Overview

The Dulux Avista Exposed Aggregate Surface Retarder is a ready-to-use, water-based retarder for freshly laid horizontal concrete. It delays the set of the surface cement paste so the stones underneath can be revealed with a simple wash-off, turning plain grey concrete into an exposed aggregate finish that is decorative and naturally slip resistant.

The 20L pail covers roughly 60 to 100 square metres of fresh concrete. A temporary blue tint shows where the product has been applied, so you do not miss a patch, and it fades after drying. The wash-off window sits between 3 and 24 hours, which gives flexibility for site scheduling.

Key Features

• Ready to use, no mixing or dilution needed
• Temporary blue tint confirms even coverage, fades after drying
• Water-based with low VOC and low odour
• Wash-off window of 3 to 24 hours after application
• Creates a rough surface that keys later pours or overlays
• Covers 60 to 100 m2 per 20L pail

Specifications

• Pack size: 20L pail
• Coverage: 3 to 5 m2 per litre, 60 to 100 m2 per pail
• Wash-off window: 3 to 24 hours
• Application: low-pressure garden sprayer, do not dilute
• Wash-off method: high-pressure water, minimum 2000 psi
• Chemistry: water-based retarder

Applications

• Exposed aggregate driveways
• Decorative pathways and footpaths
• Patios and outdoor entertaining areas
• Pool surrounds and coping
• Precast panels requiring an exposed finish

What You Need to Complete the Job

Finish the concrete, wait for the bleed water to disappear, then spray on the retarder and protect the surface from sun and rain. Wash off with a high-pressure sprayer the next day to reveal the stone, then seal with a Dulux Avista Exposed Aggregate Sealer for a wet-look finish or a Water Based Penetrating Sealer for a natural look. More tools and coatings live in the Concreting range.

Frequently Asked Questions

How soon after pouring do I apply the retarder?

Apply after the bleed water has gone and the glossy sheen has faded, but before the concrete reaches its initial set. In practical terms that is usually 30 minutes to 2 hours after finishing, depending on temperature and mix. Too early dilutes the product, too late gives a shallow, uneven exposure.

Can I leave the retarder overnight before washing?

Yes. The wash-off window runs from 3 to 24 hours, so washing the following morning is the normal plan. In cooler conditions below 20 degrees, aim for the longer end of the window. In hot or windy weather, check the surface sooner because the paste can harden beyond what a pressure washer will remove.

What aggregate size works best?

The retarder suits most standard decorative aggregates from 6mm river pebbles up to 20mm crushed stone blends. Finer aggregates of 6 to 9mm need a more careful application and are worth pre-testing, while larger 14 to 20mm stones are more forgiving and give a bolder finish. Always test a small section first.

Do I need to seal the exposed aggregate after washing?

Yes. Sealing is strongly recommended. Exposed aggregate traps dirt and stains more easily than a smooth surface, and a sealer protects it from weathering and makes it easier to clean. Allow the concrete to dry for 24 to 48 hours after washing before you apply the sealer.