Single-Disc Concrete Grinders

A single-disc concrete grinder is a machine with one working head that presses a diamond segment against the floor and grinds the surface with a rotating motion. A multi-disc (planetary) machine has a main disc with 3 counter-rotating satellites — smaller plates carrying segments — which produces a flatter floor on large surfaces above 100–200 m². A single-disc unit, with its single head and a weight usually up to a few dozen kilograms, is lighter, cheaper and reaches edges and corners more easily, which is why it suits renovations and rooms up to about 100 m².

The difference lies in the head design: a planetary grinder has a main disc with 3 counter-rotating satellites, so it covers a wide swath of floor in a single pass and works best on surfaces above 100–200 m² and for polishing up to a grit of 400–3000. A single-disc grinder has one head, typically 180–300 mm in diameter, and is lighter and more maneuverable, so it performs better in renovations, smaller rooms up to about 100 m² and along edges. In practice, the two types often complement each other on the same site.

Single-disc concrete grinders are used mainly for stripping old coatings, paint, adhesives and cement laitance with a coarse segment of grit 16–30, for levelling minor floor irregularities before self-levelling compounds or resins (grit 40–70), and for grinding edges and corners a planetary machine cannot reach. They work well in rooms up to about 100 m² — bathrooms, garages, corridors — and for spot repairs on industrial floors. The range includes, among others, the EX250L model with a 250 mm working disc, a typical example of this machine class.

The standard on single-disc concrete grinders is a working disc of roughly 180 to 300 mm in diameter — a range that includes, for example, the EX250L model offered at NORWIT.PL with a 250 mm disc. Smaller diameters (180–200 mm) make it easier to reach edges and corners, while larger ones (250–300 mm) increase output on open floor at a similar machine weight. The choice of diameter depends on the nature of the job — renovation, refurbishment or preparing a substrate for a self-levelling compound.

A single-disc concrete grinder handles coatings, paint and mounting adhesives well, provided a coarse segment of grit 16–30 is used, which typically removes 1–3 mm of material in a single pass. Thicker build-ups, in the order of a dozen to 20 mm, should first be removed with a concrete milling machine, with the grinder used only at the finishing stage — levelling the surface after rough milling. After stripping a coating, it's worth going over the floor with a grit 40–70 segment to prepare the substrate for a new screed, resin or adhesive.

NORWIT.PL stocks single-disc concrete grinders primarily from Dr. Schulze, Husqvarna Construction and Schwamborn — with working discs typically in the 180–300 mm range and diamond segments from grit 16 to 70 for rough and levelling work. Machines from these manufacturers are available on the Dr. Schulze and Husqvarna Construction brand pages. For larger floors and polishing above a grit of 100, we recommend the planetary machines in a separate category.

Dry grinding with a single-disc concrete grinder requires a class M or H industrial vacuum with a capacity of at least 200–400 m³/h, coupled to the head shroud. This follows from the occupational exposure limit for the respirable fraction of crystalline silica dust, set at 0.1 mg/m³ — without extraction, this dust is harmful to the lungs under prolonged exposure. The alternative is wet grinding, used less often with single-disc machines than with planetary polishing. Suitable models are in the vacuums for grinders category.

A single-disc concrete grinder typically starts at a few thousand zloty and rises to over a dozen thousand for stronger models — lower than planetary machines, which weigh several hundred kilograms against a few dozen for a single-disc unit. Renting one for a single job typically costs 100–300 PLN per day plus a deposit and consumed segments. Buying pays off for companies doing floor renovation and repair regularly, since the cost is recovered after a handful of jobs; current prices are on the product pages.