Bostik Cementone SBR 25L is used to modify mortars, screeds and renders to improve mix strength and durability, reduce water penetration and improve salt resistance. Cementone SBR can also be used as a bonding agent for all cementitious system. It is compatible with ordinary Portland Cement, rapid hardening, sulphate resisting and high alumina cements.

Key features

• Bonds in dry and damp conditions
• Provides improved adhesion, mix strength and durability

Preparation
Ensure surfaces are sound, clean, dry and free from grease, oil, paint, laitance and loose materials. Key surfaces by scabbling, grit blasting or planning. If steel reinforcement is exposed on concrete, use a wire brush to remove rust and scale. Prime exposed steel with a bonding slurry and allow drying. Dampen porous surfaces thoroughly with water.

Application
Prepare the bonding coat consisting of 2 parts ordinary Portland Cement slurried with 1 part Cementone SBR by volume and work vigorously into the surface with a stiff brush. Screed or render must be applied while the bonding coat is still wet. Sands used must be well graded, clean and meet the appropriate British Standard. Aggregates must be dust free. Cementone is an admixture for screeds, renders and for fixing brick-slips, coping and tiles. Use at the rate of 5-10 litres Cementone SBR to 25Kg cement. Due to the plasticising action of Cementone SBR care should be taken when adding mixing water to keep workability correct.