Why does concrete crack? | How long does it take from concrete to crack? | How to repair concrete cracks? | How to fix concrete driveway cracks? | Is it worth repairing a cracked concrete slab? | Cracked concrete repair cost in Australia | Cracked concrete driveway repair prices
So, you see cracks on your driveway or maybe slabs. What do you do? There are a plethora of companies and products that deal with cracks in concrete. Having cracked concrete on your property can really impact the initial curb appeal.
Repairs are really meant to provide a solution and guarantee that cracks do not reappear in the future. The basis of its article is to assist you in understanding all about concrete cracks, what it takes to repair them, and much more.
Why Does Concrete Crack?
With ideal workmanship and materials, concrete can be a durable, high-strength part of your home. So what would lead to cracks in concrete?
When mixing concrete, a contractor may add excess water to ensure easy installation. However, this leads to a reduction in concrete strength and eventually leads to shrinkage cracks. Concrete cracks may also result from the quick drying of concrete.
If a slab is set, but then the moisture evaporates rapidly, there will be cracking. That is why curing is done with lots of water over a period of time. Other reasons why cracking occurs are pouring concrete over a frozen site or the absence of control joints.
How Long Does It Take from Concrete to Crack?
So, a crack has appeared in your concrete just after installation. Cracks typically can occur before and during concrete hardening. Additionally, it may happen when placing the concrete. Otherwise, cracks can occur after hardening.
Cracking that happen before and during hardening is a result of rapid water evaporation. The evaporation is accelerated by high humidity, wind and temperature.
Concrete cracks mainly occur between 2-3 days after placement. In other cases, hairline cracks may appear on the surface right after the concrete has been installed. Shrinkage cracks caused by air pockets in the concrete can occur within hours of pouring the concrete.
To minimize chances of cracking, immediately after pouring concrete, ensure the following:
- The subgrade is done correctly.
- Provision of joints where needed.
- Avoid adding water to already mixed concrete.
- Concrete cutting to allow for sufficient contraction to avoid shrinkage cracks.
Please note that some concrete cracks may be preplanned. This is done to relieve pressures using joints. However, they should be done the correct way and should be undetectable.
How to Repair Concrete Cracks?
There are several types of concrete cracking. Structural and hairline cracks are the most common in Australia. Other cracks include settlement, shrinkage cracks.
When they appear, it is best to patch them immediately to ensure safety. Specialists repair wide concrete cracks using concrete patching. A patching compound mixed with water is typically used in such cases.
For cracks below a quarter-inch, specialists use concrete seals or a liquid-based concrete crack filler. After using the filler to patch up the crack, painting the surface may be required to mask the new fill. Epoxy injections are also a common method used to repair cracks. Various companies offer epoxy-based products that can repair structural to hairline cracks.
How to Fix Concrete Driveway Cracks?
A reason why homeowners prefer concrete driveways is a high expectation of longevity. However, sometimes, you will be surprised by cracks on the driveway. Some of the issues that cause driveways to crack include:
- Extremely bad weather conditions
- A subgrade that is not sufficiently compacted
- Insufficient concrete mix
Homeowners should consider repairs if the driveway is still structurally sound. To deal with larger cracks calls for resurfacing. This method demands that you use cement-based repair materials to make a concrete crack filler. The steps involved are:
- Use a backer rod to make the crack uniform for the repair work.
- Prepping the cracks – This is done by removing the dirt and removing any growing vegetation. Additionally, you need to use a cleaning solution to wash the crack using a pressure washer thoroughly.
Similarly, using these steps, you can also spread a resurfacer along smaller cracks. In most cases, smaller cracks just need a patch. You can easily purchase materials locally to repair your driveway surfaces.
Is It Worth Repairing a Cracked Concrete Slab?
Cracks in slabs are not too uncommon. If the extent of the damage is not too bad, you could easily repair concrete slabs. For your patio or driveway, you can fix the problem using simple DIY methods.
If the problems are too complex, seek professional expertise. You can use patching material such as filler and concrete caulk. Mix the patching materials with water using a trowel. However, if the damage on the slab is too wide or deep, it will not be worth repairing.
Scenarios that may render your slab irreparable are poor preparation of the subgrade, excessive weight on the slab and compromise of the subgrade via erosion.
Cracked Concrete Repair Cost in Australia
Cracks in concrete need repair before they deteriorate further. The repair cost depends on:
- The number of cracks
- The extent of the crack
- Labour charges
- Site prep activities
- Type of repair materials used
For smaller repairs, you could decide to take the work as a DIY project. This will lower the cost considerably. After assessing the condition of the crack, you can purchase the repair material locally. The solution can cost as low as $10. The success of such projects is highly dependent on the right tools.
Hiring a professional contractor is always a good idea. However, due to labour charges, expect the cost to be higher. The average cost a contractor will charge starts from $3 per square feet. Therefore, the larger the area for repair, the higher the cost.
Cracked Concrete Driveway Repair Prices
The cost of repairing a concrete driveway depends on the extent of damage and labour charges. To fix cracks, contractors have to assess the damage on the driveway surface. They typically charge based on the area of repair in metres squared.
The average cost in Australia for repair is $3/m2-$8/m2. The materials mostly used sealant and mixed patching compounds—mandatory tools to have to include a trowel and a foam backer rod.