Concrete floors have come a long way from their industrial roots. Once confined to factories and warehouses, polished and stained concrete floors are now making waves in modern homes. Their sleek, minimalist look complements various interior designs, making them popular for homeowners looking to update their flooring. Whether replacing old flooring or starting from scratch, finishing concrete floors is a rewarding DIY project that adds value and style to your home.
Proper planning and implementation allow you to transform your concrete surfaces into stunning, durable, practical, and stylish floors. Here, we will walk you through the process, from preparation to the final polish, to make the project simple and successful.
Preparing the Concrete Floor
Before diving into the finishing process, you need to prepare. This initial stage sets the foundation for a successful project.
Cleaning the Surface
Thoroughly clean the floor before anything else. This removes dirt, debris, and existing coatings that could interfere with the new finish. Sweep the entire surface to remove loose debris and dirt. Then, scrub the floor with a stiff-bristled brush and warm, soapy water. To remove stubborn stains, use a solution containing trisodium phosphate or a similar cleaner. Follow safety guidelines and ventilate the room properly throughout this process. Rinse the floor to remove dirt and residue and allow it to dry before moving on.
Assessing and Repairing Damage
Once clean, evaluate the floor for any damage that needs addressing. Inspect the entire surface for cracks, holes, or uneven areas. Mark any areas that require repair for easy identification and remove loose concrete or debris from the damaged areas. For small or superficial cracks, use a concrete filler and a caulk gun to fill in the gaps. For large holes or cracks, use a vinyl concrete patch and follow the instructions on the packaging for your product. Allow all repairs to cure fully before moving to the next step in the process.
Leveling and Grinding the Concrete
Leveling and grinding the concrete surface creates a smooth, even base for the final finish.
Testing Concrete Hardness
Before grinding, determine the hardness of your concrete floor. The results will inform your choice of grinding equipment and techniques. To figure out your floor’s Mohs hardness level:
- Obtain a set of Mohs hardness picks.
- Start with a midrange pick (around #6) and gently draw a line on an inconspicuous floor area.
- If a visible scratch remains, try a lower number. If there is no scratch, try a higher number.
- Continue until you find the pick that barely scratches the surface. This number represents your floor’s Mohs hardness level.
Grinding Process
With the hardness determined, begin grinding. This process removes surface imperfections and prepares the floor for polishing:
- Rent a concrete grinder with a complete set of diamond-bonded discs ranging from 40-grit to 3000-grit.
- Start with a coarse grit (40 or 80) to remove major imperfections and stubborn stains.
- Progressively work through finer grits (150, 300, 400) to smooth the surface.
- Apply a concrete densifier after using the 400-grit disc. The densifier hardens the concrete and reduces porosity.
- Continue with finer grits up to 3000 for a high-gloss finish, if desired.
Be diligent and thoroughly clean the floor using a wet-dry vacuum to remove dust and debris between each grinding step.
Staining and Polishing the Concrete Floor
The final stage of finishing concrete floors involves staining (optional) and polishing to achieve the desired look and protect the floor.
Choosing the Right Stain
Two types of concrete stains are readily available in most home improvement stores: acid- and water-based. Acid stains are powerful enough to penetrate the concrete, creating a natural, variegated look. Water-based stains penetrate less deeply but offer a broader color palette and a more uniform finish. Prosoco’s GemTone Stain, for example, comes in 25 different tones—ranging from rose quartz to emerald. The stain penetrates deep into the concrete, so it will not easily flake and peel. Consider the style you are aiming for and the current state of your floor when choosing a stain type.
Applying Concrete Stain
Once you have chosen your stain, the application process begins:
- Conduct a test patch in a small, hidden area to check the color and finish.
- Apply the stain evenly using a sprayer, brush, or roller, following the manufacturer’s instructions. Use long, overlapping strokes to avoid streaks and get even coverage.
- After you cover the surface, allow the stain to dry completely. Note that drying times vary based on humidity and temperature.
Multiple Layers and Designs
For a more intricate design or deeper color, apply multiple layers of stain. For best results, each layer must dry completely before applying the next. You can also use painter’s tape and stencils to create patterns or borders for a custom look.
Sealing and Polishing
Sealing protects the concrete and enhances its appearance while polishing concrete floors enhances their natural shine. Apply a high-quality concrete sealer, like LS premium concrete sealer, with a roller or sprayer to protect against stains and moisture. After it dries according to the manufacturer’s recommendations, use a high-speed burnisher with progressively finer polishing pads. This step will create a high-gloss finish. Make multiple passes with each pad, working in a consistent pattern across the floor, and clean between each pass to remove any dust or debris.
Maintaining Finished Concrete Floors
Properly maintaining your finished concrete floors will keep their beauty and integrity intact.
Regular Cleaning
Sweep the floor each day to remove loose dirt and debris. Use a damp mop once a week with warm water and a pH-neutral cleaner made for concrete floors. When spills occur, address them promptly to prevent staining.
Protective Measures
Protective measures help maintain the floor’s finish and appearance. We recommend placing mats at entry points to minimize the amount of dirt and moisture that reach the floor. Placing furniture pads underneath your furniture will help avoid scratches and abrasions on the floor’s surface. Avoid dragging heavy items across the floor to prevent gouges and scratches.
Periodic Resealing
Over time, your finished concrete floor may require resealing. We recommend doing this every 2–3 years or as needed based on the amount of wear and tear. To do so, clean the floor thoroughly before applying the new coat of sealer. Follow the manufacturer’s instructions for reapplication for best results.
Handling Stains and Damage
For minor stains, use a damp mop with a neutral cleaner. For major stains, use a poultice made from a cleaner and an absorbent material like cat litter. Mix into a paste, apply to the stain, cover, and let it sit. Remove the poultice once dried.
Cost Considerations
The cost of finishing concrete floors varies widely depending on several factors:
- DIY vs. professional installation
- Size of the area
- Desired finish (basic polish vs. elaborate staining)
- Quality of materials used
According to Angi, expect to spend between $2–$16 per square foot for a basic polished concrete floor, with about two-thirds of that price accounting for labor costs. In some cases, this figure is higher, depending on the complexity of the design.
Environmental and Stylistic Benefits
Concrete floors are sustainable, durable, and environmentally friendly. They reduce the need for additional materials and are easy to maintain, cutting down on cleaning products. Their mass also aids energy efficiency, keeping spaces cooler in summer and warmer in winter.
