How To Repair Cracks In Brick Walls Step-By-Step

Brick walls give a presence of sturdy solid structure. With so many people opting for the “exposed brick” appearance for their homes, some issues are bound to appear. For brick walls, cracks are a prevalent problem. They can make your property vulnerable to water damage and mould, and your home’s structural integrity is being jeopardised.

brick wall on a bedroom

There’s no need to fear, though. In most cases, these cracks can be fixed without any difficulty. This tutorial will teach you how to identify the sort of crack you have, what to do about it, and how to repair it.

Causes of brick cracks

Cracks appear in your wall for a variety of reasons:

1. Soil subsidence

It all starts with the house’s construction. When you start building, soil excavation is carried out in order to lay the foundations of a building. Then, the ground settles over time, and the foundation of the home shifts somewhat. This movement can result in little vertical fissures, which are usually not an issue. Your house can endure more extreme movement depending on the type of soil it is built on, which might cause significant damage. Natural calamities such as earthquakes, floods, and hurricanes can severely destroy your home’s foundation.

2. Seasonal and climate changes

The materials you use to construct your home react to variations in the weather and seasons in various ways. Long periods of drought, or the rainy season, can cause damage to walls and foundations.

If the cracked brick is often exposed to water, it can break due to garden sprinklers, leaking pipes, and blocked gutters.

3. Deterioration of building materials over time

Building materials aren’t indestructible. Weather, gravity, and poor upkeep all have an impact on your structures.

Buildings are susceptible to corrosion, especially if the concrete base is not adequately laid. Foundation fissures expose the steel reinforcement to moisture content, which can lead to rusting and wall cracks.

4. Construction work nearby

If you reside near a building site, your wall may be affected. Vibration from heavy machinery, excavation, and digging, among other things, can cause your wall to break. 

5. Reactive soils

Clay, for example, is a reactive soil to moisture because it expands when wet and fractures and shrinks when dry. This response might cause your structure to move somewhat, resulting in minor wall cracks if it was built on clay soil. Fortunately, most of these cracks are simply cosmetic and easy to repair. If they are active cracks and larger than 3 mm and continue to grow over time, you should call a structural engineer to check your property.

6. Trees surrounding the wall

Cracks can be caused by large trees growing close to your home. Their root structures are invasive and might cause damage to your home’s foundation. They also require a lot of water, which might have an impact on soil moisture. Dry soil can also create wall fissures.

Types of brick cracks

Every wall contains mortar between the bricks to keep it together. When the mortar breaks, you end up with a wall crack. The thing is that mortar-related issues are prone to escalation over time, resulting in catastrophic structural damage. Consider the following:

Red Clay Cracked Brick Wall Old Texture

1. Horizontal cracks

They are generated by foundation movement and material deterioration impacting the walls. They’re more common in older houses as they have loose materials with not enough elasticity.

2. Vertical cracks

Warmer climates are more likely to see vertical fissures. Their distinguishing feature is the appearance of vertical lines in the mortar and brick, thus splitting the brick in half. Vertical fractures are almost always formed by thermal expansion, which causes the material to shift, resulting in vertical cracks.

3. Brick veneer cracks

They are the zig-zag sort of cracks that run around the perimeter of the bricks, following the mortar line. While this fracture seems to be an easy remedy because it only appears in the mortar, it is typically a symptom of major structural problems.

4. Structural cracks

These types of cracks can cause homeowners significant problems. They are often deep and impact the building’s structural strength, making it unsafe to live in. They arise following an earthquake or as a result of poor construction in the first place.

5. Cosmetic cracks

They are caused by unexpected temperature changes or prolonged exposure to intense heat. They do not usually impact the construction of a building, and a simple fix can do it all. However, keep in mind that if cosmetic cracks are ignored, they can develop into structural cracks over time.

What is crack stitching?

It is a long-term treatment for masonry walls. To restore structural integrity, stainless steel helical rods are embedded into horizontal grooves in the mortar bed joints of your wall. After you’ve found and resolved the underlying issue causing the cracks in your wall, you’ll be able to patch the cracks.

Even if the fractures are small, they should be repaired as soon as possible since water intrusion from leaks or heavy rain can exacerbate the situation. You can start with crack stitching only after the root that caused the cracks has been identified.

Benefits of crack stitching with mortal joints 

Stitching is not difficult. The problem is that many people attempt to repair masonry cracks by simply repointing them without considering that they will most likely shift again, causing the cracks to reappear.

While stitching is more expensive and time-consuming, it is a surefire means of knowing you have supported your brickwork in a way that does not compromise it and will significantly limit the risk of subsequent movement causing more damage. The following are the main advantages of stitching with new mortar joints:

  • Repointing without stitching does not create a structurally sound foundation wall and is a waste of time and money.
  • It’s a long-term structural fix that’s neither invasive nor damaging, and you won’t have to move out while it’s being done.
  • The repair method can be done by anyone. No special skills are necessary. But, before starting, it is a good idea to consult an expert just to ensure that this is a suitable option.
  • The bar distributes the pressures induced by wall movement throughout its whole length, preventing cracks from expanding or new ones from forming. They can achieve this while still allowing for adequate natural mobility in all buildings.

red clay brick wall

How to repair a crack in brick walls by stitching mortar joints

Tools

  • Chasing tool or disc cutter
  • Pointing mortar and trowel
  • Mixing paddle and trowel
  • PPE (Personal protective equipment)
  • Stitching kit, including resin and helical bars 
  • Crack stitching pointing gun and nozzle 

Step 1: Cut out the brickwork joints

Cut off the brickwork joint with a tiny disc-cutter to a depth of around 30-40mm. You will want to buy special discs for this and you can easily find them in your local home improvement store. A plugging chisel can be used if you prefer to do it by hand. It will take more time this way, but it is certainly less expensive. Always cut the joint to a minimum of 500 mm on both sides of the crack.

Remember to take your measurements from the brick face when cutting out and inserting the bars. If your wall happened to be rendered or plastered, you don’t need to specify the thickness of the render/plaster.

2. Clean up

Brush out all of the dust from the cut and then spray down the brickwork, making sure the water is directed into the cut.

3. Mix up cement grout

You are going to need a tub of fixing resin, a paddle to mix the resin in your cordless drill, a pointing gun to apply the resin to the joints, a spare nozzle to use on thinner joints, 10 twisted (or helical spiral) bars measuring 1m in length, and a pointing tool to fully push the resin into the joints.

To make a unique cement-based grout, combine all of the ingredients in a mixing bowl or a cement mixer

4. Fill mortar joints

Fill it halfway with the combined resin and shoot a 10mm thick bead into each joint you have. Once done, don’t forget to clean any excess mortar using a trowel.

5. Insert helical bars 

Push a bar as far as you can into the joint, making sure it is well lodged in the resin.

As you add more helical bars to it, you will have a stronger structural repair and provide more support. You can also use some heavy galvanised iron pieces, such as lintels, to provide even more support to the joint.

6. Apply a bead of resin

To fill the joint, apply another bead of resin over the top of the bar and then firmly secure the bead using a pointing tool. Before re-pointing or plastering, it’s a good idea to snap a photo of the repair channels in the walls so that with future construction work, you can avoid the bars and pinpoint exactly where you put them. It is important that these joints are not accidentally hit or damaged, as this will reintroduce structural issues. You will also be able to track the effectiveness of the work that you have done. 

7. Finish up

Complete the wall. It will either be rendered or pointed over the resin in this case. Basically, you’ll want to stick with one finish line to complement the rest of the wall.

white brick wall on a modern bedroom
There you have it, fearless DIYers! Cracks in your wall can easily be repaired, and so it shouldn’t be a major issue. The important thing is that once you notice any sign of cracks, deal with them immediately as they tend to spread and grow wider over time, so it’s not something you should ignore! Ready for your next DIY project?

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