How to Prevent Diagonal Cracks from Damaging Homes?
How can we prevent or stop diagonal cracks in our homes?
This inquiry is probably the most common question that we receive regularly; from homeowners, contractors, and construction companies. But before we jump into the solution, let’s walk you through what exactly is diagonal crack and how it occurs.
What is Diagonal Crack?
Diagonal cracking is an inclined crack beginning at the tension surface of a concrete member. Steep Diagonal cracks appear in concrete foundations due to point loads that exceed the compressive strength of the concrete. This type of failure, known as settlement, can happen due to “volume changes in clay soils due to fluctuation in their water content, increased pressure on a portion of the foundation, or long-term consolidation of compressible clay under the foundation” If the soil under the footing cannot stand the compression force from the weight of the foundation and house/building, then the structure will sink and any adjacent walls that are adequately supported will resist this movement. Thus, giving rise to diagonal cracks in a building.
This diagonal cracks over the years, affects both the internal and external integrity of a building and that is why we often get calls from people on how to stop such cracks. Now that we know, what is Diagonal Crack, let’s walk you through some of the common reasons for diagonal cracks in a building.
How Diagonal Cracks Occur?
Diagonal cracks occur because of a process called home settlement. Home settlement is a phenomenon that occurs when a home starts moving downward and sinking into the soil unevenly. This is called differential settlement, and it’s one of the biggest threats to any structure. Here are the top reasons for home settlement:
Soil that is poorly compacted
When a foundation is built for a home, a builder will sometimes bring in loose soil to fill any depressed or hollow areas. The builder’s job is to compact the soil adequately before the foundation is built. If this doesn’t happen, your home – because it’s very heavy – will cause the soil to compress, almost always unevenly, leading to foundation trouble.
Soil that’s too wet or too soft
Moist soil around your home is a good thing, but soil that’s too wet can cause issues. Heavy rain or floods, plumbing issues, or poor drainage can cause this. If the soil becomes too soft, your home will sink into it.
Shrinking soils or soil that’s too dry
Birbhum is known to go through droughts. If the soil around your home is dry for an extended period, it can shrink away from your foundation. Soil provides support for your foundation, and without it, you could experience home settlement. Tree roots can also cause issues for your home. Tree roots under your foundation can cause dry soil since they require a lot of water.
All these reasons contribute to the occurrence of diagonal cracks in the construction structure. Further, with the majority of West Bengal facing scorching temperatures throughout the year, diagonal cracks have become a common problem for all construction, resulting in regular calls for help.
That is why in this segment of our blog, we bring you two approaches that can help homeowners, contractors, and construction companies to prevent diagonal cracks from damaging a newly constructed building, along with a cure for properties in which diagonal cracks exist.
Approaches to Prevent Diagonal Cracks and Cure for Diagonal Cracks
There are two ways to handle diagonal cracks from damaging a building, they are:
Pre-Construction Process: By using Drilled Concrete Piers
Post-Construction Process: Drilled Concrete Piers with Curing Process
Let’s walk you through what each process is and how they are implemented!
Pre-Construction Process
The pre-construction process to prevent diagonal cracks from damaging a building focuses on a methodology that should be used by homeowners, contractors, and construction companies before constructing a civil structure. The approach includes a constructive method known as drilled concrete piers. Let’s walk you through what drilled concrete piers are and how they can help prevent diagonal cracks!
What is Drilled Concrete Pier?
A Drilled concrete pier is a combination of the drilled shaft, reinforcing steel, and concrete used to construct deep foundation systems. They transfer a structure’s load to the soil or bedrock to adequately support it through the distribution of the load system.
A drilled concrete pier is also known as cast-in-situ piles, cast-in-drilled-hole piles, drilled shafts, and caissons. Drilled concrete piers can be installed in all soil types and hence provides support to a construction structure from sinking into the soil by preventing the process of home settlement, the main reason behind diagonal cracks in a home.
How Drilled Concrete Piers are installed?
The installation of a drilled concrete pier is a 3-stage process:
Excavation: A hole is drilled in the ground and soil is excavated. Usually, an auger drill is used. When the drill is full of soil, it’s lifted up, and the soil is removed. If a belled pier is necessary because the soil is weak, the necessary bell shape will be created using a special tool. Geotechnical engineers determine how deep the hole needs to be.
Support Implementation: Reinforcing steel is added for support
Concrete is poured into the hole: Once the reinforcing steel is in place, the concrete is poured in. To ensure that the concrete is of good quality, it is suggested to develop the concrete using Sturdflex CemMix Gold – an integral waterproofing liquid admixture with water-reducing and corrosion inhibitor properties ideal for concrete manufacturing. Once the concrete is poured in, it takes about a month for the concrete to dry and harden. After that, the pier will be able to resist both vertical and lateral stresses.
By using these drilled concrete piers, the possibility of diagonal cracks development in a structure can be avoided, and hence are the best pre-construction solution that must be used by homeowners, contractors, and construction companies when planning to construct a new civil structure.
Post-Construction Process
In case of diagonal cracks in an already constructed property, the best way to prevent it from expanding includes a combination of drilled concrete pier and cure. As mentioned earlier how drilled concrete piers are implemented – the same process can also be carried out in an already constructed property. However, in order to carry out the process the property should have adequate side space to bore-drill additional reinforced steel into the foundation till it reaches the bedrock. Once this process has been completed pouring concrete made of Sturdflex CemMix Gold should be performed to stop both vertical and lateral stresses.
After implementing the driller concrete piers the curing process should be performed across all the diagonal cracks in a building. This process includes filling the crack’s joints with Sturdflex Acrylic Pro and covering the opening with Sturdflex Epoxy Putty for all cracks below 3 millimeters. On the other hand, the curing process for diagonal cracks above 3 millimeters includes filling the crack’s joints with Sturdflex Acrylic Pro and covering the opening with Sturdflex Polymer Modified Mortar.
However, despite this 2 step process being an ideal model to stop diagonal cracks in an already constructed building, many a time, it is not possible to implement driller concrete piers in an already constructed structure. Hence, in such a situation, it is advisable to repair the cracks using the curing methods highlighted earlier, along with the construction of parapet walls on the opposite side of the existing increased pressure displayed by the side of the building – to create a balanced load distribution, on the soil.
The application of these processes will stop diagonal cracks in a constructed building from increasing over time while eliminating the possibility of the reappearing cracks by a huge margin. However, it is always advisable to use the first process of diagonal crack prevention, in case, if it is not possible, in that case only the second process is advisable for constructed structures. Whereas in the case of pre-constructed structures, drilled concrete pier is a must-use process to avoid diagonal cracks from appearing in the future.
Note N.B
In this blog, we have made an attempt to cover ground on the regular inquiry we receive from homeowners, contractors, and construction companies on how to prevent or stop diagonal cracks. The solution provided is based on the fact that 97% of all diagonal cracks come from soil issues. However, diagonal cracks may also appear because of poor quality concrete, in such cases repairing concrete with proper admixtures; along with the implementation of the curing process is a must to avoid/stop diagonal cracks.
To know more about Diagonal Crack-related solutions, keep buzzing us at Toll-free– 1800 123 1003 & Whatsapp– 8100 55 66 77; we are happy to help you.