Mechanically polished Concrete/MPC Guidelines/Slab Quality

⚠️ The Reality of Premium Concrete Polishing

Pour Quality Dictates Finish: A premium mirror reflection relies entirely on uniform stone distribution and high cement paste density.
Avoid Poor Mixes: Local mix issues—like poor aggregate grading, soft limestone cement, unwashed sands, or crusher dust—will cause the surface chemistry to fail.
Machinery Follows the Slab: Mechanical polishing does not flatten a wavy floor. Our machinery contours to the existing profile of your concrete.

📐 Floor Flatness Tolerances (The 3mm Rule)

The Specification: In line with Australian commercial construction guidelines, the raw slab must have a maximum deviation of no more than 3mm over a 3-metre straightedge.
Impact on Exposure: Dips and humps cause planetary grinders to hit high spots heavily (creating patches of full stone exposure) and float over low spots (leaving zero stone or “ghosting”).
Rectification: Slabs poured out of tolerance will require extensive, costly remediation grinding to fix the footprint before polishing can begin.

🧪 New Slabs: Mix Design & Pre-Pour Specs

To achieve a successful mechanical polish, your concrete supplier must follow these exact mix rules:

Cement Selection: Use Type GP (General Purpose Cement) only.
Compressive Strength: Minimum 32 MPa structural mix required (40 MPa highly recommended for zero-stone or nil-exposure finishes).
Zero Crusher Dust: The mix must use clean, washed sharp sands. Crusher dust destroys cement density, absorbs excess water, and leaves a dead, micro-pitted surface that cannot take a crisp polish.
Water Control: Avoid diluted cement paste. Too much water sinks the stone to the bottom mesh and leaves a weak, dusty “cream” surface layer.
Chemical Controls: Use controlled water-reducers only. Strictly no heavy overdosing of superplasticisers or fluidisers to force an easy pour, as this separates the mix.

🚫 Curing & Chemical Warning

No Third-Party Products: Do not apply any retail curing products, chemical compounds, or off-the-shelf sealers without consulting us first.
The Risk: Retail products create permanent surface barriers that block the liquid densifiers and chemical hardeners we inject, effectively ruining the refinement process.