If you’ve ever prepared a concrete floor for coatings, overlays, or adhesives, you’ll have come across the term Concrete Surface Profile (CSP). But what does it actually mean, and why do specifiers insist on it?
In this guide, we’ll explain what CSP is, how it’s measured, and why shot blasting is one of the most reliable methods for achieving the correct profile.
What is a CSP?
A Concrete Surface Profile (CSP) is a scale from CSP 1 (nearly smooth) through to CSP 9 (very rough and deeply textured). It’s defined by the International Concrete Repair Institute (ICRI) as a way to measure surface roughness and porosity.
- Low CSP (1–3): Suitable for thin coatings, sealers, and paints.
- Medium CSP (3–6): Required for thicker coatings, self-levellers, and epoxy floors.
- High CSP (6–9): Needed for overlays, heavy-duty toppings, or repair mortars.
Why CSP Matters
Coatings, resins, and adhesives rely on a mechanical bond to the concrete surface. If the surface is too smooth, coatings may delaminate. If it’s too rough, you may use excessive product.
That’s why specifiers and manufacturers often stipulate the required CSP level in their application guides. Achieving the right profile ensures:
- Maximum adhesion
- Long-term performance
- Reduced risk of costly failures
How to Achieve the Correct CSP
Different preparation methods produce different CSP levels:
- Grinding: Best for CSP 1–3 (fine finishes).
- Shot Blasting: Ideal for CSP 3–6 (most common for coatings and resins).
- Scabbling or Scarifying: Used for CSP 6–9 (very rough, heavy removal).
Shot blasters are the go-to solution for most flooring contractors because they create a uniform, dust-free profile in line with CSP specifications.
Crucial Tip: Controlling the Shot Blast Profile
Shot blasting is favoured for its precision and consistency. With a professional Contec mobile shot blaster, you control the final CSP by adjusting three variables:
- Shot Size – smaller shot produces a finer profile, while larger shot creates a rougher texture.
- Shot Volume (Flow Rate) – higher flow increases cutting action and depth.
- Machine Speed – slower travel increases dwell time, cutting deeper; travelling too slowly risks gouging the surface, while going too fast may leave the concrete under-prepared and coatings poorly bonded.
Troubleshooting Tip: If your profile comes out finer than expected (e.g., you aimed for CSP 5 but achieved CSP 3), the most common causes are excessive travel speed or low abrasive flow rate (media valve or shot supply).
Operator Safety Tip: Never leave the machine standing still with the blast wheel running at the end of a pass. Residual shot in the wheel can discharge and blow a hole in the floor, causing costly damage and rework.
Next-Level Issue – The Carpeting Effect: Another common problem is visible striping or banding, known as the carpeting effect. This results from uneven passes or inconsistent overlap. We’ll cover how to prevent it in a dedicated guide.
PWM Sales & Contec Shot Blasters
At PWM Sales, we supply the full Contec range of mobile shot blasters designed to deliver CSP profiles consistently.
- Elephant units – compact, ideal for achieving CSP 3–4 for thin resin coatings.
- Modul 200/300 models – versatile for CSP 3–5, handling medium resin floors and epoxy coatings.
- Modul 350 – recognised as the best for steel, but also effective for CSP 4–5 on demanding substrates.
- Elgator machines – high-output, wide working width units for consistent CSP 4–5 on large epoxy floor projects.
Our systems are guaranteed to deliver uniform CSP profiles dust-free, provided they are used with a certified H-Class extractor, which is mandatory for HSE/OSHA compliance when dealing with crystalline silica dust from concrete.
Explore our Contec Mobile Shot Blasters:
Conclusion
Understanding and achieving the correct CSP is critical to any successful floor preparation project. With the right Contec shot blaster and certified H-Class dust control system, you can confidently hit the required profile — ensuring coatings, resins, and overlays perform exactly as intended while staying fully compliant with health and safety regulations.