Advice Hub · Grinders
Concrete prep and levelling without the silica dust hazard
The Festool concrete levelling system pairs the RG 130 renovation grinder with M-class extraction and a cyclone pre-separator for taking down concrete high-spots, paint, and surface laitance with respirable crystalline silica captured at the source.
Levelling concrete - knocking down high spots on a slab, removing surface laitance before a topping or coating, taking off old adhesive or paint is one of the more hazardous tasks for the construction trades. Dry grinding concrete generates respirable crystalline silica (RCS), and the long-term health effects of silica exposure are well-documented and severe.
In Australia, workplace exposure standards for RCS are tight, and enforcement is increasing. Worksafe authorities have issued substantial penalties for silica-related breaches in recent years. For concreters working on slabs, levelling pads, or surface preparation ahead of coatings, the question isn't whether to use dust extraction, it's whether your extraction setup is genuinely capturing the fines at source, or just moving most of the dust around the site.
The Festool concrete levelling system is built around the RG 130 ECI renovation grinder, paired with a diamond disc, an M-class AutoClean extractor, and a cyclone pre-separator. The combination captures high-volume concrete waste at the disc and protects the extractor's filter from being overwhelmed which is what keeps suction at full strength across a whole slab rather than dropping off after the first few square metres.
The tool: RG 130 ECI renovation grinder
The RG 130 ECI is a 130 mm brushless renovation grinder built for aggressive material removal on concrete, screed, and hardened coatings. Three design choices matter most for concrete levelling work:
- Integrated extraction shroud. The disc runs inside a sealed shroud connected to the extractor port. Unlike conventional angle grinders fitted with aftermarket dust shrouds, the RG 130's shroud is engineered as part of the tool — the seal against the slab is consistent, the airflow path around the disc is calculated, and dust is pulled directly into the extractor rather than escaping around the edges.
- Brushless motor with constant-speed electronics. Concrete loads the disc heavily, especially on high spots and laitance removal. The electronic controls maintain disc speed under load, which means consistent material removal rate and predictable behaviour rather than the bogging-down that throws off a single-pass levelling job.
- Accepts 130 mm diamond and abrasive discs. Diamond hard for concrete levelling and laitance removal; diamond soft for harder substrates; abrasive discs for paint and coating removal. One tool, multiple applications.
The extraction: CTM 36 AC AutoClean M-Class
Concrete grinding generates the highest-volume, hardest-on-filter dust load in the trades. A standard M-class extractor without filter cleaning will clog within minutes on a concrete slab, dropping suction to a fraction of its rated capacity which means the dust you can't see is the dust your extraction is no longer capturing.
The CTM 36l M-Class EI AutoClean Dust Extractor solves this with automatic filter pulsing. Every 15 seconds, the AutoClean system pulses the filter to dislodge the dust cake. Suction stays close to rated capacity across an entire slab — not just for the first square metre.
It is a certified M-Class extractor, retaining at least 99.9% of dust with occupational exposure limits in the medium-risk category. For respirable crystalline silica specifically, the combination of M-class filtration, AutoClean filter pulsing, and the cyclone pre-separator (below) is what turns concrete grinding from a hazardous job into a managed one. Note: M-class is the minimum specification for silica-generating work; specific job sites may require H-class equipment depending on substrate, duration, and local risk assessment, please check your site's requirements.
The RG 130 concrete grinder is rated at 1600W which means at full power with a dust extractor in series, it will draw more current than should be applied to a mains socket. The dust extractor therefore has a safety feature when tools are plugged directly into it to operate at 1200W or less. To work as a harmonious system, the concrete grinder has an integrated Bluetooth that can be paired to turn the Dust extractor on and off, rather than relying on the tool being plugged into the front of the extractor.
The consumables for concrete: Plastic Waste Bags for CT 36 AC filter bags
Concrete fine dust fills an extractor bag fast. A 36-litre extractor running on a slab might fill a bag in an hour of continuous grinding and once the bag is full, both suction and filter cleaning effectiveness drop sharply.
The Replacement Plastic Waste Bags for CT 36 AC (5-pack) are the right consumable to stock at trade quantity. The plastic waste bag is the best choice since, whilst the fleece ones can be used, are more likley to clog: as the extractor cycles on and off, the bag flexes and the dust cake on the inside filter is shaken loose and drops into the plastic wate bag. That means the bag holds close to its rated suction for longer, and it doesn't clog catastrophically the way a paper bag does on fine concrete dust. Carry a five-pack, at trade consumption rates on slab work, you'll use them.
The accessory: Premium Hard Diamond Grinding Disc 130 mm
For concrete levelling specifically, the right disc is a hard-bond diamond. The bonding matrix of the disc has to be hard enough to wear back evenly as the diamonds dull, exposing fresh diamond at the surface — but not so hard that the diamonds glaze over and stop cutting.
The Premium Hard Diamond Grinding Disc 130mm is engineered to match the RG 130's speed and torque profile. It produces an aggressive cut on cured concrete, takes down high spots and surface laitance predictably, and lasts significantly longer than a generic diamond disc on the same job. For concrete levelling work where a single disc may need to handle a full slab, the Premium Hard is the right specification — generic discs glaze faster and need more frequent dressing or replacement.
The extraction management: CT-VA Cyclone Pre Separator
Concrete dust is hard on extractor filters. The heavy material — chips of paint, slurry, larger concrete particles — should never reach the filter at all. That's what a cyclone pre-separator is for.
The CT-VA Cyclone Pre Separator sits between the RG 130 and the CTM 36 AC. The grinder's hose connects to the cyclone's inlet; the cyclone's outlet connects to the extractor. Air spirals around the inside of the cyclone, the heavy material drops into the collection container at the base, and only the fine dust continues on to the extractor's bag and filter.
On a long concrete-grinding session, the cyclone does two important jobs. First, it keeps the extractor's filter bag empty for longer — most of the volume goes into the cyclone's bin, not the bag, so you replace bags far less often. Second, it dramatically reduces filter loading, which means the AutoClean filter pulsing has less work to do and overall suction stays higher across the job. For trade-volume concrete work, the cyclone pre-separator is what makes the whole system viable across a full day.
Why three-stage capture matters for silica
Concrete grinding generates respirable crystalline silica — particles small enough to penetrate deep into the lungs. A managed three-stage capture system addresses the three different ways this dust escapes.
- Stage 1 — capture at the disc. The RG 130's integrated shroud seals against the slab and pulls dust into the airflow before it can escape sideways. This is the only stage that prevents airborne silica forming in the first place.
- Stage 2 — separation in the cyclone. Heavy material drops out before reaching the extractor's filter. Filter loading drops dramatically, so the extractor maintains rated suction throughout the job rather than choking after the first slab area.
- Stage 3 — M-class filtration with AutoClean. The fine respirable dust that does reach the extractor is captured at 99.9% retention. AutoClean pulses the filter every 15 seconds so that capture rate doesn't drop as the bag fills.
- Result. A system that genuinely captures respirable silica at source, rather than just visible chips. The aim isn't a clean-looking site — it's a clean-air site.
Why the concrete levelling system matters for your business
- Silica capture you can demonstrate. A three-stage capture system with documented M-class filtration is what compliance officers and main contractors are looking for. The system is auditable: integrated shroud, cyclone pre-separator, certified M-class extractor.
- Continuous suction across a full slab. AutoClean filter pulsing plus the cyclone keep the extractor running close to rated capacity for the duration of a job, not just the first few minutes. That means the dust you can't see is still being captured at the end of the day.
- Long disc life on cured concrete. The Premium Hard Diamond disc paired with the RG 130's constant-speed electronics lasts significantly longer than generic discs on the same job — fewer disc changes, more time grinding.
- Healthier sites win more work. Increasing numbers of main contractors specify silica-managed subcontractors only. A documented capture system isn't just compliance — it's a tendering advantage.
