How to Add Concrete to Existing Concrete

Introduction:
When it comes to home improvement projects, adding new concrete to an existing concrete surface can be a cost-effective and practical solution. This method is often used to repair or improve the look of old, worn-out surfaces or to create a more durable and visually appealing finish. In this article, we will cover the steps you need to take to add concrete to existing concrete successfully.
Step 1: Assess the Existing Surface
First, examine the condition of the existing concrete surface. It should be structurally sound, which means no large cracks, crumbling areas, or signs of significant damage. If the surface is not in good condition, it may require more extensive repairs before new concrete can be added.
Step 2: Clean the Surface
Preparing the surface is crucial for ensuring that the new and old concrete bond effectively. Begin by sweeping away any loose debris and dirt. Use a power washer or garden hose with a strong jet spray to remove any remaining dirt and residues. For stubborn stains, you can apply a concrete cleaner with a scrub brush and then rinse thoroughly.
Step 3: Apply a Concrete Bonding Agent
To create a solid bond between the old and new layers of concrete, apply a high-quality bonding agent on the clean surface. Check the instructions on the product label for recommended application techniques and drying times.
Step 4: Mix New Concrete
Following the manufacturer’s instructions, mix your new concrete in a wheelbarrow or mixer until it reaches a consistent texture. Be sure to mix enough material for your project – keep in mind that mixing too little may result in an inconsistent finish.
Step 5: Apply the New Concrete
Before applying your fresh batch of concrete, dampen your existing surface with water. This helps prevent the old concrete from drawing moisture out of your new layer too quickly. Use a shovel or trowel to apply the new concrete over the old surface, starting at one end and working your way across.
Step 6: Level and Smooth
With a straight edge or screed, level the new layer of concrete, making sure it’s even and smooth. Use a float to remove any ridges and fill any depressions left behind by the screeding process. Smooth out the surface with a steel trowel to achieve your desired finished look.
Step 7: Control Joints
Adding control joints helps prevent cracking in your new layer of concrete. The general rule of thumb is that control joints should be spaced at distances equal to 24-30 times the depth of the concrete slab. Use a jointer tool or a saw with a diamond blade to create control joints in your fresh layer of concrete before it hardens completely.
Step 8: Curing Process
For optimal strength and durability, be sure to let the new concrete cure properly. Keep the area damp for at least three days after pouring by misting with water or covering with plastic sheeting. Avoid walking on or placing heavy objects on your new surface for at least seven days to ensure proper curing.
Conclusion:
Adding concrete to an existing surface can be a cost-effective solution for repairing or enhancing an area in need of some TLC. With careful planning and execution, you can expect optimal results that will stand up to time and wear. Now that you know how to add concrete to existing concrete, you can confidently tackle your next home improvement project!