Fosroc Concure WB Clear
Water-based, low-viscosity wax-emulsion curing compound that forms a clear moisture-retaining membrane on freshly placed concrete, conforming to ASTM C309.
What is it?
A spray-applied, water-based concrete curing compound built on a low-viscosity wax emulsion. It is supplied as a white liquid that dries to a continuous clear film, sealing in mix water so cement hydration completes without external ponding, hessian or sand.
Where is it used?
Large horizontal pours and surfaces where water curing is impractical — RMC pavements, airport runways, bridge decks, industrial floor slabs, canal linings, plus vertical and sloping faces of columns, beams, chimneys and towers.
Why use it?
It guarantees uniform curing across big areas, cuts the labour and water normally tied up in ponding or wet hessian, and reduces plastic and drying shrinkage cracking, surface dusting and permeability — all critical in hot, water-scarce Indian site conditions.
How is it applied?
Apply by low-pressure spray as a single even coat over the full surface as soon as the bleed-water sheen has gone (slabs) or immediately after formwork removal (vertical work), at the rated coverage to form the membrane.
About Fosroc Concure WB Clear
Fosroc Concure WB Clear is a water-based curing membrane used to lock moisture into freshly placed concrete during the critical first days of hydration. It is formulated from a low-viscosity wax emulsion and is dispatched as a white liquid; once sprayed, the water carrier evaporates and the wax coalesces into a thin, continuous, clear film that blankets the surface and dramatically slows evaporation of the mix water. Because the cement is allowed to hydrate with its own water rather than losing it to the atmosphere, the concrete develops its design strength, abrasion resistance and surface durability far more reliably than concrete that is left to dry out.
The “WB” designation marks it as the water-based member of the Concure family, distinguishing it from solvent-based or resin-based curing compounds. This matters on Indian sites for three reasons: it is non-flammable, it carries far lower odour and VOC than solvent grades, and it can be applied in enclosed or partially ventilated areas such as basement rafts, water-retaining structures and tunnels without the fire-and-fumes precautions a solvent membrane demands. The “Clear” variant dries transparent, leaving the natural concrete finish visible — preferred where the slab will receive a subsequent topping, screed, tile bed or decorative treatment and a white pigmented residue would be undesirable.
In practice, Concure WB Clear replaces the traditional curing methods that dominate Indian construction — water ponding, wet hessian, gunny bags and sand layers. Those methods are labour-intensive, consume large volumes of potable water, are almost impossible to maintain uniformly on ramps, runways and tall vertical elements, and frequently fail in the 40-plus degree heat of North Indian summers when water evaporates faster than it can be replenished. A single spray coat of Concure WB Clear forms the moisture barrier for the whole curing period, freeing crews and conserving water while delivering more consistent, crack-resistant concrete. Space Arc Engineering supplies the product as an authorised Fosroc distributor across Delhi NCR and Pan-India.
The technical insight
The product works on the principle of evaporation reduction rather than water addition. ASTM C309 — the standard it conforms to — classifies liquid membrane-forming curing compounds and sets a maximum permissible water loss when the membrane is tested to ASTM C156; Concure WB restricts water loss to a low level (in the order of 0.55 kg/m² over 72 hours under the C156 test), keeping the concrete pore network near-saturated so the hydration reaction is not starved. The wax-emulsion chemistry is the key trade-off lever: the wax film is an excellent vapour barrier and is economical, but it is a curing aid, not a permanent coating or a bonding primer. The fugitive (temporary) nature of the film means it weathers and abrades away over weeks under traffic and UV, which is desirable when a bonded overlay must follow — but where a topping, screed, paint or membrane is to be bonded soon after, the residual wax film must be mechanically removed (grit-blasting, grinding or scabbling) to avoid a bond-breaker layer. This single characteristic governs almost every correct-use decision on site.
Where it is used
- Curing of ready-mixed concrete pavements, roads and hardstandings
- Airport runways, taxiways and aprons where uniform large-area curing is essential
- Bridge decks, flyover slabs and approach slabs
- Industrial and warehouse floor slabs prior to bonded toppings being prepared
- Canal linings, reservoir floors and water-retaining structure walls
- Vertical and sloping faces — columns, beams, retaining walls, chimneys and cooling towers
- Precast yards curing large panels and elements
- Mass-concrete raft foundations and basement slabs
Key advantages
- Single spray application forms the moisture barrier for the entire curing period
- Eliminates water ponding, wet hessian, gunny bags and sand — major labour and water savings
- Water-based and non-flammable, with low odour and low VOC for enclosed-area use
- Dries to a clear film, preserving the natural concrete appearance for subsequent finishes
- Reduces plastic and drying shrinkage cracking, surface dusting and permeability
- Conforms to the internationally recognised ASTM C309 curing-compound standard
- Reaches and coats vertical, sloping and irregular surfaces that are impossible to pond
- Fast-drying, allowing the surface to be brought into service sooner than wet-cure methods
Limitations & considerations
- The dried wax film acts as a bond-breaker — must be fully removed before bonded toppings, screeds, tiles, paints or membranes are applied
- It is a curing aid only, not a sealer, hardener or protective/decorative coating
- Performance depends on uniform spray coverage at the correct rate; thin or missed areas cure poorly
- Not intended for application below the minimum surface/ambient temperature stated on the TDS
- Less suited where a permanent surface finish or dustproofing is required (a cure-and-seal or hardener is then preferable)
- Heavy rain shortly after application, before the film forms, can wash off the membrane
- Shelf life is limited (about 9 months) and the emulsion can be damaged by freezing or excessive heat in storage
Selection & best practice
On flatwork, spray a single uniform coat at the rated coverage immediately after the surface bleed-water sheen has disappeared but while the concrete is still damp — too early and you trap bleed water, too late and evaporation has already begun. On vertical elements, apply as soon as formwork is struck. Use a clean low-pressure sprayer and overlap passes to avoid pinholes or holidays; agitate the drum before use as wax emulsions can settle. Verify the actual coverage by dividing litres used by area covered against the datasheet rate rather than eyeballing it. Crucially, plan the downstream finish first: if any bonded overlay, screed, tile bed, coating or waterproofing membrane is to follow, schedule mechanical removal of the wax film (grinding, shot-blasting or scabbling) and a bond test before that work — never bond directly onto a cured Concure WB surface. Protect freshly sprayed surfaces from rain until the film is touch-dry, and store drums out of direct sun and away from frost.
Specifications
| Product type | Water-based concrete curing compound (clear film) |
| Chemical basis | Low-viscosity wax emulsion |
| Appearance (supplied) | White emulsion / liquid |
| Appearance (dried film) | Continuous clear film |
| Standard conformance | ASTM C309 (membrane-forming curing compound) |
| Water loss (per ASTM C156) | Approx. 0.55 kg/m² (72 h test) |
| Typical coverage | 3.5–5.0 m²/litre (approx. 0.20–0.285 litre/m²) |
| Application method | Low-pressure spray, single uniform coat |
| Packaging | 5 litre, 20 litre and 200 litre drums |
| Shelf life | Approx. 9 months in unopened containers, stored cool and dry |
| Flammability | Non-flammable (water-based) |
Industry use cases
Highways & Airports
Curing of long pavement stretches, runways and taxiways where ponding is impossible and uniform large-area curing controls shrinkage cracking in hot weather.
Bridges & Infrastructure
Bridge decks, approach slabs and flyover surfaces cured in a single pass, reducing crew time on exposed, traffic-sensitive structures.
Industrial Flooring
Curing large RMC floor slabs in warehouses and factories before the wax film is mechanically stripped ahead of a bonded floor topping or hardener.
Water-Retaining Structures
Canal linings, reservoir floors and tank walls cured efficiently — the water-based, non-flammable formulation suits enclosed and damp environments.
High-Rise & Vertical Concrete
Columns, shear walls, beams and tower faces cured immediately after de-shuttering, where wet-hessian curing is unreliable at height.
Precast Manufacturing
Curing of large precast panels and segments in the casting yard for consistent strength gain and reduced surface dusting.
Frequently asked questions
Does Fosroc Concure WB Clear need to be removed before applying a floor topping or tiles?
How is Concure WB Clear different from the white (pigmented) Concure WB grade?
What coverage rate should I plan for?
Is it suitable for water-retaining and enclosed structures?
When exactly should it be sprayed onto a fresh slab?
Can Space Arc Engineering supply Concure WB Clear across India?
How we position Fosroc Concure WB Clear
Within the Fosroc range, Concure WB Clear is the water-based, clear-drying curing membrane — the practical default for general slab and structural curing where a natural finish is wanted and a bonded finish may follow later. It sits alongside Concure WB White (pigmented, more reflective and easier to see for coverage control, better in intense sun) and the solvent/resin-based Concure grades that offer tougher films but bring flammability and VOC. Where a permanent dustproof, sealed or hardened surface is the real goal, a cure-and-seal or a surface hardener such as Fosroc Nitoflor is the better fit rather than a fugitive wax membrane. Against competitor curing compounds — Sika Antisol / Sika curing compounds, MYK Arment, Dr. Fixit Pidicure, BASF/Master Builders Solutions MasterKure, and STP curing membranes — Concure WB Clear competes on ASTM C309 conformance, proven wax-emulsion performance and Fosroc’s distribution and technical support in India; selection between them usually comes down to required water-retention class, finish colour, and whether a bonded overlay or a permanent seal is needed downstream.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.