Fosroc Nitobond SBR
Modified SBR latex bonding aid and cementitious mortar additive for durable concrete repair, screeds and renders — supplied and applied by Space Arc Engineering, authorised Fosroc distributor.
What is it?
Fosroc Nitobond SBR is a single-component, ready-to-use modified styrene butadiene rubber (SBR) emulsion — a white liquid polymer that works both as a bonding aid between old and new concrete and as a gauging additive for site-batched cementitious mortars, screeds and renders.
Where is it used?
Used across India in concrete repair, RMC patch repairs, precast yards, screeds, renders and infrastructure rehabilitation — wherever a high-bond, water-resistant, chloride-free cementitious mortar or bonding bridge is required.
Why use it?
It improves adhesion, flexural and tensile performance, and reduces water absorption of cement mortars. Crucially it contains no chloride admixtures, making it safe for reinforced-concrete repair where chloride-induced corrosion is a risk.
How is it applied?
Applied either as a bonding slurry (1 volume SBR : 1 volume water : 3 volumes fresh cement) brushed onto the prepared substrate, or batched into a 3:1 sand:cement mortar at 10 litres SBR per 50 kg cement. New mortar is placed wet-on-wet onto the slurry coat.
About Fosroc Nitobond SBR
Fosroc Nitobond SBR is a modified styrene butadiene rubber (SBR) emulsion supplied as a single-component, ready-to-use white liquid. It performs two roles on a construction site: as a high-strength bonding aid that creates a durable bond bridge between existing concrete and freshly applied cementitious material, and as a polymer additive (gauging liquid) that is mixed into site-batched mortars, screeds, renders and slurries to upgrade their mechanical and durability properties.
Unlike a superplasticiser or water-reducer, Nitobond SBR is not a workability admixture and contains no polycarboxylate ether (PCE) or sulphonated naphthalene (SNF) chemistry. Instead, the SBR polymer films within the cement matrix on curing, improving adhesion to the substrate, raising flexural and tensile strength, increasing resistance to water and chloride-ion ingress, and reducing the risk of shrinkage cracking and debonding in thin sections and feather edges.
A defining technical and specification advantage is that Nitobond SBR contains no chloride admixtures. For reinforced-concrete repair — bridge soffits, columns, beams, water-retaining structures and marine or coastal works — this matters because chlorides accelerate corrosion of embedded steel. Specifiers and structural consultants working to IS 456 durability requirements routinely call for chloride-free repair systems, and Nitobond SBR meets that intent.
For Indian conditions — RMC patch repairs, precast manufacturing, infrastructure rehabilitation and hot-weather site work — its versatility and long-established performance record make it a default choice. Space Arc Engineering supplies and applies Nitobond SBR as an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India. Where a project specification permits equivalents, comparable SBR bonding latexes include MYK Laticrete Latapoxy/Latex ranges, BASF (Master Builders) bonding aids and Sika Latex; however we lead with the genuine Fosroc product for warranty-backed, specification-compliant supply.
The technical insight
When Nitobond SBR is batched into a standard 3:1 sand:cement mortar at the recommended 10 litres per 50 kg cement (approximately 20% by weight of cement), the SBR-modified mortar develops the following 28-day, air-cured properties to BS 6319: compressive strength of 62 MPa, tensile strength of 3.3 MPa, flexural strength of 9 MPa, and a slant shear bond strength of 53 MPa. The high slant-shear value is the key indicator of monolithic bond between the repair mortar and the parent concrete — it is the bond, not just the mortar’s own strength, that governs the durability of a patch repair. The polymer film also lowers permeability, which is what improves resistance to carbonation and chloride ingress in the cured section.
Where it is used
- Bonding bridge between old hardened concrete and new concrete, screed or repair mortar
- Polymer-modified repair mortars for spalled or honeycombed RCC (beams, columns, soffits)
- Floor and bedding screeds requiring improved adhesion and reduced water absorption
- Internal and external renders and plasters on difficult or smooth substrates
- Patch repairs in RMC and precast concrete units
- Waterproofing slurry coats and tanking-mortar additives for water-retaining structures
- Infrastructure rehabilitation — bridges, flyovers, drains and marine/coastal structures
- Feather-edge and thin-section repairs where standard mortar would debond
Key advantages
- Contains no chloride admixtures — safe for reinforced-concrete and water-retaining repair
- Acts as both a bonding aid and a mortar/screed/render additive, reducing the number of products on site
- Improves adhesion, flexural strength (9 MPa) and tensile strength (3.3 MPa) to BS 6319
- Strong slant shear bond of 53 MPa for monolithic, durable repairs
- Reduces water absorption and improves resistance to chloride and water ingress
- Single-component, ready-to-use white liquid — no separate hardener or activator
- Suited to Indian hot-weather repair, RMC, precast and infrastructure work
- Backed by genuine Fosroc supply and applicator support from Space Arc Engineering
Limitations & considerations
- Not a superplasticiser or water-reducer — it will not by itself improve flow or reduce mix water like a PCE/SNF admixture
- Performance values quoted are for a specific 3:1 sand:cement mortar at the recommended dosage; other mixes will differ
- Bonding-slurry coat must be applied wet-on-wet — new material must be placed before the slurry dries, which needs care in hot weather
- Requires correct substrate preparation (clean, sound, saturated-surface-dry) to achieve quoted bond strengths
- Must be protected from frost in storage; shelf life is 12 months in original unopened packaging
- Cured polymer-modified mortar is not a structural substitute for engineered concrete in heavily loaded elements without design checks
Selection & best practice
Prepare the substrate to a clean, sound, mechanically roughened and saturated-surface-dry condition. For the bonding coat, mix 1 volume Nitobond SBR : 1 volume clean water : 3 volumes fresh cement to a brushable slurry and scrub it well into the prepared surface (coverage approximately 2 to 3 m² per litre). Place the repair mortar — a 3:1 sand:cement mortar gauged with Nitobond SBR at 10 litres per 50 kg cement (4 litres per 20 kg cement) — wet-on-wet while the bonding slurry is still tacky; never allow the slurry to dry before applying the mortar. In hot weather, work in small areas, protect from rapid drying, and cure the completed repair properly. Store between use in original unopened drums (20 L or 200 L), protect from frost, and use within the 12-month shelf life.
Specifications
| Chemical base / type | Modified styrene butadiene rubber (SBR) emulsion (single component) |
| Appearance | Ready-to-use white liquid |
| Chloride content | Contains no chloride admixtures |
| Dosage (mortar additive) | 10 litres per 50 kg cement (4 litres per 20 kg cement), in a 3:1 sand:cement mortar |
| Bonding slurry / primer ratio | 1 volume Nitobond SBR : 1 volume clean water : 3 volumes fresh cement |
| Test standard | BS 6319 (28 days, air cured) |
| Compressive strength | 62 MPa |
| Tensile strength | 3.3 MPa |
| Flexural strength | 9 MPa |
| Slant shear bond strength | 53 MPa |
| Coverage as slurry primer | Approximately 2 to 3 m² per litre |
| Supply / packaging | 20 litre and 200 litre drums |
| Shelf life | 12 months in original unopened packaging; protect from frost |
Industry use cases
Infrastructure rehabilitation
Bonding coat and chloride-free repair mortar for bridge soffits, columns and flyover beams where corrosion protection of reinforcement is critical.
Ready-mix & precast concrete
Patch repair of honeycombed or damaged precast units and RMC pours, restoring a durable, well-bonded surface before finishing.
Water-retaining structures
Additive for tanking and waterproofing slurry mortars on tanks, sumps and STPs, where the no-chloride formulation suits reinforced concrete.
Building renovation & screeds
Improves adhesion and reduces water absorption of floor screeds, renders and plasters on smooth or difficult substrates in hot Indian conditions.
Frequently asked questions
Is Fosroc Nitobond SBR a plasticiser or water-reducer?
What is the correct bonding-slurry ratio?
How much Nitobond SBR do I add to a mortar?
Does Nitobond SBR contain chlorides?
What strength can I expect from an SBR-modified mortar?
What packaging and shelf life does it have?
How we position Fosroc Nitobond SBR
Space Arc Engineering positions Fosroc Nitobond SBR as the specification-grade, chloride-free SBR bonding aid and mortar additive of choice for concrete repair and rehabilitation across Delhi NCR and Pan-India. As an authorised Fosroc distributor and applicator, we supply genuine, warranty-backed material with technical and on-site application support. Where a specification permits, comparable SBR latexes from MYK Laticrete, BASF (Master Builders) and Sika exist, but we lead with the authentic Fosroc product to guarantee compliance and documented BS 6319 performance.
Related Concrete Repair products
Source Fosroc Nitobond SBR for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.