Cured, unsealed exposed aggregate concrete
Ensure concrete is sufficiently cured (recommended minimum 14 days). Concrete is to be clean and free of grease, oil, paint or any curing agent. Stiff broom and general purpose cleaner recommended. Any oil stains should be treated & cleaned with an industrial degreaser. Pressure clean surface at minimum 2000 psi and allow to dry. Acid etch with hydrochloric acid. Dilute approximately 20 parts water to 1 part acid (depending on porosity) to remove any loosely bound cement and laitance. Apply diluted acid to surface using a large head watering can, applying in a criss cross motion (approximately 5-10m² sections). Acid will start to fizz on the surface once it starts to react with the laitance in the concrete. Pressure clean immediately to clean and remove all remnants of acid (do not allow acid to dry on surface). Pressure clean at minimum 2000 psi. Allow surface to dry before sealing (sealing over damp concrete will cause whitening).
Note: Acid etching should always begin at the lowest point of the surface & proceed uphill.

Previously sealed exposed aggregate concrete
Concrete is to be clean and free of grease, oil and any other contaminants. A stiff broom and general purpose cleaner are recommended. Pressure clean at minimum 2000 psi to clean and remove all contaminants. Allow surface to dry before resealing (sealing over damp concrete will cause whitening). Once dry, surface must be treated with solvent to reactivate the existing sealer & form a bond. This will help with the adhesion of the new sealer coat. Apply Dulux Avista Solvent to the area being resealed using a roller and roller tray or broom.
Allow area to dry enough to walk on before proceeding with sealer application.

Freshly laid exposed aggregate concrete
The surface must be sufficiently dry and firm enough to walk on without marking and there mustn’t be any free water present. Sealer must be applied within 24 hours of the aggregate being exposed/retarder wash off occurring. If greater than 24 hours has passed since the aggregate was exposed, the surface should then be allowed to cure for a minimum of 14 days & prepared as per instructions below.

Sealer to be applied by a suitable solvent resistant broom or 15mm-22mm nap roller. Roller used will depend on the profile of the exposed aggregate concrete.
The sealer must be mixed prior to application using a stirrer or paddle.
To apply sealer, pour sealer into a roller tray, and evenly roll or broom onto the surface.
Ensure sealer is not applied too thick and no pooling occurs as this may cause bubbling.
Avoid excess sealer build up on the edges of the roller. This can lead to roller lines in the surface.
An additional coat of sealer can be applied after a minimum of 2 hours.

Drying time: Minimum of 2 hours between coats when applied at 25°C and above at 50% relative humidity. Recoat times will be longer in cooler weather (<25°C) or higher humidity. Do not apply sealer at temperatures below 8°C or above 35°C.><25°C) or higher humidity. Do not apply sealer at temperatures below 8°C or above 35°C.