Self-Leveling Concrete: Repairing Your Patio Like A Pro

Self-levelling concrete is a great way to repair uneven concrete slabs or surfaces. It is a cementitious mixture that is similar to concrete but flows more easily and sets up much faster. When mixed with water, it can be poured over existing concrete slabs, where it will spread and level itself out, creating an even surface texture. Self-levelling concrete can be used as an underlayment for tile, carpet, or other floor coverings. It is a cost-effective solution to repair, smooth, or raise a floor.

Clean the surface

To repair a concrete patio using self-levelling concrete, the first step is always to clean the surface. This is important because it ensures that no dirt gets inside the new concrete mix.

First, remove any furniture, grills, or planters from the patio so that the entire surface is visible. Sweep away loose dirt, debris, or leaves. Cover any nearby plants or landscaping with a tarp for protection.

Next, you will need to address any stains. Water stains, mould, and mildew can be removed using a garden hose or pressure washer. If this doesn't work, mix a solution of 3/4 cup bleach and 1 gallon of water. Wearing protective gear, including rubber gloves, scrub the area with a brush. Rinse thoroughly with clean water and ensure the patio is fully dry before continuing.

Grease and oil stains can be treated by sprinkling sawdust, cornstarch, or baking soda on the stain to absorb any spills. You can also mix baking soda with a little water to create a cleaning paste. Scrub it gently into the stain and let it sit for 30-60 minutes. Then, wash away the solution or sweep away any remaining powder. If the stain is old, it may have penetrated the surface, so try using a degreaser following the manufacturer's instructions.

Rust stains can be removed using white vinegar. Spray it directly onto the stain and let it sit for less than an hour to penetrate deep stains. Scrub with a stiff-bristle brush, rinsing and drying afterward. If the stain doesn't improve, try repeating the process or use a concrete rust remover.

Once you have treated any stains, you can clean the entire patio floor. Create a cleaning solution of warm water and a few drops of dish soap and apply it to the surface. Let it sit for a while, then mop the patio and rinse it with fresh water. Repeat the process as many times as needed. Alternatively, you can use a mixture of vinegar and baking soda or oxygen bleach, following the instructions for each method.

Seal any cracks

Sealing cracks in a concrete patio is a vital step in the repair process, as it prevents the new surface from cracking again. Here are some detailed instructions to help you seal those cracks effectively:

Prepare the Crack for Sealing:

Before you start filling the cracks, it's important to clean them and remove any debris, oil stains, grease, or loose concrete. This step ensures that the sealer adheres properly to the crack. You can use a wire brush or a similar tool to scrub the cracks and their surrounding areas. If there are any large chunks of concrete or protruding debris, you can use a chisel or a similar tool to remove them carefully.

Choose the Right Crack Filler:

The type of crack filler you choose depends on the size of the cracks and the conditions your patio is exposed to. For hairline or small cracks, flexible concrete caulk is a good option. It adheres well to concrete and can flex with the natural expansion and contraction of the material. For wider cracks, you may need to use a backer rod or sand as a filler to support the caulk and reduce the amount needed. Polyurea crack filler and epoxy crack filler are other options, but they usually require more prep work and are often more expensive.

Apply the Crack Filler:

Once you've chosen the appropriate crack filler, it's time to apply it. If using caulk, cut the tip of the tube at a 30-degree angle, making the opening the same size as your crack. Smoothly fill the crack with the caulk, ensuring it's flush with the surface. For wide joints, use the back of an old spoon to smooth the caulk, wiping the spoon with a rag and mineral spirits as needed. If using a backer rod, insert it into the crack with your fingers, setting it about 1/4 inch lower than the surface of the concrete. Then, apply the caulk on top.

Allow the Filler to Cure:

After you've filled the cracks, it's important to let the filler cure completely before moving on to the next step of the patio repair process. The curing time will vary depending on the type of filler used and environmental factors, such as temperature and humidity. Always refer to the manufacturer's instructions for specific curing times.

Clean the Surface Again:

Even if you cleaned the patio before sealing the cracks, it's crucial to clean it again after the filler has cured. This step ensures that no dirt, dust, or grime has accumulated during the curing process, which could interfere with the adhesion of the new concrete layer. Use a brush and soap to give the floor a good scrub.

Sealing the cracks in your concrete patio is a vital step in preparing the surface for self-levelling concrete. By following these steps, you'll create a smooth and durable surface that will enhance the overall appearance and longevity of your patio.

Prepare your tools

To repair your concrete patio using self-levelling concrete, you will need to prepare the following tools:

• A high-quality concrete repair tube to seal the cracks.
• A caulking gun to help apply the sealer.
• A margin trowel to smooth the sealer and primer.
• A high-quality concrete primer.
• A paint roller to apply the primer.
• A mixer drill to mix the water and concrete.
• Self-levelling concrete.

It is important to ensure that you have all the necessary tools and supplies ready before you begin the repair process, as you will have a limited time to work once the self-levelling concrete is poured.

In addition to the tools listed above, you may also need the following materials to prepare your concrete patio for the self-levelling compound:

• A shop vacuum, broom, and mop to clean the surface.
• Mixing buckets or barrels (at least 6 gallons) for mixing the concrete.
• Kraft paper or plastic sheets to protect the surrounding area.
• A gauge rake to spread and distribute the self-levelling concrete evenly.

Prime the patio floor

To repair a concrete patio using self-levelling concrete, priming the patio floor is an essential step. Here's a detailed guide on priming your patio floor:

Clean the Surface

Before priming, ensure your concrete patio is clean and free of any debris, oil stains, grease, or dirt. This step is crucial as any dirt or grime can prevent the primer from adhering properly. Use a brush and soap to give the floor a thorough scrub.

Choose the Right Primer

Not all self-levelling compounds require a primer. Check the instructions of your chosen self-levelling compound to determine if it requires priming. If a primer is recommended, use the one suggested by the manufacturer for optimal results.

Prepare the Concrete

Inspect your concrete patio for any holes or cracks. It is essential to repair and fill these imperfections before priming to prevent the compound from leaking out. Remove any loose debris, chipped concrete, or dried paint, as these can cause the self-levelling concrete to crack or deteriorate.

Apply the Primer

Once your patio is clean and prepared, it's time to apply the primer. Use a high-quality paint roller to ensure even application and quicker coverage of the entire concrete surface. Follow the manufacturer's instructions for drying time before proceeding to the next step.

Check for Even Application

After applying the primer, inspect the patio floor to ensure the primer has been applied evenly. Use your roller to address any areas that may require additional primer. Allow the primer to dry completely before moving on to the next step of your concrete patio repair.

By following these steps, you'll ensure that your concrete patio is properly primed and ready for the application of the self-levelling compound. Remember that priming helps create a strong bond between the concrete and the levelling compound, improving the overall durability of your repaired patio floor.

Pour and smooth the self-levelling concrete

Pouring and smoothing self-levelling concrete is a straightforward process, but it requires careful preparation and attention to detail. Here are some detailed instructions to guide you through the process:

Prepare the Concrete Mix

Before you begin, ensure you have carefully measured the area and calculated the amount of self-levelling concrete required. Self-levelling concrete is typically sold in bags, and the coverage will depend on the thickness of your application. Refer to the manufacturer's instructions for guidance on mixing the correct ratio of water to concrete powder. It is crucial to follow these instructions precisely, including the specified mixing time, to achieve the desired consistency.

Pour the Concrete

Once your mixture is ready, carefully pour it onto the primed and prepared concrete surface. Work quickly, as self-levelling concrete has a short working time—you may only have around 10 to 20 minutes to complete the pour and achieve a smooth finish. Use a gauge rake to distribute the concrete evenly and ensure it flows into all the low spots and uneven areas.

Smooth and Level the Concrete

As you pour, use your gauge rake or a trowel to smooth out the concrete and ensure an even distribution. Check for any air bubbles and ensure these are eliminated. Self-levelling concrete will begin to level itself, but you can assist this process by gently moving the mixture with your tools to fill any gaps or low spots.

Allow Adequate Drying Time

Once you have finished pouring and smoothing the self-levelling concrete, it is crucial to allow sufficient drying time. Depending on the product and environmental conditions, it may take 6 to 24 hours for the concrete to harden completely. Refer to the manufacturer's instructions for guidance on drying times, as this can vary between products. Do not step on the newly levelled surface for at least 24 hours, and wait at least two days before placing any furniture or heavy items on it.

Troubleshooting

If you encounter any issues during the process, such as uneven levelling or rapid drying, refer to the manufacturer's troubleshooting guidelines. Common issues may include incorrect mixing or application, high temperatures, or low humidity. Remember that self-levelling concrete is sensitive to temperature and humidity, so try to control the working environment as much as possible.

Frequently asked questions