Floor Scarifier vs Grinder: What's the Difference?

Scarifiers and grinders both prepare concrete surfaces, and both are core to the Trelawny range, but they remove material in different ways and leave different results. Choosing the wrong one is one of the most common surface preparation mistakes on site.

How a Scarifier Works

A scarifier uses a rotating drum fitted with tungsten-carbide flails that impact the surface, fracturing and removing material in a single aggressive pass. It removes more material, faster, and leaves a rougher, more heavily keyed profile.

How a Grinder Works

A grinder uses diamond-segmented discs that abrade the surface rather than impact it. It removes less material per pass, but produces a smoother, flatter, more consistent finish.

Side-by-Side Comparison

 

Factor	Scarifier	Grinder
Material removal rate	Fast, aggressive	Slower, controlled
Resulting profile	Rough, heavily keyed	Smooth, even
Best for	Coating removal, thick screeds	Thin coatings, polishing, levelling
Typical depth	Greater removal depth	Shallow, fine removal

 

When to Use Both

On many jobs, a scarifier does the bulk removal and a grinder finishes the surface to the flatness and profile the new coating requires. This two-step approach is common on large commercial floors moving from an old coating to a new thin-film system.

See the full Trelawny range: Floor Scarifiers and Floor Grinders