How to Level a Concrete Floor

Learning how to level a concrete floor is essential for ensuring both the visual appeal and functionality of any space. Whether you're working on a basement floor, garage, or bathroom area, a flat and even concrete floor is key for safety and the installation of flooring materials like tile, carpet, or laminate. The presence of an uneven concrete floor can create serious challenges, including tripping hazards, water pooling, and difficulties in laying new flooring. A concrete slab that is out of level often needs correction before moving on to a finished floor. Fortunately, with the right tools and techniques, even a beginner can learn how to level a concrete surface. Using a self levelling compound is a cost effective solution for restoring an existing concrete floor to a smooth and usable condition, you can then tile and lay flooring on top with no issues, let us guide you through all of the steps.

​Tools and Equipment Needed for the Job

To level a concrete floor, you will need:

• Concrete grinder
  
• Self levelling compound or floor levelling compound
  
• Primer
  
• Mixing paddle
  
• Slow speed drill
  
• Spiked roller
  
• Spirit level
  
• Concrete leveller
  
• Trowels and buckets
  
• Safety equipment
  

Having all the materials on hand before you begin makes the process much smoother.

​Preparing the Area for Levelling

To level a concrete floor, begin by preparing the space. Remove all furniture and any floor coverings such as carpet or tile. The floor must be completely clean and dust free! Sweep and vacuum to remove all dust, dirt, and debris. Pay close attention to corners, expansion joints, and other hard-to-reach areas. Inspect the surface for cracks or uneven areas. Use a concrete filler to patch cracks and holes, especially those deeper than 10mm. Identifying structural issues is important, check the integrity of the slab. Use a spirit level to assess the floor condition and level. Mark the low spots and high spots clearly so they can be targeted later in the process. A tape measure can help measure differences in elevation, especially if the slope is subtle.

​Identifying Uneven Areas

To identify uneven areas, use a long straightedge or concrete leveller. Start at the lowest point and work your way outwards. A tape measure is useful for noting how much variance there is across the surface. The goal is to eliminate all raised areas and bring low areas up to a consistent level. Uneven surfaces can often be traced to shifting soil or settling foundations. Once you’ve identified these, determine if the existing concrete floor can be corrected with a self levelling compound or if more extensive repairs are needed.

​Grinding Down High Spots

Raised areas in the slab must be addressed before any compound is applied. A concrete grinder is the best tool for this task. Use it to grind down high spots and create a smooth surface. Always wear safety equipment including goggles and a dust mask, as this process creates a significant amount of dust. Work in small sections to maintain control. Be cautious around edges and corners to avoid damaging adjacent surfaces. Grinding is a crucial step for achieving level floors and avoiding the need for excessive compound later on.

​Applying a Primer for Concrete Leveller

Before applying a self levelling compound, apply a primer to promote bonding. Use a roller or brush to spread it evenly across the slab. Follow the manufacturer’s instructions for coverage and drying time. A well-primed surface allows the levelling material to adhere properly and set to the right consistency. Let the primer dry fully before continuing. In areas with excessive moisture, perform a moisture test to ensure the surface is ready. This is especially important if the slab is located in a basement floor or other humid environment.

​Mixing and Applying Self Levelling Compound

Next, mix the compound using a mixing paddle attached to a slow speed drill. Mix until you get a smooth, pourable consistency. Mixing too quickly can introduce air bubbles or lead to separation of the components. Self levelling compound is designed to flow freely across the floor and settle into any low spots. Pour the compound at the lowest point and let it spread evenly with a trowel. Use a spiked roller to break up surface bubbles and help with distribution. Some compounds may be labeled as self leveling cement, self levelling concrete, or concrete self levelling compound, but they generally serve the same purpose. For very uneven areas, you may need to apply more than one layer. Always follow the manufacturer’s instructions for drying times before reapplying or walking on the surface.

​Allowing the Self Levelling Compound to Dry

After application, allow the levelling compound to dry without disturbance. Keep windows open or use fans to promote air circulation (but not too much!) Avoid rapid drying, as this can lead to cracking or uneven curing. Drying times vary depending on the product, room temperature, and thickness of application. Once the surface is dry, check again with a spirit level. Use your concrete leveller to double-check for any dips or raised areas. If necessary, apply another thin coat of compound.

​Achieving a Level Concrete Floor

To achieve a truly level concrete floor, check for both vertical and horizontal evenness. Apply additional coats of self levelling compound where needed. Revisit areas that may still contain uneven spots and adjust accordingly. Use a concrete grinder again if the finished product contains minor bumps. A smooth surface is vital if you plan to install delicate flooring like vinyl or hardwood.

Using a Concrete Leveller Tool

A concrete leveller tool, often shaped like a long straightedge, is helpful for verifying level throughout the project. Run it across different sections of the floor to identify high and low spots. These tools are especially useful when spreading compound in large rooms. Check for uneven concrete or unexpected dips along edges and in corners. Continue applying compound and grinding as needed until the entire surface is uniform.

​Floor Level Considerations

Before installing new flooring, evaluate the floor level in context with adjacent rooms. An uneven transition between a concrete floor and finished floor materials like tile or laminate can be problematic. Use a spirit level and concrete leveller to ensure the floor is balanced across thresholds and entrances. Keep in mind that changes in floor level may impact door clearances and baseboards. Addressing these issues before installation saves time later. You may also want to use a moisture metre for extra piece of mind before laying tiles or real wood flooring, each flooring manufacturer will have guidelines you can test for.

​Safety Precautions for Concrete Work

Working with self levelling concrete involves tools and materials that can be hazardous. Always wear protective gear, including gloves, goggles, and a dust mask. Ventilate the room properly and clean up any spills or dust immediately. Use care when operating power tools like grinders or drills. Follow all safety instructions included with each product and tool.

​Conclusion and Final Check

Once the concrete levelling compound has fully dried, do a final inspection. Use a spirit level to verify that the entire surface is even. Look for any remaining dips or raised areas, and correct them as needed. Apply a concrete seal if you plan to leave the floor exposed. If you’re laying new flooring, confirm that the concrete slab is completely dry, smooth, and level before proceeding. Knowing how to level a concrete floor will improve the safety, look, and longevity of your space. If the project feels too large or if the concrete is severely damaged, consider consulting a professional. But for most uneven floors, self levelling concrete and a little patience can deliver excellent results, good luck!