Bostik Cementone SBR Primer and Admixture – Bulk Buy – Strengthens and Waterproofs Mortar Mixes

Bostik Cementone SBR extended information

Bostik SBR toughens, waterproofs and improves chemical and abrasion resistance of renders, screeds and mortar. It is an excellent all round primer and bonding agent and is especially suitable for external applications.

It can be used for waterproof rendering, flooring screeds and toppings and for bonding renders & suction control. It is a specially modified Styrene Butadiene Co-polymer Latex for cement and mortar.

Bostik Cementone SBR Product Characteristics

Bostik Cementone SBR Typical Performance Data

PREPARATION

Bostik SBR has been designed to work with Portland cement: CEM I and Portland-fly ash cement: CEM II/B-V. For other types of cement, e.g. Portland-limestone CEM II/A-LL it is recommended that a small trial is carried out to ascertain the optimum mix ratios as cement and sand types can vary.

IMPORTANT: Do not use in concrete which is structural i.e. load bearing, reinforced, pre-stressed or steam cured. Work
should not be carried out at temperatures below +5°C or when temperatures are expected to fall below this. Ensure materials and procedures comply with the appropriate standards. Do not exceed ratios stated. Do not overmix. Do not use with other admixtures. Do not add to lime based mixes. Do not use with high alumina, sulphate resisting or extra rapid hardening cement. When rendering protect render from drying too quickly. This product is not vapour proof, therefore structures must incorporate a suitable damp-proof membrane. Ensure the substrate is strong enough to support the weight of any screeds or render being applied.

1. Ensure that all components of the mix and the working temperature are above +5°C.
2. Sands and aggregate must be dry, well graded, clean and meet the appropriate standards. Aggregates must be dust-free.
3. Ensure surfaces are sound, clean, dry and free from grease, oil, paint, laitance, loose materials and any other surface contaminants.
4. Key surface by scabbling, vacuum grit blasting or planning.
5. For all applications, dampen porous surfaces before applying the appropriate SBR bonding slurry. Ensure the
working temperature is over +5°C.

APPLICATION

6. Shake well before use.

IMPORTANT: Do not overmix or over trowel mixes modified with Bostik SBR.

Bonding slurry: For screeds, toppings, renders and coatings.

7. Mix 2 parts cement to 1 part SBR by volume to a stiff brushable consistency. Do not add water.

8. Apply evenly to dampened surface to a thickness of between 1mm and 2mm.

9. Apply screed, topping, render or coating while the slurry is tacky (this normally takes 20 to 40 minutes).

Please note the following recommendations are for guidance only and do not constitute a specification.

Floor toppings and screeds:
10. Mix and apply the following mix designs dependent on thickness required:

Bostik Cementone SBR for thicknesses <12mm

Bostik Cementone SBR for thicknesses >12mm

* 5 litres of water is recommended for dry sand mixes. If sharp washed sand is wet, reduce water quantity accordingly.

11. Keep mix just wet enough to obtain good compaction. Finish quickly with a steel trowel.

External waterproof renders above ground:
12. Apply bonding slurry, stipple to provide a key and allow to dry.
13. Then apply second bonding slurry coat at right angles to the first, stipple to provide a key.

Bostik Cementone SBR Render coat mix

14. Add up to 5 litres of water for dry sand mixes. Reduce quantity accordingly if sand is wet.

15. Apply first render mix while second slurry coat is still tacky to a minimum thickness of 6mm.

16. After no more than 8 hours, apply a second render coat to a maximum thickness of 6mm.

17. If more than 8 hours has elapsed, apply a bonding slurry between coats.

18. Prevent from drying out during the first 48 hours by covering with polythene or mist spraying with water when initially firm.

OTHER APPLICATIONS

Suction control:
19. Mix 1 part SBR to 4 parts water. Brush on to surface and allow to dry.

CLEANING

20. Clean tools and equipment with water immediately after use. Dried product is difficult to remove.