Exposed aggregate concrete is one of the most popular decorative finishes for driveways, patios, pool surrounds, and paths, but getting a consistent result every time requires the right product and the right technique. Expoze Concrete Surface Retarder by Auseal takes the guesswork out of the process, giving you predictable, uniform aggregate exposure on every pour.
What Is Expoze Concrete Surface Retarder?
Expoze is a ready to use, water-based concrete surface retarder that delays the hardening of the top layer of freshly poured concrete. This controlled delay allows you to wash away the surface cement paste later, revealing the natural aggregate beneath for a clean, attractive exposed finish.
It's formulated with all-natural ingredients, is odourless, non-toxic, and environmentally friendly, making it suitable for a wide range of project conditions and aggregate types.
Key Features and Benefits
- Water-based orange colouring makes it easy to see where you've sprayed for even, consistent coverage
- Ready to use, no mixing required
- Odourless and non-toxic
- Non-polluting and environmentally friendly
- All natural ingredients, suitable for all natural aggregates
- Anti-corrosive
- Does not compromise the final strength of the concrete
- Economical application rate
- Superior, consistent results across varied project conditions
What You'll Need
- Expoze Concrete Surface Retarder
- Pressure sprayer
- Plastic sheeting or cover (for weather protection)
- 3,000–4,000 psi water blaster (for removal)
- PPE — gloves and eye protection
Step-by-Step Application Guide
Step 1 — Pour and Finish the Concrete
Pour and finish your concrete slab as normal. Allow the initial bleed water to evaporate from the surface before applying Expoze. Applying too early (while bleed water is still present) can dilute the product and affect performance.
Step 2 — Apply Expoze by Pressure Sprayer
Using a pressure sprayer, apply Expoze evenly across the entire concrete surface. The orange colouring helps you identify any missed spots and ensures uniform coverage.
Application rate: 300–400 ml per m² — adjust based on on-site conditions, aggregate type, and desired depth of exposure. Always conduct a site test first to dial in the right rate for your specific project.
Step 3 — Protect the Surface
Once applied, protect the treated surface from rain, dust, and other environmental contaminants. Cover with plastic sheeting if rain is forecast or conditions are dusty. Contamination during the retardation period can affect the consistency of the final finish.
Step 4 — Wait for Retardation (12–24 Hours)
Allow Expoze to work for 12–24 hours, depending on environmental conditions (temperature, humidity) and your concrete mix. Warmer conditions will accelerate the concrete set, while cooler or humid conditions may extend the window. Site testing is the best way to determine the right timing for your project.
In some cases, where the concrete allows, removal can be carried out on the same day.
Step 5 — Pressure Wash to Reveal the Aggregate
Once the retardation period is complete, use a 3,000–4,000 psi water blaster to hose off the surface. The retarded cement paste will wash away cleanly, revealing the natural aggregate beneath.
Simple rinsing or pressure washing is all that's needed, no harsh chemicals or scrubbing required.
Step 6 — Allow Normal Curing to Continue
After washing off the Expoze, the concrete continues its normal curing process. The final strength of the concrete is not compromised. Allow the slab to cure fully before sealing or applying any surface treatments.
Coverage Rate Summary
| Application Rate | Removal Timing | Pressure Wash PSI |
|---|---|---|
| 300–400 ml/m² | 12–24 hours (site dependent) | 3,000–4,000 psi |
Tips for Best Results
- Always do a test area on-site before treating the full slab — conditions vary between pours
- Apply after initial bleed water has evaporated for best adhesion and performance
- Ensure even spray coverage — the orange colour makes this easy to check
- Protect from rain and dust during the retardation period
- Adjust application rate based on aggregate size and desired exposure depth
Ideal Applications
Expoze is suitable for exposed aggregate finishes on:
- Driveways
- Patios and entertaining areas
- Swimming pool surrounds
- Paths and walkways
- Commercial and decorative concrete projects
