Concrete is a porous material and as it cures, the top surface becomes less dense than the core. Densification results from applying a silicate hardener to the concrete. This application creates a chemical reaction whereby the densifier combines with lime. This also creates additional cementitious material on the surface of the foundation and filling in and hardening the pores and imperfections. Densifiers used on non-polished floors can reduce maintenance costs and improve surface hardness. On polished concrete, they help deliver an excellent polish that can withstand liquid spills and not require the final application of a sealer.
If you choose to apply a stain to your floors, we suggest two options. With acid stains, you need to apply the densifier after applying the acid stain and rinsing and neutralizing the surface. Because the densifier creates an impermeable bond, covering your surface with it first might inhibit penetration of the acid stain. If your choice is a dye, you may proceed with applying the densifier followed by the dye. Because they are 100% soluble, dyes penetrate the surface easily and do not rely on a chemical reaction to bond as do acid stains.
As hard as contractors work to prepare and finish concrete foundations, there is always the potential for cracks or more serious issues down the road. When we evaluate the integrity of a concrete substrate, our first task is to try and determine what caused the damage. Is it superficial or is it a more serious structural problem? Is the damage confined to a specific area or is it widespread? And if there are cracks, are they continuing to spread or have they stopped moving? Is there surface delamination and, if so, how serious is it? Some of the most common problems we face include:
- Corrosion of the reinforcing steel
- Freeze/thaw disintegration
- Alkali aggregate reaction
- Drying shrinkage
- Plastic shrinkage
- Severe cracks from structural loads
We use several materials and methods to resolve problems with concrete substrates. For general cracks, we use polyurea. Once everything has been repaired, we will apply a cementitious coating over the entire surface followed by a waterproof sealer.
With the technological breakthroughs in repairing commercial and industrial flooring today, it is often possible to resurface a damaged concrete substrate. There are many options available to us for making your floors look like new. Resurfacing concrete floors is a sound solution for:
- Repairing cracks
- Updating discolored or outdated finishes
- Removing surface imperfections
- Leveling older floors
Our first job is to determine the soundness of your existing substrate. If it is damaged from severe weather conditions, has heavy cracks, or the steel support system has rust decay, resurfacing might not be an option. After that, if our engineers determine we can proceed with preparing the surface, we will fill cracks and blemishes and methodically remove greases, stains, oils, coatings, sealers, and paints. Once the surface is clean, we will roughen the entire floor with a shot blaster. This process will create a sandpaper-like finish, allowing for the old concrete to bond with the new surface. Finally, we will apply a cementitious-based material on top of the old substrate, leaving you with a beautiful new floor to polish and seal. Otherwise, you may choose from a wide array of products that will protect your floors for years to come.
The discipline of concrete testing allows the project manager to assess fresh concrete and make certain it will reach the hardness required for the job. Over the years, we have seen technological breakthroughs that speed up the curing process, such as heating blankets, additives, and vapor retarders. However, the general opinion of contractors is to wait three days before strength testing.
To ensure accurate test results, our process includes collecting several core samples from each job and having an independent lab perform the analyses. There are a number of tools available for testing, including:
- Concrete Sampling: We take several samples throughout the pour to confirm we mixed the concrete to predetermined specifications.
- Temperature Measurements: This is ideally done in the transporting vehicle to get the most accurate results; however, it can also be done at the job site as long as strict protocols are followed for completely inserting the thermometer.
- Pull Out: A metal rod is inserted into the concrete when it is poured. After the slab has cured, the rod is removed and the conical shape, as well as the force required to remove it, can measure the compressive strength.
Grind & Seal Floors
Polished concrete floors and grind and seal floors are popular options for industrial and commercial flooring. These are great choices and when finished, look very much alike. Concrete polishing is a more labor-intensive process. It requires a polishing machine fitted with diamond grit discs that start with coarse grit and finish with fine grit. This process will allow you to achieve your desired finish, from matte to high gloss.
The process behind grind and seal floors is as described: grinding the floors and finishing the process with a sealer. First, grind the floors to remove glues and contaminants. Once the floor is clean, patch divots and cracks. Next, you can do a second grinding to provide a smoother finish. After this grinding, clean every part of your floor of all dust and debris. Once cleaned, you may choose to apply a custom stain or dye. Whether you leave the natural concrete exposed or apply stain, the final application includes a topical sealer. Grind and seal floors require less grinding, honing, and polishing because the topical sealer will provide shine. This floor system is an economical solution, as this process can be completed in less time.
Maintaining commercial and industrial floors varies based on how the surface is finished. For epoxy and polyaspartic finishes, we recommend daily sweeping in open trafficked areas. This will remove grit and dirt, which may cause abrasions and early wear on the flooring. Every few weeks, use a high-quality sponge to mop the floors thoroughly and rinse with clean, hot water. Make sure to replace the water frequently. As an alternative, you may consider adding ½ cup ammonia to each gallon of water.
You can maintain terrazzo in several ways. You may sweep the floor to remove dirt and debris. Using plain water, scrub the floor and try to keep it moist for several minutes. Rinse the floor using a clean mop, warm water, and a wet vacuum or squeegee to remove all dirty water. For an easier maintenance program, Bona Stone Cleaner can be found in many stores and is a highly rated “green” product. Simply spray the floor with this cleaner, then run a flat mop over the surface every week or so. Never use an oil-based cleaner or stain remover on terrazzo flooring, as these products can cause permanent discoloration.
Polyurea Joint Repair
Many industrial and commercial facilities are built with a concrete foundation that can be polished and finished in a number of ways. Concrete foundations require expansion joints to be cut into the surface. This is an important finishing process because these cuts are a pathway for potential cracks. After cutting the surface, fill the expansion joints to keep them free of dirt and unwanted debris. Our project managers suggest and use polyurea-based joint fillers specifically designed for indoor use on commercial and industrial concrete floors. We provide a polyurea solution for concrete floors needing crack or joint repair, and a more durable polyurea option for floors that see heavy traffic, heavy loads, wheeled carts, and forklifts. The two types of polyurea joint filler we offer are:
- Semi-rigid filler: used to repair joint cracks in newly-poured slabs or to repair cuts in older floors.
- Structural fillers: primarily used to restore damaged concrete surfaces. For surfaces that have holes, broken edges, or severe cracks, this is a great solution.
Commercial and industrial concrete flooring must be able to withstand heavy traffic, thermal cycling, and shrinkage. From distribution centers and grocery stores to big box home centers, polyurea is a great choice for filling, sealing, and repairing concrete floors.
We highly recommend a final sealer coat to add a non-slip surface, prevent color changes, and prevent the peeling of an epoxy flooring system. Be sure your floor has dried and cured thoroughly. If the area faces sunlight, we also recommend adding UV to the coating in order to protect harmful rays from discoloring the floor. The process for sealing concrete includes:
- Making sure the surface is clean. At this point, you can add stains, dyes, polish the surface or leave it bare.
- Installing any decorative topping that meets your needs.
- Applying the sealer.
Concrete floors are naturally porous, and adding a topcoat sealer will help preserve them from the wear and tear of foot traffic, equipment shifts, and general operations. Sealing them will also enhance the color if you added a stain or dye and provide a reflective source from the overhead lighting, reducing energy costs.
Stained concrete is a great choice over linoleum, tile, or stone for commercial flooring applications. You have many color choices, and you may resurface concrete with specialty finishes: either polished or ground and sealed.
Staining concrete provides permanent color. The color penetrates the porous surface, creating a durable finish that will never flake or peel like paints or coatings. Staining will allow your creative skills to flourish, and you can choose from single colors or multiple colors. You may ask for a faux marble finish, wood plank finish, or custom graphics. Once you have made the decision to choose to stain your concrete floor, you have two choices of base material:
- Acid-based stains interact chemically and then create unique color effects that can replicate granite, marble, quartzite, or wood. The color choices with this solution generally fall in the tan to brown range.
- Water-based stains are available in more colors and allow you to custom blend your own colors. You may also use unique application tools to install an interesting flooring system.
Substrate Slab Correction
Concrete slabs have come a long way in terms of preparing the site properly before pouring concrete. If you don’t install a vapor barrier, this may present problems in the future. If you don’t test the cement to make certain it is mixed as directed, problems may arise. When we see cracks or chips, we must consider how the facility is used, when the substrate was constructed, and then take appropriate steps to be certain that it is sound.
When cracks or chips appear, the general solution has been to inject the damaged area with an epoxy filler. This may solve the problem for a while, but what if the cracks are the first sign of a failing substrate? In commercial properties, cracks may be the result of poor rebar use when preparing the foundation, ground settlement during the curing process, or hydro-static pressure. As a result, not properly addressing the problems can also lead to moisture rising from the ground and allowing mold to build up, causing further damage. If your foundation is not level and there are no indications of issues underground, applying a cementitious floor leveling layer can resolve the problem. If, however, there are indications of ground settlement, injecting polyurethane foam concrete may be the appropriate solution.
There is an age-old saying that proper preparation prevents poor performance. Preparing concrete surfaces for coatings, overlays, dyes, and stains is necessary in order to achieve the best possible outcome. As a general rule, there are four stages in preparing a concrete surface for an overlay system:
- A thorough inspection of the substrate
- Removal and repair/replacement of damaged areas, including cracks and divots
- Decontamination of the concrete surface
- Establishing a surface profile
The last two stages are critically important in order to prevent a system failure. Many substrates have suffered from chemical spills, grease, oil, and contamination. You must clean these aggressively until the natural porosity returns to the concrete. When the surface is sufficiently clean, you also need to establish a surface profile. For proper bonding of overlays and coatings, there are guidelines regarding how aggressive the preparation should be. The thicker the overlay is, the more aggressive the surface profile should be.