1) Establishing the Baseline: Coating, Substrate, and Adhesion

Start with a short diagnostic. You need only three facts to narrow the method: (a) coating type and thickness, (b) substrate, and (c) adhesion strength. For a coating‑type refresher and what tends to clog vs. fracture, see What Types of Coatings Can Be Removed with Diamond Tools?

• Common coatings: paint & adhesives (thin), epoxy/polyurethane (medium to heavy build), elastomeric membranes (flexible), traffic toppings (abrasion‑resistant).
• Quick thickness check: score a small patch—if you can lift a film, you’re in thin‑coat territory; if it chips, likely a brittle build; if it stretches, it’s elastomeric.
• Adhesion: core with a utility blade or use a pull‑off test—weakly bonded films grind fast; well‑adhered epoxies often require scarifying or staged removal.
• Substrate sensitivity: concrete tolerates profiling; granite/marble require controlled aggression; metals demand corrosion‑aware media and low heat input.

2) Methods Compared: Mechanical, Chemical, Thermal, Abrasive

2.1 Mechanical

Mechanical methods dominate concrete projects because they are measurable, dust‑collectable, and predictable. The four main families are diamond grinding, bush hammering, scarifying, and shot blasting. For a deeper tour of technique pros/cons, also see 5 Advanced Methods for Removing Coatings from Concrete.

Diamond Grinding

• Best for: thin to medium coatings, adhesive residues, leveling prior to polish or overlay.
• Segments: soft‑bond segments for hard floors; open‑matrix patterns reduce loading on gummy residues.
• Productivity (indicative): 20–50 m²/hr with a 680–780 mm planetary grinder + HEPA extraction.
• Finish: CSP 1–3; excellent control on final flatness.

Bush Hammering

• Best for: brittle coatings, texture creation for anti‑slip or overlay keys; also for stone texturing.
• Tooling: multi‑roller plates with carbide pins; pin count and spacing control bite and texture depth.
• Productivity: 15–30 m²/hr on floor grinders; higher with wide heads and stabilized machines.
• Finish: CSP 3–5 typical; uniform macro‑texture without deep gouging when set correctly.

If you’re new to bush hammering or want a usage primer, read How to Use a Bush Hammer on Concrete Floors.

Scarifying (Planing/Milling)

• Best for: heavy builds (thick epoxy, urethane mortar), ceramic tile thinsets, and severe contamination layers.
• Cutters: flails, beam‑style carbide; drum speed and cutter spacing set aggression.
• Productivity: 20–40 m²/hr; fastest on thick, brittle systems.
• Finish: CSP 4–8 depending on cutter selection; plan to follow with grinding if a lower CSP is required.

Shot Blasting

• Best for: large, open areas needing consistent profile and embedded contaminant removal.
• Media: steel shot size controls profile; machine feed rate and amperage tune depth.
• Productivity: 40–80 m²/hr; integrated recovery leaves a dry, clean profile.
• Finish: CSP 3–7; highly uniform if travel lines overlap correctly.

2.2 Chemical Stripping

Useful where dust must be minimized or near sensitive equipment. Select solvent, alkaline, or low‑VOC biodegradable strippers per resin chemistry. Always plan for dwell time, neutralization, and waste handling. Expect a mechanical pass afterward to standardize profile.

2.3 Thermal

Infrared/hot‑air softening or controlled flame can release certain paints and membranes. On concrete, heat can drive oils deeper; on metal, avoid warping. Treat as a pre‑step before scraping and finishing.

2.4 Abrasive (Including Wet/Dry Ice)

From sand and garnet to soda, sponge, and dry ice, blasting excels on steel, complex geometries, and detailed edgework. Water injection reduces dust but requires slurry management. Profiles depend on media hardness, size, and pressure.

3) CSP Targets and Finish Planning

The Concrete Surface Profile scale (CSP 1–10) links removal method to coating performance. Align the method to the required re‑coat system:

4) A Practical Decision Framework

1. Identify coating & thickness: brittle (chip) → mechanical fracture; gummy (smear) → open‑pattern grinding + solvent wash; flexible membranes → staged peeling + low‑speed milling.
2. Check substrate constraints: decorative stone → controlled diamond passes; metal → media choice to avoid undercut corrosion; concrete → any, as CSP demands dictate.
3. Set CSP target by re‑coat system (see table above).
4. Choose the fastest method that still meets CSP (e.g., scarify then grind rather than grinding everything).
5. Plan dust/liquid management (HEPA extraction, wet slurry capture, neutralization for chemical residues).
6. Pilot 1–3 m², confirm removal rate and finish, then lock settings and document.

5) Field‑Proven Workflows (4 Scenarios)

Scenario A — 2 mm Warehouse Epoxy, Re‑coat with Standard Epoxy

Goal: Efficient removal and CSP 3 finish.

1. Edge cut with 5–7" grinder (open‑matrix diamond).
2. Main field: scarifier with medium drum at conservative depth; vacuum shroud active.
3. Follow with 30/40‑grit diamonds to flatten peaks to CSP ~3.
4. Dust verification: white rag test; spot re‑grind as needed.

Notes: This two‑step plan is usually faster than grinding the full thickness. If adhesion was weak, you may skip scarifying and proceed with aggressive diamonds.

Scenario B — Elastomeric Deck Membrane, Occupied Building (Low Dust)

Goal: Remove flexible membrane with minimal disturbance.

1. Score and peel large sheets; collect immediately.
2. Apply low‑odor stripper to residue, allow dwell; scrape.
3. Rinse/neutralize; final pass with fine grinding to CSP 2–3.

Notes: Plan waste containers ahead; ensure neutral pH before recoating.

Scenario C — Anti‑Slip Upgrade on Exterior Granite/Concrete

Goal: Durable texture with uniform aesthetics.

1. Test patch with bush hammer plates: start conservative roller spacing.
2. Dial in pass speed and head pressure to hit CSP 4–5 without edge chipping.
3. Rinse or vacuum dust; seal or overlay as specified.

Notes: For background on bush hammering principles and use cases, read What Is a Bush Hammer and What Is It Used For?

Scenario D — Heavy Urethane Mortar in Food Plant (Hygiene Constraints)

Goal: Fast removal, controlled debris, and CSP 5+ for new system.

1. Scarify to near substrate with drum containment.
2. Shot blast to achieve uniform CSP 5–6.
3. QA pull‑off test on representative zones; patch voids.

Notes: Coordinate with sanitation for debris control and schedule post‑blast cleaning ahead of coating crews.

6) Productivity, Cost, and Risk Matrix

Blended plans (e.g., scarify → grind) often deliver the lowest total hours at the required CSP. Pilot testing keeps risk and rework low.

7) Safety, Dust, and Waste Management

• Silica dust: use HEPA vacs, sealed hoses, and automatic filter cleaning; wet cuts where appropriate.
• Chemicals: observe SDS, ensure active ventilation, neutralize/confirm pH before handover.
• Noise/vibration: plan shift rotations and hearing protection; bush hammer/scarify cycles benefit from stable feed rates to reduce vibration.
• Waste: segregate solids, liquids, and contaminated media; document volumes and disposal route.

8) QA Checklist and Handover Docs

1. Record coating ID, thickness, and substrate notes; photos of test patches.
2. Log settings: machine model, head pressure/speed, segment/bush pin spec, blast media size.
3. Confirm CSP via comparator chips; capture macro photos with scale.
4. White rag dust test and adhesion spot checks; note corrective passes.
5. Handover pack: CSP confirmation, cleaning/neutralization logs, waste manifest, re‑coat window.

9) Mini‑FAQ

Do I always need a chemical step? No. Use chemicals mainly for flexible films, sensitive environments, or when dust is restricted. Expect a light mechanical pass afterward.

Can bush hammering replace shot blasting? For many exterior anti‑slip or overlay keys—yes. For deep anchor profiles on heavy builds, shot blasting or scarifying may still be faster.

Where should I start if time is tight? Pilot 1–3 m² with your fastest likely method; measure m²/hr and CSP; lock settings; scale confidently.