ProJoint PolySweep Polymeric Brush In Sand 20kg

ProJoint PolySweep is a premixed polymeric jointing sand designed specifically for filling joints in block paving, natural stone, concrete slabs and setts. Unlike standard kiln-dried sand, it contains advanced binding agents that activate on contact with water, helping the joints to harden and resist washout, weed growth and frost damage once cured. Its clear-set technology means it cures without staining the paving surface. The brush-in application method is straightforward and requires no mixing – the product is swept into the joints dry, compacted and then activated with water. It is suitable for joint widths from 1mm upwards, making it well suited to the narrow, uniform joints typical of block paving, and contains no Portland cement.

Thorough preparation is important for long-term performance. The paving joints must be clean and dry to a minimum depth of 20mm – remove all existing jointing material, weeds, debris and organic matter before starting. The surface and joints must be completely dry at the time of application, and there must be no risk of rainfall for at least 12 hours after installation. If rain is forecast, cover the completed area immediately with a tarpaulin until the risk has passed and remove it as soon as conditions allow. Do not apply when the average air temperature is below +5°C, and ensure temperatures will remain above +5°C for at least 48 hours after installation. A whacker plate is recommended before activating with water to compact the product firmly into the joints and improve the final bond.

PolySweep cures by drying out – water absorbed into the joints during activation must be able to drain away freely through the sub-base. If the bedding mortar is impermeable, water becomes trapped in the joints, which slows curing, can soften the binder over time and encourages algae growth. A permeable bedding mix is defined as a ratio of 5:1 sand to cement or leaner, or a purpose-made permeable bedding mortar. A standard 4:1 or 3:1 sand and cement mix would be considered impermeable and is not suitable for use with PolySweep.

Once the product has been swept into the joints and compacted with a whacker plate, use a leaf blower or soft brush to remove all excess material from the paving surface before activating with water – any residue left on the surface during watering can cause staining. Mist the surface with water and allow it to absorb for approximately 5 minutes before repeating the process three to four times, gradually increasing the volume of water with each pass. It is important that water penetrates through the full depth of the joint, not just the top layer – check penetration depth with a screwdriver in one of the joints. The final pass should be sufficient to rinse any remaining residue from the surface. Blow off or brush away any surface water sitting in the texture of the paving before leaving to cure.

Cure times depend on temperature and humidity. As a general guide, the paving can accept foot traffic after 24 hours. Full curing typically takes 24-48 hours in good conditions. Do not allow vehicle traffic until the joints are fully cured. Curing will be slower in cooler or more humid conditions, and the area should be protected from rain throughout the curing period.