If you’ve been to any trendy Australian cafes lately you may have noticed a common trend that everyone is going crazy for. Polished concrete floors modernise any room and are a durable flooring alternative that looks better than floorboards or tiles.
Polished concrete is a long process requiring expertise and patience. But it is well worth the effort.
The statement appeal of a polished concrete floor is achieved with a powerful piece of equipment known as a concrete grinder. This is a versatile piece of equipment that uses diamond blades to grind the top surface of the concrete slab.
These popular grinding machines aren’t only used to achieve a stylish look in any home, they are also used when profiling floors before applying paint, levelling off a concrete slab, breaking up deposits of industrial contaminants, removing paint, or preparing for new floor coverings.
Whether you are planning on doing the concrete grinding yourself, or want to hire a concrete grinding professional, here is a quick guide to familiar yourself with how concrete grinding works.
A step by step guide to concrete grinding
STEP 1: Preparation
Concrete grinders are potentially dangerous power tools if not used correctly. Before you begin the grinding process we recommend you read through the user manual thoroughly, or check whether the manufacturer of your concrete grinder offers a free how-to course on “How to use a concrete grinder” or “How to cut concrete with an angle grinder.”
To save time and money and avoid making mistakes, we recommend going through the following questions before you begin the grinding process:
• How big is the Floor space?
• Will edging need to be included?
• Are there corners?
• Will the floor need patching?
• Will the expansion joints be filled or left open?
• How hard is the concrete?
By answering these questions you will be able to know which concrete grinder is best suited for your job, how long the grinding process will take, and which diamond blades/diamond discs are best for your job.
STEP 2: Check you are using the correct diamond discs
Concrete grinders come with many important attachments such as diamond cup wheels, diamond discs, and a vacuum hose for dust control. Without the correct diamond disc, you won’t be able to achieve successful removal jobs with your grinding machine.
Choosing the right diamond disc for your concrete grinding removal job will depend on whether you are using a wet or dry grinding process, and how hard or soft your concrete slab is.
For example: A soft bond diamond disc is better for hard concrete, whereas a hard bond diamond disc is better for softer concrete.
STEP 3: Changing the diamond discs, plugs and pads
If you have experience in woodwork or metalwork you will already be very familiar with abrasive plugs, soft discs and resin pads. Each stage of grinding a concrete floor requires switching between the different attachments that come with your concrete grinder:
Diamond Plugs: Heavy grinding work
Diamond discs: Finer grinding work
Diamond pads: Used for polishing
STEP 4: How to use a concrete grinder
There will generally be 3 different handle positions on any concrete grinder you end up purchasing. These include an operating position, tooling position (easier to tilt the machine up for switching discs and pads) and lifting and storing position (makes it easy to lift on and off trucks).
• Adjust the height of your concrete grinder to your height so it’s comfortable to use.
• If you are using a vacuum hose, make sure it is in the right position
• Always tilt the machine back slightly before you turn it on.
• Press the green start button
• All concrete grinders will come with an overload button that pops out if the machine trips out. If this happens just let your concrete grinder cool down, a few minutes will be enough, then pop the button back in and continue grinding.
STEP 4: Dust control
Grinding away the top surface of the concrete with diamond blades creates a lot of dust. A vacuum hose is an important part of the concrete grinder and will help you keep your site dust free. Alternatively, when choosing between a wet or dry grinding process we recommend wet for optimal dust control.
When using a concrete grinder safety is extremely important.
Personal protective equipment includes:
• Safety spectacles, eye shields, safety goggles or face shields.
• Steel midsoles to protect sharp nails or concrete remnants from piercing through your boots and into your foot
• Heavy duty leather or rubber gloves
• Hard hats to protect you from heavy objects falling from above
• Earplugs or earmuffs to protect your eardrums from potential damage from the loud noise of your concrete grinder.
Concrete grinding tools
Something you may not know about concrete grinding equipment is that you can also use an angle grinder to grind concrete. When you are looking to buy a grinding machine here are two concrete grinding options:
Walk-behind concrete grinders: Suited for profiling large concrete slab surfaces.
Handheld concrete grinders: Angle grinders with a diamond cup wheel or diamond disc work well in tight areas where a larger concrete grinder can’t maneuver such as corners or areas near walls. Angle grinders are also perfect for grinding down high spots on concrete floors.
Hire vs Buy
Ultimately this will come down to whether you have a lot of consistent work requiring the need for a concrete grinder, or whether this is a one time project.
Purchasing a concrete grinder will be a great investment in the long term if it will help you increase your workload.
Dos and Don’ts
• Do install new diamond discs every time
• Do complete a full check of your concrete grinder before you begin. Make sure all cables and vacuum hose are not damaged and extractor vents are clear.
• Do always wear gloves when switching between diamond plugs, diamond discs and pads.
• Don’t use a concrete grinder without the correct personal protective equipment
• Don’t forget regular maintenance on your grinding machine
• Don’t use the wrong diamond cup wheel
For efficient, professional and great quality concrete grinding removal jobs avoid these common mistakes:
• Not correctly inspecting the concrete slab before you begin
• Selecting cheap diamond discs that break easily
• Rushing through the grinding process
• Be patient and use a focused, steady rhythm when using your grinding machine. Rushing will result in having to go back over the surface of the concrete multiple times to get the glue off completely.
• Save time by planning the pattern you are going to follow before you begin. This will prevent any cables, such as the vacuum hose and electrical cord, from tangling and getting in your path too much.
• If edging is required you will be using two different concrete grinders. Take extra care with blending the two grinding paths together, otherwise the difference will stand out when you apply a finish.
Concrete grinding is a challenging process that can be a waste of time, money and effort when not done correctly. If you want an efficient and professional concrete removal job, reach out to the experts instead.