Frequently Asked Questions

When exactly should Sika Antisol S be applied after concrete placing and what happens if application is delayed in hot Indian summer conditions?

Sika Antisol S must be applied immediately after final surface finishing of the concrete — typically within 15 to 30 minutes of bleed water disappearance on the surface in Indian summer conditions (above 35 degrees C, relative humidity below 50 per cent, wind speed above 10 km/h). The evaporation rate calculation method per ACI 305R (plotting temperature, humidity, and wind speed on the evaporation rate nomograph) determines when plastic shrinkage cracking risk is high — when evaporation exceeds 1 kg/m2/hour, Sika Antisol S application is essential and must occur as soon as physically possible after the finisher completes each section. If application is delayed past the point where the surface has dried and is no longer reflective wet, curing compound application will have minimal benefit — the critical window of plastic state moisture retention has passed and hairline plastic shrinkage cracks will already have formed. For large slab pours, divide the slab into strips and have a dedicated sprayer following immediately behind the finishing operation so that no section is left uncured for more than 15 minutes after finishing. On multi-lift pours, apply Sika Antisol S to each completed strip before the next strip pour begins.

Does Sika Antisol S need to be removed before tile or screed installation over the cured concrete slab?

Yes — Sika Antisol S wax membrane must be removed from the concrete surface before any subsequent bonded application such as floor tile adhesive, polymer floor screed, waterproof coating, or concrete repair mortar. The wax membrane is designed specifically to prevent moisture transfer — this same barrier property prevents adhesive, screed mortar, or coating from bonding to the concrete substrate. Removal is achieved by mechanical preparation: grinding (hand or ride-on diamond grinder), scarifying, or grit blasting to remove the wax layer and expose the raw concrete surface below. On internal floor slabs to receive tile or screed after 28-day curing, specify grit-blasting or grinding to Sa 2.5 visual standard before applying any bonded system. For external road pavement concrete receiving no subsequent bonded overlay, Sika Antisol S does not need to be removed — it will degrade naturally through weathering and traffic within 4 to 8 weeks. For precast concrete elements to receive repair mortar or architectural coating, grind or blast before application. Always check the Sika technical datasheet and the requirements of the subsequent bonded product before leaving Sika Antisol S in place.

Can Sika Antisol S be used to cure concrete on vertical surfaces such as column faces and retaining walls after formwork removal?

Sika Antisol S can be applied to vertical concrete faces such as column surfaces, retaining wall faces, abutment walls, and other vertical structures immediately after formwork removal. On vertical surfaces, the concrete surface is typically moist and cool from the protected curing inside the formwork, and curing compound application prevents the surface from drying out rapidly when exposed to hot ambient air and direct solar radiation. Use a hydraulic spray gun with a fan nozzle — not an airless airspray — to apply Sika Antisol S to vertical surfaces in a single, continuous, overlapping wet coat. Ensure the product is applied from top to bottom to prevent the later-applied upper coat from dripping over the earlier-applied lower coat and breaking the membrane. The coverage on vertical surfaces is typically at the lower end (around 4 m2 per litre) because the surface profile of formed concrete is rougher than a power-trowelled slab, requiring more product to achieve a continuous membrane. For columns and piers in exposed, sunny, and windy site conditions in North India during April through June, Sika Antisol S curing after form stripping is strongly recommended, supplemented with wet hessian or shade cloth wrapping for the first 48 to 72 hours if peak temperatures exceed 45 degrees C.