Concrete Sanding

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Feb/02/22

An Overview On Concrete Sanding 

More and more, concrete is becoming a core material used in various building projects from residential to commercial. Concrete has been revered for its durability and continuously increasing strength. Its composition allows it to experience consistent weathering stress with little to no major repercussions. But, concrete couldn’t function at its highest ability without the proper sealing and sanding process. Sanding concrete is the key to sealing the material such that it can be coated with a particular finish and used in day-to-day life.  

 

Why Sand Concrete?

When looking to finish your concrete flooring and walls, the sanding process is one to not skip. There are 4 main reasons why sanding concrete is an indispensable step. Sanding concrete works to improve the surface texture and appearance, smooth rough and jagged edges, remove stains or paint streaks, and repair any imperfections.

 

 

  • Surface texture and appearance. When using concrete for flooring, specifically residential flooring, there is a high chance it was chosen not only for its strength and durability, but also its aesthetic appearance. Most homeowners opt to coat the final concrete slabs with finishes that match a particular style or look. Sanding concrete is a necessary step to achieve the desired finished product.
  • Smooth rough and jagged edges. Rough and jagged edges are a common and unfortunately unavoidable result when pouring concrete. Protruding concrete pieces can be sharp and cause preventable injuries. The sanding process buffs these jagged edges and corners resulting in a smooth and less injury-prone surface. Aside from flooring and driveways, concrete tables and countertops should also be inspected for sharp pieces in need of sanding.
  • Remove stains and paint streaks. In construction projects, inevitably some droplets of paint or other staining agents will make their way onto the newly poured concrete. If removing the paint and stains with cleaners or specially-formulated solutions proves to be unsuccessful, sanding the concrete will remove the layer that has been tainted and restore the original look of the concrete.
  • Repair imperfections. During the concrete pouring, drying, and curing processes, there is a chance the slab will begin to crack. To fix these gaps, a concrete crack filler can be applied to remedy the issue. Though this causes texture imperfections, sanding after the filling agents have dried results in a crack-less and even final product. 

 

Preparing The Floor

The first step in sanding concrete is prepping the slab. Much of the concrete’s aesthetic and strength comes through proper preparation techniques. Begin by inspecting the floor or slab for any glaring imperfections and fix them accordingly. From there, remove any major bumps. These generally develop around corner areas as a byproduct of the pouring, drying, and curing process. Bumps are best removed sooner than later as the more time they spend on the slab, the harder it is to remove them. 

 

Professional Sanding Vs. DIY Methods

Once the prep work is completed, the sanding can begin. It can be tempting to take on the sanding process in a do-it-yourself manner as the necessary tools are relatively widely available. In fact, it’s one of the most common frequently asked questions. However, for a perfectly smooth result, a professional’s hand is the better choice. It can be difficult to properly remove all the imperfections and smooth the slab down to a single uniform piece. While it may be more expensive to hire a professional, the alternative of fixing a poorly executed DIY job will rack up a similar price tag. 

 

Types Of Sanders

There are various concrete sanding options available on the market. For starters, the main difference in sanders is whether they are used for wet concrete sanding or dry concrete sanding. Dry sanders are equipped with an insert for a vacuum to suck up dust and reduce particulates. Wet sanders are “water-fed” meaning there is a hose connection that provides a steady flow of water. There aren’t any major advantages of using one time of sander over the other. Wet sanders are said to produce a smoother finish and are less abrasive than dry sanders. Dry sanders, on the other hand, are more aggressive and best used to remove more, rougher material in less time. 

 

 

Polishing Concrete 

For concrete countertops, floors, and walls, polishing is a step that should never be skipped. Polishing concrete helps improve the overall appearance of the slab and removes any imperfections that may have emerged in the pouring and curing process. For a proper polishing job be sure to have the following tools on hand:

 

 

  • Polisher. The polisher is the primary tool you’ll use in the polishing process. We recommend a variable speed polisher so you can adjust the speed settings accordingly. These are generally handheld and relatively easy to use. You can also try an angle grinder tool depending on your specific needs. If you are unsure what to use, it’s best to consult a professional to avoid producing a result you don’t like.
  • Grinding pads. For areas with stubborn aggregate, grinding pads break down blemishes and areas of inconsistency to produce an even-looking surface. Grinding pads range in coarseness from fine-grit sandpaper to coarse grit sandpaper. Depending on what you may need, you may use either or both in your polishing process.
  • A squeegee. A squeegee or other plastic wiper is needed for preparing the concrete for polishing. It is important to clean the concrete before polishing so that any dust, debris, or other unwanted particles are removed. To clean the concrete, use water and the squeegee to wipe down the surface.
  • PPE. Personal protection equipment is important in any construction project. For polishing, it is best to have goggles to shield your eyes from dust and flying grit, earplugs to protect your ears from the loud machine, and a mask to avoid inhaling sand and concrete particles.
  • Sanding Pads. Depending on your project, there may be areas you want to keep free of polish. Sanding pads, also called hand polishing pads or diamond polishing pads, provide a protective area over regions of the concrete that you may want to keep free of polish. 

 

Types of Concrete Finishes

How you choose to finish your polished concrete slabs depends heavily on your style. There are three main regular concrete finishes to choose from, the smooth finish, the salt and pepper finish, and the exposed aggregate finish, each of these should be then finished off with a chemical concrete hardener or a concrete sealer. 

 

  • Smooth finish. The smooth finish is the easiest and simplest finish to achieve. While it can be done by hand, it is recommended to use a random orbital sander. For this specific finish, there are no concrete layers that are being removed. Rather, the polisher smoothes and shines the top layer of concrete until the desired look is achieved.
  • Salt and pepper finish. Aptly named salt and pepper, this finish is white and black speckles that resemble the texture of these common spices. This is characterized as an intermediate finish, in which a thin layer of concrete is sanded off allowing the aggregate to be exposed.
  • Exposed aggregate finish. This is the most complete of the three finishes. In an exposed aggregate finish, a lot of material is removed. This type of finish should neither be done by hand nor done without the advice of a professional. It is difficult to achieve without a powered polisher or sander and even harder without experience.

 

 

Final Touches

The sign of a quality concrete and sanding finish is a uniform look that stretches across the entire slab. Arguably the most difficult part of this sanding and polishing process is achieving uniformity. It requires even sanding throughout the entire slab. If you’re planning on staining your concrete to develop a darker color, you still need to sand your entire floor, not just the areas with imperfections. Because sanding opens up pores in the concrete if you sand one section and not the other, the stain will penetrate the slab unevenly and the coloring that develops will look different all across the surface.

 

For Large Projects, Call A-Core

A-Core has been helping individuals and companies alike in delivering high-quality, professional concrete services. Our client-centric approach paired with a talented team of experienced managers, project foremen, estimators, mechanics, and administrative staff, means good work done right. Our dedication to safety and service is an experience that makes for a lasting impression on our clients and partners. For any concrete sanding needs or other concrete services, call A-Core today.