Repairing Guides

how to repair brick chimney mortar

by Vallie Pagac Published 1 year ago Updated 1 year ago

How to Repair Mortar in a Brick Wall or Chimney

  1. Prep the Surface. Widen the crack to ¼ inch with a chisel and hammer and remove any damaged concrete. ...
  2. Apply Sealant. Cut the nozzle tip of Quikrete Advanced Polymer Mortar Joint Sealant at an angle. Make sure the opening matches the width of the crack.
  3. Finish. Drag a trowel over the mortar joint immediately after placement to remove excess material and match the surrounding surface.
  4. Let Dry. It doesn’t take much time for the surface to dry. The area should be tack-free in about two hours, depending on temperature, humidity and joint depth.

Part of a video titled Mortar Repair, 1 Hour - Easy Tuckpointing, Repointing Caulk ...
This job start-to-finish should take you at most an hour to prep get everything set up put itMoreThis job start-to-finish should take you at most an hour to prep get everything set up put it together and clean it quikrete makes a product.

Full Answer

How to repair a damaged brick chimney?

Replacing Damaged Bricks

  1. Measure the length of the damaged irregular bricks in the chimney. Bricks that have been custom-cut will require you to cut the new brick to fit.
  2. Mark the measurement of the old bricks on your new brick using a marker.
  3. Put on safety goggles and work gloves. ...

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How to cement over a brick chimney?

You Don’t Have to Spend a Fortune on a Stunning Concrete Fireplace—We Did It for $215

  1. Gather Your Supplies. Even though the Pollios were covering a large surface area, their supplies were fairly limited. ...
  2. Install the Durock and Corner Bead. Because the Pollios didn’t have existing drywall or a mantel to work around, they went straight for the Durock—cement boards that are ...
  3. Apply the Ardex to the Joints. ...
  4. Skim Coat the Entire Surface. ...

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How to remove mortar before repointing brick?

  • Chisel – A tool with a shaped cutting edge of the blade on its end that is used for carving or cut pointing the old mortar.
  • Cement mixer – Is used to mix the required materials for filling the gaps.
  • Pointing trowel – It is a small hand tool with a handle and flat metal blade that is used for scooping or spreading the mortar.

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How to repaint brick chimney?

Tools for Painting a Brick Fireplace

  • Wire brushes
  • Wet-dry vacuum
  • Sponge
  • Respirator
  • Rubber gloves
  • Safety glasses
  • 3 or 5-gallon bucket
  • 2-inch paintbrush (angled and stiff is best for this application)
  • Paint roller
  • Two ¾-inch nap roller covers

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What is the best mortar for chimney repair?

Repointing a chimney does not require a great deal of mortar. QUIKRETE® Mortar Mix or Mason Mix is available in bags conveniently sized to provide just enough mortar for the present job or to have a little left over for other small jobs. QUIKRETE® Vinyl Concrete Patcher can be used instead for better adhesion.

How do you fix crumbling chimney mortar?

0:232:01Repair of chimney mortar joints. - YouTubeYouTubeStart of suggested clipEnd of suggested clipCome across horizontally and just start to work my way across the grid work of mortar joints thatMoreCome across horizontally and just start to work my way across the grid work of mortar joints that have been ground out and prepared for tuckpointing. And then this mortar will set up.

How do you fix crumbling mortar between bricks?

0:383:46How to repoint mortar joints - YouTubeYouTubeStart of suggested clipEnd of suggested clipKnock up and water mix with plasticizer to make sure it bonds into the joints adding a little bit ofMoreKnock up and water mix with plasticizer to make sure it bonds into the joints adding a little bit of water at a time don't make it too wet or running otherwise.

How do you repair brick fireplace mortar?

1:021:49Repairing Fireplace Mortar - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd work that mortar into the joint there. And smooth it out. And then you can always come back withMoreAnd work that mortar into the joint there. And smooth it out. And then you can always come back with a wet rag. And kind of smooth out the edges if you need to make a nice little mortar joint.

What is the difference between tuckpointing and repointing?

Repointing is the process of removing damaged mortar joints and renewing them. Tuckpointing is quite similar but is not always completed for damage control. Tuckpointing by definition is a style that uses two different colors of mortar to alter the appearance of mortar joints, this is an important distinction.

How much does it cost to re mortar a chimney?

Repairing brick chimneys costs $175 to $1,000 on average. More extensive damage could run upwards of $4,000 and a total chimney replacement is about $10,000....Brick Chimney Repair Cost.RepairCost to FixCracked Bricks (less than 10 bricks)$175 - $500Cracked Bricks (more than 10 bricks)$750 - $1,5002 more rows•Jan 18, 2022

Will new mortar stick to old mortar?

Concrete, mortar or similar materials are not designed to stick or bond to old surfaces. You will not get any satisfactory results if you simply add new mortar to old. It just doesn't work. Using a modified thinset mortar would be the preferred method for this type of installation.

How do you repoint a brick chimney?

9:2913:06How to Point a Brickwork Wall or Repoint a Chimney - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd then around the corner for about 50 millimetres. Also don't forget to make sure the mortar isMoreAnd then around the corner for about 50 millimetres. Also don't forget to make sure the mortar is firmly home on both sides. And then I finish by pushing the edge of the mortar home with my finger.

Can I repoint brick myself?

Repointing brickwork involves carefully repacking the mortar sitting between the individual bricks, or stone blocks, that make up the exterior skin of your home. Although many renovators carry our DIY repointing, given the requirement for working at heights it can be a job that is best outsourced to a professional.

Do you need special mortar for fireplaces?

The mortar in most brick joints consists of sand, lime, and portland cement. But in a fireplace, that mix just crumbles away when subjected to roaring wood fires. For this application, masons rely on a refractory mortar made of magnesium silicate, which can withstand heat up to 2,000 degrees F.How to Repoint a Brick Fireplace - This Old House › fireplaces › how-to-repoi... › fireplaces › how-to-repoi...Search for: Do you need special mortar for fireplaces?

Can you use regular mortar in a fireplace?

Domestic Fireplace Mortar is a premixed and ready to use regular mortar. It was developed for installation of firebrick in masonry fireplace installations. It also has many other uses such as in chimneys, boilers, incinerators, furnaces, kilns, etc.Domestic Fireplace Mortar - Heat Stop › products › d... › products › d...Search for: Can you use regular mortar in a fireplace?

What mortar do I use with fire bricks?

RUTLAND Fireplace Mortar is perfect for repairing small chips or cracked firebrick, re-pointing mortar joints between firebricks, and bonding firebricks together. Adheres masonry to masonry for brick, firebrick, and stone. Easy to apply with a caulking gun and will last for years.Fireplace Mortar - The Home Depot › Heating-Venting-Cooling-... › Heating-Venting-Cooling-...Search for: What mortar do I use with fire bricks?

How do you fix mortar around a fireplace?

1:443:07How To Fix Cracked Mortar or Concrete in a Fireplace with Mor-flexxYouTubeStart of suggested clipEnd of suggested clipAnd recess the backer rod three-eighths of an inch to half an inch below the surface cut the nozzleMoreAnd recess the backer rod three-eighths of an inch to half an inch below the surface cut the nozzle to the bead size you need and load the caulking gun gun more flex into the joint.

How long does chimney mortar last?

As a result, chimney liners are incredibly important in making sure you and your family stay safe. Most chimney liners only make it 15 to 20 years, given the amount of abuse they endure.

Why do chimney bricks crumble?

This can happen for several reasons, but the most common reason is the weather. When moisture becomes trapped inside the bricks and then the temperature drops below freezing, the water in the bricks freezes. Since frozen water expands, when those bricks thaw, they become brittle and flake apart.

Why is my chimney crumbling?

One of the biggest reasons for crumbly, damaged chimney masonry is water infiltration. If your chimney has small cracks, water can get in and will freeze and expand when the temperature drops. This will lead to further damage and start a cycle that can eventually cause major structural and safety issues.

What is chimney mortar?

Chimney mortar is the material made for sealing between bricks, stone and concrete. It also prevents water from entering into home through cracks i...

How can I tell if my chimney mortar is in need of repair?

One way to tell if you need to repair your chimney mortar is by looking for cracks in the masonry work. If you see any cracks, that means the morta...

How do I seal my chimney?

You can use pre-mixed, high strength mortars available at the hardware store. You can also use mortar mix which you will have to purchase separatel...

What is efflorescence?

Effloresce is a deposit of salts and minerals which appear as white crust on the chimney masonry due to water damage.

How do I repair mortar?

To repair mortar, you will need to remove all loose material with a brush or chisel. Then, use a trowel to apply fresh mortar and press it into the...

What is chimney crown?

A chimney crown helps divert rainwater away from your home by creating an overhang above the top of your chimney. A properly installed crown helps...

What is a clay flue liner?

Clay flue liners are installed inside the chimney as an alternative to metal, which rusts over time. They help keep moisture out of your home by pr...

What is Mortar and Why Do You Need It?

Mortar is the mixture of sand, water and cement that holds bricks together. It allows us to build structures such as brick chimneys, masonry walls or walkways at home without them falling apart right away.

How to Repair Mortar (Step by Step)?

Mortar is the most important part of masonry work. Poor quality mortar or unwanted cracks in mortar will lead to major damage on your chimney if not repaired properly on time. Even you can see some deterioration, it should be fixed as soon as possible for better result and safety purposes.

Proper Removal of Old Mortar

The first step in repairing chimney mortar is to remove the old mortar. This can be accomplished with a hammer and chisel or, better yet, an angle grinder outfitted with a masonry blade. Most types of siding will tear away when struck by one (just make sure you are wearing eye protection).

Cleaning the Chimney before Repointing Begins

Cleaning the chimney is an important step in any repointing project. It helps remove soot, grease, and other debris that can interfere with the new mortar’s ability to bond properly. There are a number of ways to clean a chimney, but the most common is to use a Chimney Sweep Brush.

The Tools Required for a Successful Pointing Job

There are a few key tools that you will need in order to complete a successful pointing job on your chimney. These include: trowel, hawk, margin trowel, and bucket. You can find most of these at your local hardware store or home improvement center. Be sure to pick up some mortar mix while you’re there, too!

Tuckpointing Techniques

Tuckpointing is a technique where the mortar between bricks and stones are being repaired. This can be done in several ways, depending on whether you have new or old brickwork at your disposal.

Environmental Protection and Safety

Chimneys are found in every household and therefore, the importance of maintaining them cannot be undermined. However, what most people do not realize is that there is more to building a fire than just lighting it up.

What is a Chimney Brick?

A chimney brick is a type of masonry unit that makes up the interior structure and exterior walls of a traditional fire place. These bricks are made out of clay, sand and straw which gives them their distinctive yellowish orange color when they’re fired in a kiln at high temperatures.

Types of Chimney Bricks

Different types of bricks have different properties in the chimney. The bricks are divided into two main categories, standard and refractory. Standard brick is made for normal use because it does not withstand high temperatures well compared to other materials used in a fireplace or stove lining.

How to identify the problem with your Chimney Bricks?

Your Chimney Bricks may be damaged because of weather changes or heat exposure. The bricks lose their flexibility and crack easily under stress or weight. This is a common problem that can affect the structure of your house over time if you don’t take care of it immediately.

Why are my Chimney Bricks Crumbling or Loose?

One of the most common reasons for your brick to be crumbling or loose is because it’s old. Chimneys are typically built with bricks and mortar, so over time those bricks can begin to crack and crumble as they break down.

Types of Mortar for repairing Chimneys

There are many types of mortar that can be used for repairing a chimney. The most popular type is called Portland cement mortar, which is made from portland cement, sand, and water. It is durable and weather-resistant, making it the perfect choice for repairing a chimney.

Tools you will need for a Chimney Bricks repair

A bucket of cold water, protective gloves and glasses are the tools you will need for a Chimney Bricks repair. Make sure to also check your local building codes before beginning work. It is not uncommon for homeowners in many different parts of the country to be required by law to stop or fill up any holes that could pose safety hazards.

How to repair a Chimney Bricks Step by Step?

It is possible that you are facing some problems with the bricks of your chimney because it has been built many decades ago. There might be cracks in the mortar and therefore, water may get inside leaking to other parts of house which can lead to serious consequences. Here we will discuss how first step should be taken:

Why are brick chimneys durable?

Brick homes and chimneys are durable and built to last thanks to mortar joints that take the brunt of damage caused by wall movement, foundation settlement and exposure to elements. A buffer between the bricks, mortar joints are designed to crack and deteriorate before the brick when faced with movement and other stressful pressure.

How long does it take for a concrete slab to dry?

Let Dry. It doesn’t take much time for the surface to dry. The area should be tack-free in about two hours, depending on temperature, humidity and joint depth. For wider, deeper and longer cracks, you should consider making the repairs with traditional mortar.

Can you apply mortar joint sealant in 50 degrees?

Otherwise, a small problem today could become a major headache — and expense — in the future. • Mortar joint sealant is temperature sensitive; don’t apply in temperatures under 50 degrees Fahrenheit. • Work in a ventilated area, and wear safety glasses and waterproof gloves.

How long does it take for mortar to dry before lighting a fire?

Leave the mortar to dry for 24 hours before lighting your fire. The mortar can take up to 1 days to properly bond with bricks. Lighting a fire can compromise the structural integrity of the chimney so use your electric heater for the next 24 hours while the mortar dries.

How to get mortar out of mortar pile?

Squeeze the mortar into the gaps between the bricks. Wrap your dominant hand around the bag at the top point of the mortal pile. Use your other hand to guide the nozzle. Squeeze your dominant hand, at the top of the bag, to push the mortar out the nozzle.

How to mix cement and sand?

Slowly turn the bucket as you are mixing to help agitate the sand and cement. To make 1 bucket of mortar mixture, use 3 heaped trowels of sand and 1 heaped trowel of cement powder. This ratio applies to volume rather than weight.

How to make a mortar and sand?

Mix the sand, cement, and water together. Turn the sand, cement, and water using a bricklayers trowel. Slowly turn the bucket as you mix the mortar, this will help to further mix the ingredients. Keep mixing until the mortar is well combined. Ideally the mortar should be the consistency of porridge.

How to make mortar consistency?

Ideally the mortar should be the consistency of porridge. If the mortar is too thick, add a little bit more water until it is the right consistency. Keep the mixture thick enough so that it can stick to the trowel. Scrape any sand or cement from the sides of the buckets into the mixture.

How to smooth out mortar?

Use a striker to smooth out the mortar. A strike is a curved scalper that will smooth out the mortar and help to push out any air bubbles. Hold the striker in your dominant hand and pull the head over the areas that you have applied the mortar on. Start with the horizontal lines and then complete the vertical lines.

Can you fix a chimney that is collapsing?

Keep in mind that fixing the mortar on a chimney that is collapsing will not fix the chimney. You will need to hire a brick mason or engineer if there are missing bricks, severe cracks in the bricks, or if the chimney is leaning.


There are those that are very easy to repair, such as replacing a few bricks. These are not very expensive and can be done quickly.


As you know, the exterior of the chimney is exposed to weather and other elements all along its lifetime. Hence, it is quite normal that the mortar will get damaged over time, form cracks, and even wither out in forms of chunks. When such a situation arises, you will definitely have to re-point it as soon as possible.


Now, flashing is what keeps water from seeping in at the point where your chimney enters the roof. While one of its ends is tucked under shingles, the other is mashed into bricks. Water seeps inside the chimney if any damage is done to it or it pulls away.

How to make a brick mortar?

Mix the Mortar. Mist the brick again. Then, following the directions on the bag, stir water into the dry mix until it reaches the consistency of peanut butter and clings to an upended trowel. Wait until a film of water forms on the mix, about 15 minutes. Stir the water back in.

How to keep mortar from drying out?

When the mortar is firm to the touch, brush diagonally across it to remove any dry mortar crumbs. (Brushing in line with the joints can pull out the fresh mortar.) Then carefully sponge mortar residue off the brick faces. For the next three days, use a tarp to protect the soft joints from the sun, wind, or hard rain, and give the wall a daily misting to keep the brick and mortar moist.

Who wrote the poem "Brickwork is just so much rubble without a bed of mortar to seal and hold

By Danny Palousek. Even the most beautiful brickwork is just so much rubble without a bed of mortar to seal and hold it together.

What is hydraulic lime?

You can choose between hydraulic lime, which comes in bags and hardens when it reacts with water, much like portland cement, and lime putty mortar, which comes in buckets and slowly hardens by reacting with carbon dioxide in the air.

How Do You Fix Cracked Chimney Mortar?

The mortar around your chimney isn’t just decorative. It acts as a support system for the bricks and it seals the edges for maximum protection. Unfortunately, mortar wears down much faster than bricks do. Thus it has to be replaced every so often. The guide below explains how we fix cracked chimney mortar so you know what to expect moving forward.

The Average Lifespan of Chimney Mortar

Bricks can last 100 years or more, but mortar is likely to last about 25 years. If you purchase an older home with a brick chimney, chances are its mortar is past its prime. Chimneys are susceptible to more damage than siding and other brick structures because they are not covered by roofing.

Get Routine Chimney Inspections to Catch Issues Early on

If you can catch mortar cracks early on, your repair costs will go down tremendously. This also ensures that you address problems at the first signs, before they have widespread impact. We recommend scheduling routine chimney inspections, along with brick siding inspections. Complete necessary repairs as they arise to protect your property.

How to clean mortar off brick?

Scrub the mortar off the bricks with a stiff brush. This also knocks down and smooths out any high spots along the joint edges. Once the joints have set up (about 30 minutes after tooling), use a stiff-bristle brush to clean dried mortar off the bricks ( Photo 9 ).

Why do brick chimneys need to be cut out?

Crumbling mortar in brick walls and chimneys has to be cut out and replaced to avoid structural and water damage. Tuckpointing—cleaning out and remortaring the joints—is easier than it looks if you have the right tools.

How to pack mortar into joints?

Work the mortar into the joint with your tuck pointer. Pack the joint full before moving on to the next one. Use a brick trowel and a tuck pointer to pack the mortar into the joints. Most pros prefer this method to using a grout/mortar bag.

How long does it take for mortar to harden?

But don’t let the mortar get too stiff—it can start to harden after just 30 minutes, making it difficult to tool the joints. If you want rounded joints, press a masonry jointer into the top of vertical joints and pull the tool downward. The jointer will push out some of the mortar and leave a concave shape.

How long does it take to put mortar in a joint?

Finish one joint before moving on to the next. Let the mortar in the filled joints set for about 30 minutes.

How to make peanut butter mortar?

Mix the mortar to the consistency of peanut butter with no dry spots or clumps. You’ll know the mix is right when it sticks to your trowel when you hold it at a 45-degree angle. Let the mortar sit for 10 minutes before using it.

How long does it take to tuckpoint a wall?

You’ll hone your skills and get a good idea of how much you can tuckpoint at one time. You’ll have 30 to 60 minutes of working time once you mix the mortar. Get ready for the dust.

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