About Sika Separol Plus

Sika Separol Plus is a mould release agent formulated from a blend of mineral and natural oils. It sits between the formwork face and freshly placed concrete as a thin, low-viscosity film, so that when the mould is struck the hardened element lifts away cleanly instead of tearing, plucking or bonding to the shutter. It is supplied ready to use, which means site teams do not have to dilute, mix or activate anything before application – a practical advantage on busy precast beds and cast-in-situ pours where throughput matters more than laboratory precision. The product is a brownish oily liquid, packed in 230-litre drums, and carries a shelf life of twelve months when the drum is kept sealed, undamaged and protected from frost, direct sunlight and contamination.

For contractors and precast manufacturers, the appeal is consistency across many demoulding cycles. A good release agent is not only about getting the concrete off the mould; it is about protecting the face of the element and preserving the mould itself. Sika Separol Plus is engineered to leave a stable, non-tacky film that does not attract dirt, does not corrode steel shutters, and helps keep the concrete surface free of the stains and blowholes that force costly rubbing-down or cosmetic repair later. On architectural and fair-faced work, where the concrete finish is the finish, that difference between an acceptable face and a rejected panel is exactly what a specifier is buying.

The technical insight

The behaviour of an oil-based release agent comes down to interfacial chemistry at the mould-concrete boundary. When Sika Separol Plus is spread as a thin film and allowed to set, it forms a continuous, stable oily layer that concrete cannot wet or key into. Fresh concrete is strongly alkaline and water-rich; without a barrier it grips absorbent timber and reacts against bare steel, causing surface tearing on strike and progressive fouling of the mould. The mineral and natural oil blend interrupts that contact – it repels the mix water at the face and denies the cement paste a mechanical anchor, so the element releases with low, even resistance rather than in patches. Because the film is thin and applied deliberately rather than pooled, it does not migrate into the concrete cover or leave the retarded, dusty face that flooding a mould with heavy oil produces. The same film is chemically passive toward steel, so it protects rather than pits metal shutters, and it holds up on heated formwork where thinner or more volatile products would break down. The practical outcome – fewer air holes, uniform colour, clean stripping – is a direct consequence of a defect-free, unbroken release film being present everywhere the concrete touches the mould.

Where it is used

• Fair-faced and architectural concrete where the as-struck finish is the final surface
• Precast concrete production with repetitive daily demoulding cycles
• Steel and aluminium panel formwork on bridges, tunnels and infrastructure
• Plywood and timber shutter work on residential and commercial frames
• Heated formwork and accelerated-cure precast systems
• Plastic and GRP moulds for repeated casting
• Columns, beams, slabs and shear walls in cast-in-situ construction
• Boundary and precompound elements where clean stripping speeds turnaround

Key advantages

• Ready to use – no dilution, mixing or activation before application
• Forms a stable, thin, non-tacky film that resists dirt pick-up once dried
• Delivers clean, fast, easy stripping and reduces surface damage on strike
• Improves fair-faced finish with fewer stains and blowholes
• Does not corrode steel formwork, protecting mould investment
• High coverage – up to 60 m2 per litre on metal, keeping unit cost low
• Extends the working life of steel, aluminium, timber and ply shutters
• Applies flexibly by spray, brush, roller or cloth to suit any site setup

Limitations & considerations

• Mineral-oil based, so it is not a water-based or VOC-optimised option for projects with strict emission or low-odour requirements
• Highly absorbent formwork such as new timber may need a second application to seal the face
• Over-application and pooling causes retarded, dusty or discoloured concrete – excess must always be wiped off
• Requires dry, clean moulds free of rust and old concrete residue; it will not compensate for poor mould preparation
• Supplied only in 230-litre drums, which is more than a small or occasional job needs
• Consumption varies with surface texture and porosity, so coverage figures are a guide and site trials are advised

Selection & best practice

Specifications

Industry use cases

How we position Sika Separol Plus

Sika Separol Plus is the mineral-oil release agent in Sika’s Separol range; where a project needs a water-based option, look to Sika’s emulsion-type Separol grades instead. Because it is a concrete-production ancillary rather than a structural product, it typically ships alongside the pour rather than the structure – pair it with Sika’s concrete admixtures and Sikament / Sika ViscoCrete superplasticisers for the mix, and with Sika curing compounds and SikaTop repair mortars for post-strike finishing. Contractors already running Fosroc formwork systems often compare it against Fosroc Reebol, the direct mineral-oil equivalent; we stock and advise on both so the choice can be made on price, availability and site preference rather than on what a single distributor happens to carry.

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