Concrete Surface Preparation Standards Explained

Most coating and overlay failures trace back to one thing: the surface profile underneath was not right for the product applied on top. The International Concrete Repair Institute (ICRI) defines this profile on a numbered scale, commonly referenced by coating manufacturers, specifiers, and contractors as the Concrete Surface Profile, or CSP.

What CSP Measures

CSP describes the texture and roughness of a prepared concrete surface, from CSP 1 (near-smooth) to CSP 9 (very rough, deep exposed aggregate). Coating and overlay manufacturers specify a target CSP range for their product because adhesion, and therefore performance, depends on it.

Why It Matters

A surface prepared to too low a profile gives thick overlays and screeds nothing to mechanically key into, risking delamination under load or thermal movement. A surface prepared too aggressively can telegraph through thin coatings or waste material filling an unnecessarily rough profile. Matching equipment and technique to the specified CSP is a specification requirement on most commercial and infrastructure projects, not just good practice.

Achieving the Right Profile

 

CSP Range	Typical Finish	Suitable Equipment
CSP 1–3	Light texture, thin coatings	Grinding
CSP 3–5	Medium texture, general coatings	Scarifying / light scabbling
CSP 5–9	Heavy texture, overlays and screeds	Scabbling

 

For guidance on matching a specific project to the right Trelawny machine, see our equipment selection guide. [Link: /how-to-choose-surface-preparation-equipment/]