Concrete grinding covers two common jobs: stripping old coatings such as paint, glue and epoxy off a slab, and levelling or smoothing the concrete itself. The tooling differs for each. Coating removal wants an aggressive cutter that clears gummy material without clogging, while levelling wants a grinding cup that takes the high spots down evenly. This guide walks through what to use and in what order.
Two jobs, two tools
Before you buy anything, be clear which job you are doing. Removing a coating is about shearing a soft or brittle layer off the surface without the disc loading up. Levelling is about removing concrete in a controlled, flat pass. A tool that is brilliant at one can be poor at the other, so it pays to match the disc to the task. Both sit in the grinding category alongside the wider concrete tools range.
Stripping coatings: PCD tooling
For thick, gummy or stubborn coatings, polycrystalline diamond (PCD) is the tool of choice. PCD cutters shear coatings off the slab rather than trying to abrade through them, so they handle materials that would clog a standard diamond cup almost instantly. The PCD cup wheels for surface coating removal are built for exactly this, taking paint, adhesive residue and coatings back to bare concrete ready for the next finish.
PCD leaves a slightly textured surface, which is often what you want before a new coating keys in. If you need a smoother result afterward, follow up with a metal-bond grinding cup.
Levelling and smoothing: diamond grinding cups
Once the surface is stripped, or where the job is simply a rough or uneven slab, you move to diamond grinding cups. These come in single-row and double-row patterns. A single-row diamond grinding cup wheel is fast and coarse, ideal for knocking down high spots and aggressive stock removal. A double-row grinding cup spreads the cut across more segments, giving a smoother, flatter finish at a slightly slower removal rate.
A common sequence is to level with a single row, then refine with a double row before any polishing. Both screw straight onto an M14 angle grinder or polisher, so changeover is quick.
Turbo cups for rapid stock removal
Where you have a lot of material to take off fast, a turbo cup earns its keep. The turbo cup diamond grinding wheels use a continuous turbo rim on a lightweight aluminium body for rapid stock removal on stone and concrete. They are the tool for bringing a badly out-of-level slab down quickly before you switch to a row cup for the finish.
Controlled finishing with ceramic cups
Bare metal-bond cups remove material fast but leave a scratch pattern. When you want more control and a finer surface, a ceramic-bond cup helps. The diamond ceramic grinding cup wheel works like a metal-bond cup but with more control and less scratch pattern, which makes it useful for edge work on large floors or for controlled exposure of the surface before polishing.
Smoothing the action with resin-filled wheels
There is a middle ground between a bare cup and a polishing pad. A resin-filled diamond grinding wheel is a sintered metal-bond cup with the gaps resin-filled, which smooths out the action for jobs that need more control than a bare cup wheel. It still removes material on stone and concrete, but with a gentler feel that suits smoothing a surface rather than hogging it down.
Restoration and burnishing pads
On existing concrete and terrazzo floors that need bringing back rather than grinding flat, floor restoration pads do the refining work. The dry floor diamond restoration pads are made for concrete and terrazzo restoration, and there are wet floor restoration burnishing pads for working with water. These step in after the heavy grinding is done, refining the surface through the grits toward a restored finish.
Dust control is not optional
Grinding concrete dry throws out a large volume of fine respirable dust. The cleanest way to work is to capture it at the disc. A Vortex dust extraction guard fits a 115mm or 125mm grinder and shrouds the cup, drawing dust straight into a connected vacuum so the bulk of it never reaches the air. Pair the guard with a suitable vacuum and you keep the floor visible, the finish cleaner, and the dust under control. There is more on dust and silica safety in our dedicated guide.
Grinder or floor machine?
For small areas, edges, steps and tight corners, a cup wheel on a hand-held angle grinder is the practical tool, and it reaches places a walk-behind machine cannot. For large open floors, a dedicated floor grinder covers ground faster and leaves a flatter result because its weight and multiple heads keep the cut even. Many jobs use both: the floor machine for the field, the hand grinder for the perimeter and the corners the big machine leaves behind. Whichever you use, the disc types and the order of work stay the same.
A sensible grinding sequence
For a typical coated, uneven floor: strip the coating with PCD, knock the high spots down with a turbo or single-row cup, refine with a double-row or ceramic cup, then move to resin polishing pads if a polished finish is the goal. Keep the grinder moving in overlapping passes, never dwell in one spot, and let the diamond cut at its own pace. Leaning on the tool only generates heat and uneven wear.
Check your progress as you go rather than at the end. A floor that looks flat to the eye can still hold low spots that only show up once a coating or polish is applied, so a straight edge laid across the slab between passes is worth the few seconds it takes. Catching a dip early means one more grinding pass, not stripping a finished surface back to start again.
FAQ
What removes epoxy or paint from concrete fastest?
PCD cup wheels are the most effective for thick or gummy coatings because they shear the coating off rather than abrading through it, which stops the disc from clogging. They take paint, glue and epoxy back to bare concrete ready for re-coating.
What is the difference between single-row and double-row grinding cups?
A single-row cup is coarser and faster, ideal for aggressive stock removal and knocking down high spots. A double-row cup spreads the cut over more segments for a smoother, flatter finish, so it is the better choice for refining after a first pass.
Do diamond grinding cups fit a standard angle grinder?
Yes. M14 grinding cups screw directly onto the spindle of a standard 115mm or 125mm angle grinder or polisher, so you can grind concrete without a dedicated floor machine for smaller areas and edge work.
Can I grind concrete dry?
You can, but dry grinding produces a lot of fine dust, so you must capture it with an extraction guard connected to a vacuum. Working dry without extraction is unsafe because of the respirable dust it creates.
How do I avoid leaving swirl marks?
Keep the grinder moving in overlapping passes rather than dwelling in one place, and step through the grits in order. A ceramic-bond cup leaves less scratch pattern than a bare metal cup when you need a finer surface before polishing.
What order should I grind a coated, uneven floor?
Strip the coating with PCD first, take down the high spots with a turbo or single-row cup, refine with a double-row or ceramic cup, then move to polishing pads if you want a polished finish.
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