Shot blast or grind: the surface profile a traffic coating needs
The parkade preparation crew has finished a drive aisle. It appears evenly grey, but the foreman cannot find a record of the specified profile or the former surface treatment. The coating crew is waiting with primer, and the superintendent needs a clear substrate handover.
A uniformly coloured slab is not evidence that the required preparation is complete. The cited coating documents identify particular concrete-profile requirements and removal of materials that interfere with bonding. Compare the actual system criteria and substrate condition through the competent preparation team. Keep profile, cleanliness and moisture as separate handover questions; one does not prove the others.
Accept the prepared substrate by zone
- Bring the correct acceptance references. Identify the approved coating documents, required profile and project inspection arrangement. Confirm how the team will compare and record the result. Resolve conflicting requirements with the technical contact rather than picking the easiest number from another system.
- Investigate what is on the slab. Give the preparation lead available records of sealers, curing materials, old coating, contamination and previous repairs. Record uncertain areas. Ask for the required investigation or trial instead of assuming mechanical roughening removes every incompatible material.
- Coordinate an assessed preparation method. Have competent people select equipment and controls for the actual substrate, services, exposure and occupied conditions. Confirm safe boundaries and adjacent protection. The desired profile does not, by itself, authorize a machine or its operating settings.
- Review an agreed trial area. Locate the trial and check the required profile, residual material, cleanliness and substrate condition through the approved process. Record observed limitations and any required adhesion or further assessment. A representative trial makes the acceptance expectation visible before the full level is prepared.
- Record the actual zone handover. Identify where preparation is complete, who reviewed it and which exceptions remain. Retain relevant photographs and inspection evidence. Keep questionable repairs or contaminated patches out of the released area instead of concealing them beneath the primer.
- Protect acceptance until coating starts. Coordinate following work, dust, water and traffic that can change the prepared surface. Have the coating lead confirm readiness at the actual start. If another activity affects the zone, record the change and obtain the required reassessment rather than relying on the earlier sign-off.
Common mistakes
- Using uniform colour as the profile inspection.
- Treating roughness as proof that contamination is gone.
- Assuming an accepted surface stays ready through later traffic and washing.
Checklist
A clear preparation handover
- Actual system criteria available.
- Existing surface materials investigated.
- Competent method and site controls.
- Located trial and acceptance evidence.
- Zone limits and unresolved exceptions.
- Start-of-coating readiness confirmed.
Check your understanding
The profile appears acceptable, but a prior sealer is still an unresolved question. Should the whole aisle receive primer?
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