About Fosroc Brushbond RediMix

Fosroc Brushbond RediMix is a two-component, acrylic polymer-modified elastomeric waterproofing membrane engineered for concrete and masonry surfaces. It belongs to Fosroc’s well-established Brushbond family of cementitious-acrylic coatings and is supplied as a pre-matched kit: a powder component of specially selected cements, graded hard-wearing aggregates and additives, paired with a liquid component of blended acrylic copolymers. On site the two are combined — with a measured quantity of clean water to reach brush consistency — to produce an easily applied, seamless coating. When cured, the acrylic copolymer network gives the film its defining qualities: strong adhesion to both porous and non-porous substrates, toughness, flexibility and durability. Because it is breathable, the membrane allows water vapour to escape from the interior of the structure rather than trapping it, while still blocking liquid water from outside. The “RediMix” designation reflects its positioning as a convenient, pre-packaged, ready-to-mix version within the Brushbond range, intended to cut down on site measuring errors and simplify application for contractors. It is widely used in India for terrace and roof waterproofing, sunken toilet slabs, bathrooms, basements, water tanks and the rehabilitation of damp or leaking masonry, and it can be over-laid with screeds or tile beds where mechanical protection is required. As an authorised Fosroc distributor and applicator, Space Arc Engineering supplies Brushbond RediMix with technical guidance and, where needed, applicator support across Delhi NCR and Pan-India.

The technical insight

The performance of Brushbond RediMix comes from a polymer-modified cementitious matrix: the cement-aggregate fraction provides body, alkalinity and a chemical bond into the substrate, while the acrylic copolymer emulsion forms a continuous flexible film that knits the cement particles together and imparts elasticity. This combination is what allows the coating to bridge fine, static shrinkage cracks rather than fracturing with the substrate, and to remain bonded as a seamless membrane without joints or laps. Unlike a pure liquid-applied acrylic, the cementitious phase lets the product be applied directly to damp — but not actively running — concrete and masonry, because the cement can hydrate against moisture; this is a major practical advantage in Indian site conditions where achieving a bone-dry substrate is often impractical. The cured film offers good resistance to carbon-dioxide and chloride-ion diffusion, which slows carbonation and chloride-induced corrosion of embedded reinforcement, so the membrane doubles as an anti-carbonation and concrete-protection coating, not merely a barrier to water. Resistance to water under pressure is thickness-dependent: Fosroc states the coating resists positive hydrostatic pressure up to a 7-metre head, with a minimum 2 mm build recommended (protected by a screed) for areas subject to moderate-to-heavy hydrostatic loading. Pot life is limited — about 30 minutes at 27 degrees C — and retempering with water after initial set must be avoided, so mixing should be matched to the rate of consumption. Within the wider Brushbond family the elastomeric grades vary in flexibility (for example, Brushbond Flex offers roughly 40-70% elongation, FLXIII about 127% to ASTM D412, and UltraFlex more than 150%); RediMix sits as a general-purpose elastomeric membrane where moderate crack accommodation, ease of mixing and broad utility are the priorities rather than maximum elongation.

Where it is used

• Waterproofing of concrete roofs, terraces and chajjas, typically over-laid with a protective screed
• Internal wet areas — toilets, bathrooms and sunken slabs — before tiling
• Basement and retaining-wall waterproofing on the positive (water) face
• Water-retaining structures such as tanks and reservoirs (use potable-grade Brushbond variants where contact with drinking water applies)
• Sealing and re-facing leaking brick and masonry walls and evening out surface variations
• Anti-carbonation and protective coating for reinforced-concrete elements exposed to corrosive salts and atmospheric gases
• Damp-proofing of foundations, plinths and retaining structures

Key advantages

• Two-component, ready-to-mix kit reduces on-site batching errors and gives consistent results
• Bonds directly to damp concrete and masonry, minimising surface-drying delays
• Excellent adhesion to both porous and non-porous substrates
• Seamless, jointless elastomeric film that bridges fine static shrinkage cracks
• Breathable — allows water-vapour transmission from inside the structure while blocking liquid water
• Good resistance to carbon-dioxide and chloride-ion diffusion, protecting embedded steel
• Tough, durable coating resistant to wear and damage; can be over-coated with screeds or tile beds
• Minimal surface preparation and low labour cost; simple brush or trowel application
• Non-toxic and suitable for a wide range of building and infrastructure uses

Limitations & considerations

• Short pot life of about 30 minutes at 27 degrees C — mix only what can be used in time, and do not retemper with water
• Cementitious-acrylic film offers moderate crack accommodation; for high movement or dynamic cracks, a higher-elongation grade (Brushbond FLXIII/UltraFlex) or a PU/PMB membrane is more appropriate
• Pressure resistance depends on applied thickness — a minimum 2 mm build plus protective screed is needed for moderate-to-heavy hydrostatic loads
• Not a UV-stable decorative topcoat for permanently exposed traffic surfaces; exposed roofs should be protected by a screed, tiles or a suitable topcoat
• Should not be applied below about 10 degrees C application temperature
• Requires a sound, clean substrate — spalled or disintegrated concrete must first be cut out and repaired (e.g. with the Renderoc system)
• Exact figures (pack-specific coverage, DFT, cure) must be read from the current country datasheet, as values differ across the Brushbond range and by region

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Brushbond RediMix

Brushbond RediMix sits in the broad, general-purpose tier of Fosroc’s waterproofing portfolio: a dependable, easy-to-mix acrylic-cementitious membrane for everyday roof, wet-area and masonry waterproofing where moderate crack accommodation is sufficient. Within the Fosroc range it pairs naturally with Renderoc repair mortars for substrate reinstatement, Nitobond bonding agents, and Nitoseal/Nitoproof products for joints and detailing; where higher flexibility or dynamic crack-bridging is required, step up to Brushbond Flex, FLXIII or UltraFlex, and for heavy-duty tanking or roofs consider Proofex membranes or polyurethane systems. Against competitors, it occupies the same space as Sika’s SikaTop Seal / Sika MonoTop-style polymer-modified cementitious coatings, Dr. Fixit’s Newcoat / LW+ and cementitious crystalline ranges, MBS (MYK LATICRETE / MasterSeal-type) two-component coatings, and STP (Shalimar) acrylic-cementitious membranes. Honestly assessed, RediMix’s edge is convenience, proven Brushbond track record, damp-substrate tolerance and good CO2/chloride resistance; its trade-offs are a short pot life and only moderate elongation compared with premium elastomeric or PU systems. For most Indian residential and commercial positive-side waterproofing, it is a sound, cost-effective specification — and as an authorised Fosroc distributor and applicator, Space Arc Engineering can advise on the right Brushbond grade and supply it across Delhi NCR and Pan-India.

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