Fosroc Dekguard S Standard
High-performance aliphatic acrylic anti-carbonation and chloride-barrier coating for reinforced concrete and masonry, applied as the primer-plus-two-coat Dekguard S Standard system.
What is it?
A single-component, pigmented aliphatic acrylic protective and decorative coating for concrete and masonry, applied as a complete system: a penetrating silane-siloxane primer (Dekguard Primer) followed by two coats of Dekguard S to a total dry film thickness of not less than 150 microns.
Where is it used?
Atmospherically exposed, non-trafficked reinforced concrete and masonry, especially in aggressive marine and coastal environments, on both new structures and as the final protective layer over Renderoc concrete repairs.
Why use it?
It forms a breathable barrier that blocks carbon dioxide, chloride ions, sulphates, oxygen and water while letting trapped water vapour escape, slowing carbonation and chloride-induced reinforcement corrosion, and its highly UV-resistant aliphatic acrylic resists long-term weathering and dirt pick-up.
How is it applied?
Prepare and grit-blast a clean, dry substrate; flood-coat Dekguard Primer at 0.4 litre/m2; once dry, brush, roller or airless-spray two coats of Dekguard S at 0.167 litre/m2 per coat (175 microns wet film each), observing the overcoating times for the ambient temperature.
About Fosroc Dekguard S Standard
Fosroc Dekguard S Standard is the complete, specification-grade protective coating system built around Dekguard S, a high-performance pigmented aliphatic acrylic coating engineered to defend reinforced concrete and masonry from the principal causes of premature deterioration in Indian conditions: carbonation and chloride attack. Carbonation is the slow ingress of atmospheric carbon dioxide that neutralises the alkalinity of concrete cover and removes the natural passive protection around embedded steel, while chlorides from coastal air, de-icing salts or contaminated aggregates attack the steel directly. Both lead to rebar corrosion, expansive rust, cracking and spalling. The Dekguard S Standard system addresses these mechanisms by combining a reactive, penetrating silane-siloxane primer with two coats of the pigmented topcoat, producing a tough, breathable, weather-resistant skin over the structure. The “Standard” designation refers to the standard two-coat build to a minimum 150-micron dry film thickness, as distinct from heavier or fibre-reinforced Dekguard variants. The primer, Dekguard Primer, is a clear liquid based on a silane-siloxane dissolved in a penetrating organic carrier; it reacts within the surface pores to form a chemically bound hydrophobic barrier that inhibits the passage of water and water-borne contaminants. The topcoat is a solvent-based aliphatic acrylic that delivers the bulk of the gas and ion barrier performance plus the decorative finish, available in white and a range of colours made to order. Because the resin is aliphatic rather than aromatic, it does not chalk or yellow rapidly under ultraviolet light, giving exceptional resistance to long-term weathering and excellent dirt pick-up resistance, both valuable on facades and infrastructure that must stay presentable for years. For consultants and asset owners, the system’s value is that it is a single, documented, BS EN 1504-2 compliant solution for surface protection of concrete (principles 1.3, 2.2 and 8.2), making it straightforward to write into a tender specification and to verify on site through film-thickness and coverage checks. As an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, Space Arc Engineering supplies the matched primer and topcoat together with the ancillary Renderoc repair and fairing products that complete a durable, warrantable concrete-protection scheme.
The technical insight
The performance that matters for durability design is the coating’s resistance to carbon dioxide diffusion. Tested to AS/NZS 4548.5-1999, the Dekguard S system at minimum film thickness gives a carbon dioxide diffusion resistance greater than 200 metres equivalent thickness of air (R), equivalent to more than 940 mm of 30 MPa concrete cover, far exceeding the Klopfer criterion of at least 50 metres needed to protect concrete from carbonation. On the Fosroc UK BS EN 1504-2 datasheet the carbon dioxide permeability measured to EN 1062-6 is reported as an Sd of 149 metres against the EN requirement of greater than 50 metres; the higher AS/NZS figure reflects the different test method, so specifiers should cite the value against the standard they are designing to. Critically, this gas barrier is one-directional in effect: the same film is highly permeable to water vapour (water vapour permeability of around 0.75 metres Sd, EN ISO 7783-2, a Class 1 result), so moisture already inside the concrete can dry out rather than being trapped behind the coating, avoiding blistering and osmotic failure. On the chloride side, the system reduces chloride ion penetration by more than 99 percent (Aston University diffusion cell method), with a chloride ion diffusion coefficient of 1.0 x 10⁻¹⁴ m²/sec at 147 days. Volume solids are about 43 to 44.5 percent, the bond strength by pull-off exceeds 1.0 MPa (a measured 2.7 MPa to EN 1542), and the coating achieves a Class 1 spread of flame to BS 476 Part 7 and a Class 0 Building Regulations rating, plus Euroclass B (s1, d0) to EN 13501-1. These are the numbers a corrosion-durability assessment or service-life model should reference.
Where it is used
- Anti-carbonation protection of facades, columns, beams and soffits on RCC buildings and structures
- Final protective and decorative topcoat over Renderoc patch repairs and reprofiling mortars in concrete reinstatement schemes
- Protection of bridges, flyovers, viaducts and other infrastructure exposed to traffic-borne CO2 and pollution
- Chloride-barrier coating for marine and coastal structures such as jetties, sea-front buildings and port facilities
- Surface protection of water-retaining and industrial structures exposed to acid gases, sulphates and aggressive atmospheres
- Decorative, UV-stable recoating of weathered concrete and masonry facades requiring durable colour retention
Key advantages
- Excellent barrier to carbon dioxide, chloride ions, sulphates, oxygen and water, with CO2 diffusion resistance greater than 200m equivalent air thickness
- Breathable film (Class 1 water vapour transmission) lets trapped moisture escape, preventing blistering behind the coating
- Highly UV-resistant aliphatic acrylic resin gives exceptional long-term weathering and colour retention with minimal yellowing or chalking
- Reduces chloride ion penetration by more than 99 percent, directly protecting embedded reinforcement
- Single-component primer and topcoat, both ready for immediate site use with brush, roller or airless spray
- BS EN 1504-2 compliant (principles 1.3, 2.2, 8.2) with Class 0 / Euroclass B fire performance for easy specification
- Excellent dirt pick-up resistance keeps facades cleaner for longer in polluted urban environments
- Integrates with the Fosroc Renderoc repair system for a single-source, warrantable concrete-protection package
Limitations & considerations
- Not designed or suitable for trafficked surfaces such as decks, floors or pavements
- Solvent based and flammable (Dekguard S flash point 42 degrees C, primer 38 degrees C); requires ventilation and ignition-source control during application
- Application must not commence if the substrate temperature is below 2 degrees C or within 3 degrees C of the dew point
- Performance and fire rating may be impaired when applied over existing coatings or paints; trial panels are needed to confirm compatibility, and it must not be applied over elastomeric coatings
- Requires correct substrate preparation (grit-blasting, biocide treatment of algae, filling of blowholes with Renderoc FC) to achieve an unbroken film
- Being a batch-manufactured pigmented coating, slight shade variation can occur between batches, so a single batch should be used for each elevation
- It is a coating, not a crack-bridging membrane, so live or structural cracks must be addressed separately before application
Selection & best practice
Specify and verify by film build, not by appearance. Insist on the full system, Dekguard Primer flood-coated at 0.4 litre/m2 followed by two coats of Dekguard S at 0.167 litre/m2 (175 microns wet) per coat, to reach the minimum 150-micron total dry film thickness on which all the published CO2 and chloride performance depends. Prepare the substrate properly by grit-blasting to remove laitance, curing compounds and contamination, treat any algal growth with a biocide after blasting, and fill blowholes and pitting with Renderoc FC fairing coat (allowing roughly 48 hours cure) so the topcoat forms a continuous, unbroken film. Allow the primer to dry fully before overcoating, and respect the temperature-dependent overcoating intervals (for example 6 hours between Dekguard S coats at 20 degrees C, longer when cooler). Use material from a single batch per elevation to avoid visible shade differences, check wet-film thickness with a comb gauge during application, and confirm dry-film thickness afterwards. Where the coating is applied over a sound existing paint, run trial panels first and prime with a 2:1 Dekguard S to Fosroc Solvent thinned coat as directed, since Dekguard Primer is intended for bare concrete.
Specifications
| Product type / chemistry | Single-component pigmented aliphatic acrylic, solvent-based protective and decorative coating |
| System composition | Dekguard Primer (penetrating silane-siloxane) + two coats Dekguard S topcoat |
| Total dry film thickness (DFT) | Not less than 150 microns |
| Wet film thickness per coat | 175 microns (Dekguard S) |
| Number of coats | Primer: flood coat; Dekguard S: 2 coats |
| Coverage (Dekguard S) | 6 m2/litre per coat (0.167 litre/m2 per coat); approx 3.0 m2/litre total over 2 coats |
| Coverage (Dekguard Primer) | 2.5 m2/litre (0.4 litre/m2) |
| Volume solids | 43% (India TDS) / 44.5% (UK TDS) |
| CO2 diffusion resistance | >200 m equivalent air thickness, R (AS/NZS 4548.5-1999); Sd 149 m to EN 1062-6, requirement >50 m |
| Equivalent 30 MPa concrete cover | >940 mm |
| Water vapour permeability | Class 1, Sd approx 0.75 m (EN ISO 7783-2); requirement <5 m |
| Chloride ion penetration reduction | >99% (Aston University diffusion cell method) |
| Chloride ion diffusion coefficient | 1.0 x 10-14 m2/sec at 147 days (AS/NZS 4548.5-1999) |
| Bond / pull-off strength | >1.0 MPa required; 2.7 MPa measured (EN 1542) |
| Fire performance | Class 1 spread of flame (BS 476 Pt 7); Class 0 Building Regs; Euroclass B s1 d0 (EN 13501-1) |
| Standards compliance | BS EN 1504-2 (principles 1.3, 2.2, 8.2) |
| Overcoating time (Dekguard S, 20 C) | 6 hours (5 hours at 30 C, 12 hours at 2 C) |
| Minimum application temperature | 2 degrees C substrate, and at least 3 C above dew point |
| Colours | White; magnolia, sandstone, portland and wide range of colours to special order |
| Pack size | Dekguard S in 10 or 20 litre drums; Dekguard Primer / Nitoprime DG in 20 litre drums |
| Flash point | Dekguard S 42 C; Dekguard Primer 38 C |
| Shelf life | 12 to 18 months in original unopened packs, cool dry storage |
Industry use cases
Bridges & infrastructure
Anti-carbonation protection of bridge piers, beams, soffits and flyover columns exposed to vehicle-borne CO2 and urban pollution, extending service life by slowing rebar corrosion.
Coastal & marine structures
Chloride-barrier coating for sea-front buildings, jetties and port structures where airborne salt drives reinforcement corrosion; the system cuts chloride penetration by more than 99 percent.
Commercial & residential facades
Durable, UV-stable decorative coating for high-rise and institutional RCC facades, retaining colour and resisting dirt pick-up in dusty, polluted Indian cities.
Concrete repair & rehabilitation
Specified as the final protective layer over Renderoc patch repairs in structural rehabilitation, giving a single-source Fosroc repair-and-protect system.
Industrial & water-retaining structures
Surface protection for industrial buildings, cooling towers and water-retaining structures exposed to acid gases, sulphates and aggressive atmospheres.
Frequently asked questions
What exactly is Fosroc Dekguard S Standard and what does the system include?
How does it protect concrete against carbonation and chloride attack?
What is the coverage and how many coats are needed?
Which standards does Dekguard S comply with?
Can it be applied over an existing painted or coated surface?
Is Dekguard S Standard suitable for floors, decks or trafficked areas?
How we position Fosroc Dekguard S Standard
Within the Fosroc range, Dekguard S Standard sits in the anti-carbonation and protective-coating family alongside Dekguard S Elastic (a crack-bridging, elastomeric grade for substrates with fine movement or hairline cracking) and the water-based Dekguard AC variants. It is most often specified as the protective topcoat that completes a Fosroc Renderoc concrete-repair scheme, with Renderoc FC used as a fairing coat to fill blowholes, Dekguard Primer or Nitoprime DG as the primer, and Nitoprime/Renderoc products for reinstatement, so the natural cross-sell on a Space Arc project is the full repair-and-protect package rather than the coating alone. Compared with the broader market, Dekguard S Standard competes directly with Sika’s anti-carbonation coatings such as Sikagard-550 W Elastic and Sikagard-680 S, with MBS (MYK) and Dr. Fixit anti-carbonation coatings widely used on Indian residential and commercial facades, and with STP and other domestic protective-coating ranges. The honest positioning is that Dekguard S is a solvent-based, highly UV-stable aliphatic acrylic with strong, well-documented CO2 and chloride barrier data and BS EN 1504-2 compliance, making it a sound specification choice for marine, infrastructure and rehabilitation work; where a project demands crack-bridging over an actively cracking substrate, a low-VOC water-based product for occupied-space or environmental reasons, or simply the most cost-sensitive facade option, an elastomeric Dekguard grade or a competing water-based system from Sika, Dr. Fixit or MBS may be the better fit. Space Arc, as an authorised Fosroc distributor and applicator in Delhi NCR and Pan-India, can advise on the right grade and supply the matched primer, topcoat and repair mortars for a coherent, warrantable system.
Related Protective Coatings products
Source Fosroc Dekguard S Standard for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.