Refinishing existing concrete is a really cost effective way of breathing new life into old driveways, garage floors, patios and so on. These days there are also a number of finishes to choose from to make that concrete look brand new again, or even become a show piece.
Depending on what type of finish you are going after, there are right ways and wrong ways to prepare an existing concrete surface for refinishing. This guide will be covering essential tips for correct concrete surface preparation. Failing to prepare properly can result in a sub-par finish, where any concrete artistry will end up being a complete waste of time, energy and money.
Jump To:
Mechanical Abrasion
Shotblasting Techniques
Scarifying A Concrete Surface
Dustless Concrete Grinding
Concrete Scabblers
The Ride On Floor Scraper
Electric Concrete Shaving Machines
Mistakes To Avoid With Concrete Surface Preparation
Mechanical Abrasion
Using purpose built tools designed for the task, mechanical abrasion and scraping is one of the most effective methods of preparing old concrete for refinishing. Existing sealers, old coatings, adhesives and other contaminates are quite easily removed.
Another advantage of this prep method is mechanical abrasion lightly scuffs up the surface, leaving it slightly rough for easy adhesion of the new surface. Smooth concrete is not conducive for new glues and sealants to adequately adhere to, and it’s much better if the concrete has been lightly pulverised first.
Shotblasting Techniques
This method involves thousands of steel shot pellets being propelled at the concrete surface. It’s a dust-free way of preparing the concrete, while at the same time being highly effective at removing old paint, dirt, grime and other contaminants.
The pellets leave the surface scuffed for easy adhesion of new glues and coatings, ensuring an even finish free of unwanted debris. The 200mm shotblaster tool is one of the most popular models for concrete and steel shotblasting, or even the self-propelled 380mm model for larger surface areas.
Scarifying A Concrete Surface
This is a specialist piece of machinery that does as the name suggests – scars the surface of the concrete. It achieves this by using tungsten or hardened steel flails that basically batter the surface and leave it clean and rough, ready for concrete refinishing.
The attachments for scarifying can be attached to concrete grinding machines. Some attachments will even leave the concrete with the appearance of a freshly laid slab, if that’s the result you want to achieve.
Scarifyers are also often referred to as concrete planers, rotary cutters and milling machines. They can be finely adjusted for precision cutting depth of the surface of the old concrete.
Dustless Concrete Grinding
For the sake of your health as well as leaving as little mess behind as possible, dustless grinding is a really good choice for effective concrete preparation. Whether you want a coarse finish or one that’s really fine and relatively smooth, there are attachments for today’s concrete grinding machines to suit all requirements.
Using diamond segmented abrasives in a variety of grit levels, rotating disks will both level and smooth off the surface of ageing concrete, and all dust is collected in a dust bag, rather than filling the air with fine grit and coating everything in the surrounding area.
There are also hand held models of concrete grinder for those smaller tasks, or for simply levelling off uneven joints.
Concrete Scabblers
If the concrete you need to refinish is badly pitted and scarred, then using a concrete scabbling machine might be the go. Scabblers dig deeper into the surface than grinders or scarifying machines do, and use a hammering piston powered by compressed air to get the job done.
Scabblers can remove anywhere up to 6mm from the surface of the concrete at a time, and are really the tool of choice for those particularly rough jobs and very old concrete.
The Ride On Floor Scraper
These are perfect for preparing very large concrete surfaces and, just like the ride on mower, you don’t need to push this piece of machinery around.
This bit of kit is fitted with a scraping tool at the front and has been designed to expediently remove old vinyl, carpet, linoleum, parquetry and the like. It can even be used to lift up ceramic tiles and rubberised sporting surfaces, such as on a running track.
The end result will be a surface stripped down to bare concrete that can then be properly prepared with grinding, shotblasting and so on.
Electric Concrete Shaving Machines
A concrete shaver is really a multi purpose tool than can plane the concrete, scar the surface, level uneven joints, remove epoxy and other substances, leaving the surface clean, contaminant free and ready for the new coating.
One really major advantage of concrete shaving is if you want to leave the concrete surface as is without a new coating. Your “new” surface will now be slip-free, providing a safe surface to walk on even in wet weather; so perfect for refinishing driveways and footpaths around the home or place of business.
Mistakes To Avoid With Concrete Surface Preparation
Before you go ahead and apply the new surface, whatever it is you choose, there are a few key things to be mindful of first.
Whether you are doing the job yourself, or hiring a contractor, be certain to check the concrete thoroughly for any signs of moisture. If you are planning on applying some sort of epoxy coating, then moisture in the concrete will cause bubbling in the new surface, and you don’t want that. Worst case scenario is the new surface might even start to flake and peel off.
Also, use a dust collector once the surface has been prepared, as any dust left behind could cause the new surface not to adhere to the concrete.
Make certain all concrete joints are also smooth and level before going ahead and applying the new surface to ensure the desired result.
With the right tools for the job at hand and a bit of industry know how, the options for rejuvenating concrete surfaces these days are many, and the results can often be stunning. Usually you won’t need to lay new concrete to breathe new life into it. Just prepare it correctly, successfully apply the new surface of your choice and it’ll last for many years to come.
View the entire range of Surface Preparation Equipment available for lease at Dynamic Hire >
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