Can House Movement Cause Cracks?
Every building experiences movement, and as a result, cracks develop at some point. Many home owners are not aware of these movements and the resulting cracks that appear on their property.
It can come as a shock when a building inspection is carried out and the report indicates that cracks are present in the property. This article will discuss the common causes of these house movements, how they lead to cracks and what can be done to manage them.
What Are The Causes Of House Movements?
Settlement is the downward movement in buildings caused by the weight of the structure and its various elements. It’s one of the leading causes of movement in houses, and it’s generally limited by nature.
Settlement does not pose any threat to the structural integrity of the building. It’s common to witness this after the building has been completed, when an extension is added, or the individual elements find a point of equilibrium, after which movements stop.
Degradation of building materials
Nothing lasts forever and building materials are no exception. Gravity, weathering or poor maintenance can all take their toll on a material’s structural integrity causing it to be undermined by gravity which may cause cracks.
Houses built close to trees
Trees take moisture from the soil around them. Whenever there is a shortage of moisture in the soil where the tree is planted, the roots of the trees spread out to soils beyond their immediate environment.
It’s common to see cracks in houses built on shrinkable clay soil near the trees. When the roots of trees take up moisture, drying and shrinking of the clay soil below the soil foundation happens. Swelling of the clay can also cause damage commonly known as heave.
Cracking can also occur in circumstances where your property or part of it (e.g., an extension) was poorly designed and constructed. Too much weight on a load-bearing wall could contribute to the emergence of cracks, while inferior materials contribute to faulty structural elements that are under-engineered, and thus, do not meet stability requirements.
Subsidence can be explained as the downward movement of the ground caused mainly by the drying out of the clay subsoil. This happens when the ground beneath the building compacts or subsides, although this doesn’t always occur. After subsidence occurs, part of a building, due to unequal movement, exerts stress on the entire structure, leading to the formation of visible cracks.
Peat subsoils will compact under a building load as the moisture is squeezed out, allowing the structure to settle. Unlike clay-based soils, which expand in wet periods and can cause problems with settlements or foundation settles, peats are not prone to this problem because they do not hold much water.
Defective lintels cause problems in the brickwork. Fracturing can occur in houses where replacement windows, usually PVCu, have been installed. This affects particularly bay windows more than other types of windows.
In some cases, lintels over openings are inadequate or missing altogether. This can lead to severe fractures, which adversely affect the operation of windows and doors. Soldier courses were often built with mild steel rods passing through for support, and often, these corrode and fail causing less stable footing. The solution is to cut out the affected areas and replace them with a modern lintel.
Anything that changes the distribution of an object’s weight, such as adding extensions or new openings to a building, will cause cracks at its ends. This usually happens because these structural changes cause uneven distribution of loads, which alters the equilibrium of the forces keeping the structure stable.
Building house on clay
There is clay everywhere in Australia and when it dries out, shrinkage occurs, causing a building to settle. This phenomenon is common during dry weather periods, which is also when trees also take in more water, and physical changes in drainage swells.
When clay rehydrates, it can lead to heave after swelling, affecting the structural strength of the building by lifting the foundation. This happens after a dry spell when the weather changes to a wet period. the action of frost swelling by freezing and the expansion of the moisture content or the removal of trees causes water content to rise and the roots no longer take up moisture.
Why Does House Movement Cause Cracks?
Cracks are a sign that something is wrong with the building. They can happen as an external attack on it or due to chemical changes within its materials, which may lead to even bigger problems in the future.
Cracking and house movement can be structurally dangerous. Differential movements throughout a building may result from poor design, ageing, or changing environmental conditions to which wooden buildings cannot adapt without cracking.
Cracks are typically found at the weakest points of a building, usually around doors and windows or where the floor meets the roof. These cracks may widen over time due to repetitive movement as a result of an unstable foundation.
How Do I Fix Cracks On My Building?
When it comes to cracks in your home, there are two types that you need to be aware of. Severe structural damage needs expert help, but minor repairs such as hairline or fine cracks on surfaces can be fixed using the following techniques:
Cracks in the walls can be repaired with crack stitching, which is a permanent and inexpensive solution. It involves embedding stainless steel bars into slots cut along building joints to restore structural integrity while also ensuring continued reinforcement of these areas during movement.
The type and size of crack you need to fix will determine how much work is required for its repair. If it’s happening with load-bearing buildings or structures, this could mean doing some heavy lifting.
You must widen the crack slightly to be able to insert grout. This will help “sew up” your wall and ensure a natural finish once dry. Push it in as far as possible, then make sure it’s flush or level with the rest of the surface for best results.
For cracks larger than a hairline’s width, you can fill them with polyurethane or latex concrete caulk. Use the caulking gun to force this into place along its entire length so that it holds even during extreme changes in weather conditions.
Larger cracks may need foam-backer rods in addition to caulking. These mono foil metal strips are used for filling gaps and maintaining a good sealant level but can also reduce the amount that needs to be applied or the depth of the sealants in the cracks or gaps.
Carbon fibre straps
To fix bowing or bulging walls that ultimately develop cracks, carbon fibre straps can be bonded to the wall to increase its strength. This will stabilize and reinforce the wall.
This is the type of cement that sets quickly and hardens with the addition of water to form a waterproof product. It’s generally used in construction, as it can stop unwanted leaks from occurring over time.
To fill in a crack, push the cement into it using your putty knife and let that dry for an hour or two before adding another layer. Smoothing out any bumps with a trowel will make sure you get level results.
Fill Minor Cracks In Interior Walls And Plasterwork
You should start by clearing the crack and its surrounding area of dust or debris using a small brush, then vacuum it. Polyfilla is made to fill cracks between tiles, so the next step would be to apply it where needed.
Start by spreading some over any open area or pitting that was visible before applying more onto your tool of choice (a flat surface). Apply pressure evenly around every dip/pit while working towards flattening out all edges until you achieve a smooth surface.
Tips To Prevent Building Cracks
Cracks in walls are usually caused by movement. The best way to prevent them from happening again is allowing for slight movements during construction, which will make your building more durable and resilient over time. If you don’t allow for this movement, the chances of cracks happening are very high because the walls are not free to move.
Ensure movement joints or expansion joints are built-in. The most important function that these provide is to prevent cracks when the wall contracts and expands with changes in temperature. The joint width should be about 30% more than the numerical value for distance between joints.
Some other helpful tips that will help you prevent cracks due to house movements include:
- The use of slip planes in construction is a great way to reduce stress on materials.
- It’s essential to carefully consider the design and positioning of movement joints, slip planes or any other surface affecting stability.
- Make sure to seal and protect movement joints on external walls, so water doesn’t get in.
- Ensure that the movement of joints or slip planes is not obstructed by finishes.
- Sometimes you might need to reinforce the masonry above and below an opening with hinges or other joints not to be damaged by movement.
- The masonry under windows can be tricky because it has a uniform, long low design. Pay close attention to those panels when you install your window coverings, making sure they fit correctly so that they don’t cause problems down the line.
Fix Cracks Before They Worsen
Wall cracks are a dangerous and expensive problem to have in your home. If you ignore them, the costs can be greater than what was initially expected; it might result in making the house wholly uninhabitable or. You might be quite surprised to discover that your insurance policy might not cover the costs of repairing cracks or addressing underlying causes.
You could find yourself saddled with additional expenses, such as relocation and renting an alternative property on top of existing mortgage commitments. Fixing wall cracks before they grow into more significant problems will help save you money in the long run, so don’t wait any longer – get crack-free today by calling a building inspection expert for a quick assessment on 13 15 46.