Substrate Check

By Refilwe Hlungwani, MD

A useful note on substrate checks before coating, screed or repair work begins.

Failure usually starts in the slab, long before any coating or screed is mixed. Substrate Check looks at moisture in the concrete, weak surface laitance, cracking, oil or chemical contamination, and whether the base can carry the specified build. On South African sites, those checks often decide if preparation needs to change before bond and finish are put at risk.

This note stays close to what can be seen, tested and recorded on site. Gauteng dust, Durban humidity and Western Cape winter damp all change how concrete presents before repair or coating work starts. If this page fits your site, send the page slug through the contact form with a short site description.

Concrete conditions checked first

• Slab age and curing noted
• Photos of cracks, joints and damaged areas
• Specified system matched to substrate condition
• Site contact and work area named clearly

Read the related system information after this note. Substrate Check sets out what the base is doing on site, while the catalogue page deals with material build and use. That split helps teams compare product claims against the actual concrete in front of them.

First walk before preparation

Substrate Check focuses on what to verify before coating, screed or repair work starts. The note covers the slab condition, obvious defects and site factors that can affect bond and finish.

Start with the slab type, the service history and the available shutdown window. A warehouse bay, production area and wash-down zone can sit in the same plant while needing very different substrate decisions. Moisture migration, forklift traffic and cleaning chemicals all matter before preparation methods are chosen.

Take photos before grinding, chipping or washing changes the surface. Mark the bay, room or line number so defects can be tied back to the right area later. That record is useful when hollow spots, old repairs or hidden contamination only become clear after preparation begins.

Site factors that change results

Conditions around OR Tambo, Sunnyrock and Crown Mines can differ sharply from one building to the next, even within the same programme. Existing coatings, old patch repairs, movement at joints and heavy traffic patterns all affect what the slab is ready for. Separate urgent shutdown work from routine maintenance items so the inspection does not blur two different needs.

Coastal air can keep concrete wetter for longer, especially in enclosed areas with poor ventilation. Inland dust can mask weak surface zones until cleaning or grinding starts. Load-shedding also changes inspection timing where lighting, extraction or moisture testing equipment is part of the check.

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