Concrete, by its very nature, is a hard substance and hard to work with, unless you have the proper tools and knowledge. We at PennCoat frequently deal with new and existing concrete surfaces, and sometimes preparing the surface can be laborious. However, surface preparation is essential for a proper finished look and for putting down coatings, stains or overlays. Here are four methods commonly employed to prepare or resurface concrete.
A grinding machine can be equipped with a diamond-impregnated disc to smooth a concrete floor. The discs rotate horizontally to remove paints and coatings, texture the concrete or grind and polish it to a perfectly uniform surface. Diamond-segmented abrasives are used to remove urethanes, epoxies and other coatings, as well as to remove imperfections and polish the surface. The diamonds are embedded in a resin or metal matrix and bonded to a backing plate. The rotary action of the diamond disc removes the desired amount of material, and a skilled hand is needed to avoid uneven or gouged surfaces. Normally, you would remove no more than 1/8 inch of material through grinding. The walk-behind grinders can have one to four discs simultaneously rotating at speeds up to 3,000 rpm. Multiple-disc machines use counter rotating and floating heads to balance the torque and follow the floor’s contours. The diamond discs kick up a lot of dust, so a vacuum system is usually incorporated in professional units. You can also use smaller, handheld units for tight spaces and concrete countertops.
Shotblasting allows you to strip, clean and profile concrete surfaces in a single step. It’s often used to prepare concrete for overlays or coatings. The technique creates a rough texture that enhances the adhesive properties of decorative toppings. The surface remains dry and is immediately ready for further work. Shotblasting machines propel steel shot with a paddle wheel rotating at high velocities to strip the surface of its top layer of concrete, along with any coatings or paints. Naturally, the shot is enclosed within a blast chamber to prevent it from escaping — a dangerous proposition. A dust/debris vacuum collector removes the loosened material. Professionals know how to balance the choice of shot size and machine travel rate to get optimal results. The walk-behind and riding units can blasts paths up to 32 inches per pass and handle anywhere between 200 and 3,000 square feet per hour. You can get units that run on electricity, gasoline or diesel. You can’t shotblast surfaces that have elastomeric or rubbery coatings, because the steel balls bounce off the surface.
Like a grinder on steroids, scarifiers are surface milling machines to aggressively remove concrete via high-speed, multi-tipped cutting flails that chip away the surface. The cutting wheels are shaft-mounted to a removable drum, and the density of the shafts determines the working speed of the machine. A wide variety of cutter assemblies allows you to form many different profiles. You can use handheld or self-propelled walk-behind units that cut swaths up to 16 inches wide and 1/4 inch deep. Professional units may have self-leveling heads to match the surface contours of the floor.
Scabbling machines usually run on compressed air power to pound several steel- or carbide-tipped heads that nibble away at the concrete surface. The motion is similar to rapidly hammering the surface and can add a texture or decorative pattern to the concrete. It is also a useful way to prepare the surface for grouting or coating. Scabbling removes a thin layer of concrete and usually requires multiple passes to achieve the desired results. Large, truck-like scrabbling machines are often used to remove road markings from concrete highways.
PennCoat, Inc. has been providing industrial painting, commercial painting, epoxy flooring, and polished concrete services for nearly 30 years. Our experienced installers are trained and equipped with the proper knowledge and tools to ensure that every installation is installed efficiently and safely. PennCoat, Inc. provides service to Pennsylvania, New Jersey, Maryland, and Delaware. And we cover York, Lancaster, Philadelphia, Chester, Montgomery, Baltimore, Harrisburg, Dauphin, Bucks, Berks, and other counties in the surrounding area.