About STP ShaliSBR Latex

STP ShaliSBR Latex is a milky-white styrene-butadiene rubber emulsion built to raise the performance of everyday cementitious mixes. Because it is fully water-soluble, it goes straight into the gauging water of a slurry, mortar, concrete or grout rather than being painted on as a separate film. That single change turns a plain sand-cement mix into a polymer-modified system with markedly better adhesion, flexural strength and resistance to water and aggressive salts. The same drum can be dialled in for four distinct jobs — a bonding coat, a waterproofing slurry, a repair mortar or a polymer concrete/screed — simply by changing the mix ratio, which is why site teams keep it on hand as an all-round workhorse.

For a distributor-and-applicator audience in Delhi NCR and across India, the appeal is practical. Mortars gauged with ShaliSBR Latex can be worked horizontally, vertically and overhead, so column jackets, beam soffits and vertical tank walls are all fair game. Applied as a two-part cement slurry it forms a waterproofing membrane on terraces, sunken slabs, basements and water tanks; applied as a bond coat it bridges new concrete to old so repairs do not delaminate. It is supplied in 5 kg, 20 kg and 200 kg drums with a 12-month shelf life, letting a contractor buy a trial pack for a bathroom or a bulk drum for a full basement raft without switching products.

The technical insight

The mechanism is polymer-cement co-curing. As the cement hydrates, the SBR particles dispersed through the mix coalesce into a continuous elastomeric film that laces through and around the cement gel. This polymer network does two things at once: it plugs the capillary pore structure that normally lets water, chlorides and sulphates migrate into concrete, and it adds tensile and flexural capacity that brittle cement lacks on its own. STP’s own data shows the benefit clearly — compressive strength at 28 days rises from a control of 21 MPa to 23.4 MPa, while pull-off adhesion reaches 1.5-2.1 MPa with failure occurring in the concrete rather than at the bond line, the signature of a bond stronger than the substrate. Because the latex is carboxylated SBR rather than a re-emulsifiable powder, the cured film resists hydrolysis and stays intact in damp, externally-exposed conditions, which is why the same product serves both interior repair and exposed waterproofing. It complies with ASTM C 1059-86, Type II (dispersion resin, non-redispersible), the class specified for permanent bonding of latex to concrete.

Where it is used

• Cementitious waterproofing slurries for terraces, sunken slabs, basements, water tanks, lift pits and retaining walls
• Bonding slurry / primer to bridge fresh concrete, screed or plaster to hardened concrete
• Polymer-modified repair mortars for spalled columns, beams, soffits and other RCC members
• Polymer concrete and screed overlays and toppings for worn or damaged floors
• Bedding slurry for tiles and marble over concrete and screed
• External rendering and plaster where crack resistance and water tightness matter
• Protective coat on reinforcement steel to slow corrosion in repair pockets
• General reconstruction, latex-modified overlays and sloping RCC roof waterproofing

Key advantages

• Develops a bond stronger than the parent concrete — pull-off tests fail in the substrate at 1.5-2.1 MPa, not at the interface
• Cuts permeability and resists chloride-ion diffusion plus sulphate and CO2 attack, protecting embedded steel
• Raises flexural strength so repair mortars and overlays crack less under load and thermal movement
• One product covers four jobs — bond coat, waterproofing slurry, repair mortar and polymer concrete — by simply changing the ratio
• Works horizontally, vertically and overhead, suiting soffit and vertical-face repairs
• Improves wear resistance of screeds under rubber-wheeled traffic
• Applies easily by stiff brush with standard site tools and no primer
• Compatible with OPC/PPC cement and available in 5, 20 and 200 kg packs for jobs of any size

Limitations & considerations

• It is a bonding and modifying admixture, not a standalone membrane — waterproofing needs a minimum of two coats, and three in areas of severe water penetration
• Cured performance depends on correct site mixing; guessing ratios or over-watering weakens the polymer-cement film
• Waterproofing coats must be protected by a cement screed overlay at least 25 mm thick before service
• Not for application in direct sun or strong wind, which flash-off the film before it can co-cure
• Cracks must be pre-treated (for example with PlastiSeal) before slurry application — the latex will not bridge structurally moving cracks on its own
• Requires a 24-72 hour moist cure and protection from rain while fresh, so it is sensitive to weather scheduling on site

Selection & best practice

Specifications

Industry use cases

How we position STP ShaliSBR Latex

Within STP’s own range, pair ShaliSBR Latex with PlastiSeal for pre-treating cracks before you apply a waterproofing slurry, and consider STP’s crystalline or membrane systems where a standalone waterproofing layer is specified rather than a polymer-modified coat. As an authorised multi-brand distributor, Space Arc also carries direct counterparts from Fosroc, Sika and Dr. Fixit — useful when a project specification names a particular brand or when a consultant has standardised on one manufacturer for the whole site. If the requirement is purely a repair-mortar or micro-concrete system rather than a bonding latex, we can cross-refer to those product families too.

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