriorated and missing mortar and is replaced with new mortar, sealing out water and protecting your chimney.
As you may have heard, the El Nino weather patterns states that the Midwest will have a milder winter. Although you might be breathing a sigh of relief, that predication does come with a cold-free, snow-free winter. What lesser snow means? With Chicago, we never know. This means you still need to prepare for the winter season and you can rely on Superior Chimney protecting your chimneys home for the long term.
What is Chimney Tuckpointing?
Chimney tuckpointing is the trade term for grinding out failing mortar between stone or brick and replacing it with fresh mortar that closely matches the existing mortar. Tooling is used in each joint to the shape you see today. The reason chimney tuckpointing is so important is so the surface keeps the water out and directs it away from the chimney and inside your home.
Why Does Chimney Mortar Need to be Replaced?
The brick on most Chicagoland homes can last well over a hundred years. The mortar holding those bricks together wears out much sooner and usually needs attention decades before the brick does.
That difference is by design. Mortar is meant to be the softer, sacrificial part of the wall, wearing down so the brick can stay intact. Replacing mortar is far simpler and less costly than replacing brick.
Once the joints start breaking down, water finds its way behind the brick. That is when small problems start turning into expensive ones.
What Causes Chimney Mortar to Deteriorate and Crumble?
Chimney mortar crumbles due to it being porous. When it rains or snows, water is absorbed into the joints. Then when the yearly freeze thaw cycle returns, it pries the chimney mortar apart a little more each time. Long winters with frequent swings above and below freezing repeat that damage over and over each season.
Lake Michigan Wind and Driving Rain
Wind coming off Lake Michigan pushes rain sideways into the face of the brick. Chimney walls soak up even more water, then when temperatures drop, it gives the freeze and thaw cycle more to work with.
Why Chimneys Fail First
A chimney stands exposed on every side above the roof. It takes on rain, snow and wind from all directions. But don’t forget the debris and our neighborhood critters which find shelter inside the chimney. The combination is why chimney mortar tends to fail ahead of the rest of the house.
What Kind of Mortar Is Used for Tuckpointing?
The right mortar for tuckpointing matches the strength, color, and texture of the original. Soft historic brick needs a softer lime blend, while modern hard brick can take a stronger cement blend.
Matching Mortar to Historic Chicagoland Brick
Many vintage bungalows and two flats from Oak Park to Evanston were built with common brick, a softer brick fired from local clay. These walls need a lime rich mortar so the joint flexes and protects the brick face.
The National Park Service makes the same point in Preservation Brief 2, its guide to repointing mortar joints in historic masonry. New mortar should be softer than the surrounding brick so the joint absorbs the stress.
Mortar that is too hard traps moisture and forces the brick to take the strain. Over time that leads to cracked and flaking brick faces.
Color Matching for a Uniform Look
Superior Chimney works to match the chimney mortar to the current color for a uniform look. But it goes one step beyond just the color. We also work to ensure that the joint profile and tooling style also match to the original as closely as possible.
Done correctly by an experienced masonry, it will appear as one continuous chimney wall.
Chart 1. Matching Mortar to Your Brick
Brick Type
Typical Chicagoland Homes
Recommended Mortar
Soft historic brick
Vintage bungalows, two flats, and older homes built with Chicago common brick
Softer lime blend that flexes with the brick and protects the brick face
Modern hard brick
Newer construction and suburban homes built in recent decades
Harder Portland cement blend for strength and durability
Chimney masonry
Every home with a masonry chimney
Blend matched to the original brick, color matched and tooled for a tight, water resistant joint
Steps to a Chimney Tuckpointing Process
A tuckpointing professional understands each step of the process intimately. Their ability to make chimney tuckpointing a work of art is what makes the repair last.
Chart 2. The Chimney Tuckpointing Process Step by Step
Step
What Happens
Why It Matters
1. Inspect
The crew checks every joint to see how deep the damage goes
Sets the scope and the right mortar for the job
2. Remove
Failing mortar is ground or raked out to sound material
Gives fresh mortar a solid base to grip
3. Prepare
Joints are brushed clean and maybe lightly misted with water
Keeps old masonry from pulling moisture out of new mortar
4. Insert
Fresh, color matched mortar is pressed into the joint in layers
Fills the joint completely for a strong bond
5. Tool
Joints are shaped to match the original profile
Sheds water and blends with the existing wall
6. Clean and Cure
Excess mortar is cleaned off and the work is left to cure
Leaves a tight, uniform, water resistant finish
Chimney Tuckpointing and Repairs
Chimney tuckpointing restores the mortar joints between chimney bricks to stop water intrusion, prevent structural compromise, and bring back the strength and appearance of the chimney.
Superior Chimney’s masonry crews have the experience and on-going training to continuously perfect their craft. Younger crew members work years with the experienced members to learn and perfect each step of the process. Ask one of our crew members the preparation steps taken before each project. It certainly is a work of art.
Chimney Crown and Flashing
We discussed the brick and mortar that comprises the bulk of the chimney, but what about the chimney crown and flashing? The chimney crown is the concrete cap or slab that covers the top of the chimney. It is the first line of defense against rain and melting snow. Cracks in the crown send water straight down into the brick and mortar below.
A chimney repair looks at all elements of the chimney including the chimney crown, flashing where the chimney meets the roof, and every mortar joint in between. Sealing all three together gives your chimney the best protection.
What Happens When Chimney Mortar Repairs Aren’t Done?
When chimney mortar repairs are delayed, water reaches the brick, the components behind it, and sometimes the inside of the home. Small cracks grow larger which can cause the bricks to loosen and fall out. If the chimney is still left to deteriorate, the chimney may start to get the leaners. This is how you know the integrity of the chimney has been compromised. To that end, you can expect water to enter your home and begin to show water damage in your home.
A chimney that could have been saved with tuckpointing may eventually need a partial or full rebuild. That is a much larger and costlier project.
Addressing worn joints early keeps the repair simple and the costs…down.
How Do You Know If Your Brick Needs Tuckpointing?
Your brick needs tuckpointing if the mortar scratches away with a key, sand collects at the base of the wall, white powdery stains appear, or you can see gaps or cracks where mortar use to be.
The best time to check is spring once the snow melts or fall right before the harsh winter season. Walk around the house and look up. If you see joints missing, it’s time to call Superior Chimney for an inspection.
Chart 3. Warning Signs Your Mortar Needs Attention
What You See
What It Means
Recommended Step
Mortar scratches away easily with a key
Joints have softened from repeated freezing and thawing
Schedule a tuckpointing evaluation
Sand or grit collecting at the base of walls
Mortar is actively breaking down and washing out
Repoint the affected joints soon
White powdery stains on the brick
Water is moving through the masonry and leaving salts behind
Find the water source and repoint, then clean
Visible gaps or missing mortar
Water has a direct path behind the brick
Tuckpoint promptly to protect the wall
Flaking or chipped brick faces
Trapped moisture is freezing inside the brick
Replace damaged brick and waterproof
Cold drafts or water stains near the fireplace
Chimney mortar or crown may be letting water in
Book a chimney inspection
What to Watch for by Season
Scheduling repairs in late spring or summer gives new joints a full season to cure before the first hard freeze. Booking chimney work before fall means the fireplace is ready when the weather turns cold.
Chart 4. Chicagoland Seasonal Masonry Calendar
Season
What To Do
Spring
Inspect walls and the chimney for winter damage and schedule repairs
Summer
Ideal curing weather for tuckpointing, chimney repairs, and rebuilds
Early Fall
Finish repairs, apply waterproofing, and book a chimney inspection before burning season
Winter
Watch for leaks, drafts, and ice buildup, and plan spring work
Preventative Maintenance with Chimney Saver
Masonry chimney repair and fireplace repair costs can be minimized with regular inspections and preventative maintenance. Waterproofing is one of the most effective steps you can take.
Superior Chimney can apply Chimney Saver, a waterproofing agent developed specifically for masonry chimneys. It helps preserve the chimney and reduce brick repairs.
The formula is vapor permeable, so it lets your chimney breathe out while keeping water from coming in. Moisture already inside the masonry can escape, while outside water stays out.
You can read more about how Chimney Saver protects against brick chimney repairs and fireplace repairs.