Sika SikaLatex SBR
A styrene-butadiene rubber latex that upgrades ordinary site mortar into a tougher, water-resistant, better-bonding mix for repairs, screeds, renders and tanking.
What is it?
A milky-white SBR (styrene-butadiene rubber) latex emulsion that is added to the gauging water of cement slurries, mortars, screeds and grouts to improve adhesion, flexibility and water resistance.
Where is it used?
Bond coats between old and new concrete, polymer repair mortars, waterproof plaster on roof slabs, sunken slabs, basements, retaining walls and water tanks, plus screeds, renders and tile-bedding mortar.
Why use it?
It lets a contractor make one liquid do five jobs, turning site-batched mortar waterproof and crack-resistant while adding a reliable ~1.5 N/mm2 bond to the substrate.
How is it applied?
Diluted with water and gauged into cement or cement-sand mixes at set ratios, then brush-applied as a slurry bond coat or trowel-applied as modified mortar, followed by moist curing for 3-5 days.
About Sika SikaLatex SBR
SikaLatex SBR is Sika India’s multipurpose styrene-butadiene rubber latex, the kind of workhorse polymer that a site engineer reaches for when plain cement mortar simply is not good enough. It is fully water-soluble and goes straight into the gauging water of a slurry, mortar, concrete or cementitious grout. Once mixed, the latex film that forms around the cement particles is what does the real work: it fills the pore structure, adds flexibility and dramatically improves how the fresh mortar grips onto old concrete, brick or stone. The result is a mix that is more waterproof, tougher and far less prone to shrinkage cracking than an unmodified equivalent.
For contractors across Delhi NCR and pan-India, the appeal is versatility from a single drum. The same product bonds a fresh concrete cast to a cured one, waterproofs a sunken slab or overhead tank, upgrades a repair mortar for spalled columns, and improves a tile-bedding or plaster mix. Space Arc supplies SikaLatex SBR as an authorised Sika distributor and applicator, so you get genuine, in-date material backed by the current Sika India data sheet and on-ground technical support to match the right dilution and dosage to your actual job.
The technical insight
The chemistry is straightforward but effective. SikaLatex SBR is a stable dispersion of styrene-butadiene rubber particles in water. When you gauge it into a cement mix and the concrete begins to hydrate and lose water, those latex particles coalesce into a continuous polymer film that threads through the cement matrix and lines the capillary pores. That film is what physically blocks the water pathways, giving the hardened mortar its waterproofing and low-permeability behaviour, while its inherent elasticity absorbs micro-movement and reduces cracking. At the interface, the same latex wets and keys into the substrate far better than a cement-only slurry, which is why a properly applied bond coat develops a tensile adhesion strength of at least 1.5 N/mm2 with failure occurring in the concrete rather than at the bond line (tested to EN 1542). A useful side effect is that the polymer plasticises the mix, so you can hold workability at a lower water-cement ratio, which itself makes the set mortar denser and more durable.
Where it is used
- Slurry bond coat between old cured concrete and new concrete or mortar in repair work
- Polymer-modified repair mortars for patching spalled or damaged concrete
- Waterproof plaster and coatings for roof slabs, sunken slabs, basements and retaining walls
- Tanking and internal waterproofing of water tanks, sunshades and overhead structures
- Screeds and floor toppings needing improved bond, toughness and reduced dusting
- Renders and masonry mortars where flexibility and water resistance matter
- Tile-fixing and panelling bedding mortar for better adhesion
- Polymer cement injection grout for filling and sealing cracks
Key advantages
- One product covers five site jobs: bonding, waterproofing, repair mortar, screed and grout modification
- Makes site-batched mortar and plaster genuinely waterproof and resistant to salt permeation
- Develops a strong substrate bond (tensile adhesion strength greater than or equal to 1.5 N/mm2, concrete failure per EN 1542)
- Improves toughness and flexibility, reducing shrinkage and thermal cracking
- Bonds well to concrete, stone, brick and other common substrates
- Cuts the water-cement ratio for equal workability, giving a denser, more durable set mortar
- Reduces surface dusting and improves frost and chemical resistance of concrete
- Dilutable with water up to six times, so a single drum stretches across varied applications
Limitations & considerations
- It is a mortar and slurry modifier, not a standalone membrane; it must always be mixed with cement (and sand where specified), never brushed on neat as a bond coat
- Waterproof coatings should be over-screeded or otherwise protected where they are exposed to traffic or long-term ponding
- Over-addition of water thins latex-modified mortar rapidly because of its plasticising effect, so gauging water must be controlled
- Pot life is short, roughly 20-30 minutes at +30 degrees C, so mixes must be batched and used in small, workable quantities
- Application is limited to substrate and ambient temperatures between +5 and +40 degrees C, and freshly applied work must be shielded from direct sun, strong wind and rain
- For deep-crack injection or heavy structural repair it plays a supporting role and is used alongside dedicated products such as Sika MonoTop-108 Water Plug IN or Sikadur-31 IN
Selection & best practice
Prepare the substrate first: it must be sound, clean and free of oil, grease, laitance, loose particles and old coatings, and smooth surfaces should be mechanically roughened to give a key. Pre-saturate cementitious substrates to a saturated-surface-dry condition with clean water at least two hours before application, then remove standing water so the surface reads dark matt without glistening. Gauge SikaLatex SBR into the mixing water at the correct ratio, add the cement or cement-sand blend slowly while stirring, and mix by hand or low-speed drill for no more than about two minutes to a smooth, lump-free consistency; keep stirring during use so cement does not settle out. For bonding, brush the slurry vigorously into the surface and place the fresh mortar or concrete while the bond coat is still wet and tacky. Restrict modified plaster or mortar to about 20 mm per layer, building thickness in lifts at roughly 12-hour intervals. Curing is critical: cover with polythene, wet hessian or a curing compound such as Sika Antisol, cure for a minimum of 3-5 days, and do not pond with water before five days.
Specifications
| Chemical base | Styrene-butadiene rubber (SBR) latex emulsion |
| Appearance / colour | Liquid, milky white |
| Specific gravity | ~1.02 |
| pH value | 8 plus or minus 1 |
| Tensile adhesion strength | Greater than or equal to 1.5 N/mm2 (concrete failure), EN 1542 |
| Dilution with water | Up to 6 times, depending on application |
| Waterproof coating / bond coat mix (by weight) | SikaLatex SBR : Water : Cement = 1 : 4 : 8 |
| Application / substrate temperature | +5 degrees C min. to +40 degrees C max. |
| Pot / application time | ~20 to 30 minutes at +30 degrees C |
| Packaging | 250 g, 500 g, 1 kg, 5 kg, 10 kg, 20 kg and 100 kg containers |
| Shelf life / storage | 18 months from production; store dry, +5 to +35 degrees C, out of frost and sun |
Industry use cases
Building repair & rehabilitation
Contractors use it as a bond coat and repair-mortar additive to reinstate spalled RCC columns, beams and slabs, ensuring the new patch grips the parent concrete rather than debonding later.
Waterproofing (roofs, tanks, basements)
Applied as a waterproof slurry or plaster on sunken slabs, overhead and underground water tanks, retaining walls and basements where a dense, water-resistant cementitious layer is needed.
Residential & commercial finishing
Added to plaster, render and tile-bedding mortar to cut cracking, improve adhesion on smooth surfaces and reduce dampness in wet areas like bathrooms and balconies.
Industrial & warehouse flooring
Modifies screeds and floor toppings to raise bond strength, toughness and abrasion resistance while reducing surface dusting on working floors.
Infrastructure & water-retaining structures
Used in polymer cement grouts and coatings for treating leaching, saltpetre action and cracks in canals, tanks and other water-retaining civil works.
Frequently asked questions
Can I brush SikaLatex SBR directly onto concrete as a bonding agent?
How much do I dilute it, and what is the dosage?
Is SikaLatex SBR a complete waterproofing membrane on its own?
How long does the mixed material stay workable?
What packaging is available and what is the shelf life?
How should I cure mortar made with SikaLatex SBR?
How we position Sika SikaLatex SBR
SikaLatex SBR sits in the middle of Sika’s site-mortar range as the all-round SBR latex. It is routinely used alongside other Sika products that appear in the same workflow: Sika MonoTop-108 Water Plug IN for plugging active leaks and sealing crack lines before grouting, Sikadur-31 IN epoxy adhesive for fixing injection nozzles and structural bonding, Sika Fabric-50 as reinforcing scrim between waterproof coats, and Sika Antisol as the curing compound over finished work. For projects that need a factory-blended, pre-bagged repair mortar rather than a site-modified one, step up to the Sika MonoTop patch-repair family. On the Fosroc side, the genuine equivalent is Nitobond SBR, so specifiers standardised on Fosroc systems have a like-for-like option without changing methodology.
Fosroc Nitobond SBR — Choose Nitobond SBR when the project is already specified on Fosroc systems or the site team wants a like-for-like SBR bonding aid and mortar additive within the Fosroc range.
Related Concrete Repair products
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.