STP ShaliKote AC WB
A water-based, high-build elastomeric coating that keeps carbon dioxide and chlorides out of concrete while letting the structure breathe.
What is it?
An STP water-based acrylic elastomeric coating that forms a micro-porous, high-build film over concrete and masonry to resist carbonation and chloride attack.
Where is it used?
Exposed RCC facades, bridge decks and soffits, storage-tank exteriors, precast panels and coastal structures across Delhi NCR and pan-India projects.
Why use it?
It blocks the CO2 and chloride ions that trigger reinforcement corrosion, yet stays vapour-permeable so trapped moisture can escape rather than blister the film.
How is it applied?
Brush, roller or airless spray in two coats at 3-30 degrees C, priming absorbent surfaces with a 10% water-diluted first coat.
About STP ShaliKote AC WB
ShaliKote AC WB is STP Limited’s water-based, high-build elastomeric protective coating for concrete and masonry. It sits in the anti-carbonation family, meaning its main job is not decoration but defence: it forms a continuous acrylic film that slows the two chemical processes most responsible for premature corrosion of embedded steel, namely atmospheric carbonation and the ingress of air-borne and water-borne chloride. Because the binder is a flexible acrylic polymer rather than a rigid one, the film moves with the substrate and bridges the fine surface cracking that ordinary paints simply telegraph and then split over.
For engineers and consultants specifying durability coatings in Indian conditions, the appeal is practical. The product is single-pack and water-thinnable, so there is no mixing ratio to get wrong and no solvent smell on occupied sites. It carries a non-toxic, low-odour green profile that suits schools, hospitals and residential towers, and it can be finished smooth or textured for facade aesthetics. Space Arc Engineering supplies and applies ShaliKote AC WB as an authorised STP distributor across Delhi NCR and pan-India, pairing it with the right primer and surface treatment for each substrate.
The technical insight
Reinforced concrete stays protected only while the steel sits in a highly alkaline pore environment. Two things destroy that alkalinity: carbon dioxide from the air, which reacts with the concrete to lower its pH (carbonation), and chloride ions from marine or industrial exposure, which break down the passive layer directly. Both need to physically move through the concrete cover to reach the rebar. ShaliKote AC WB works by extending that diffusion path. Its high-build elastomeric film presents a long, tortuous barrier that carbon dioxide and chloride ions struggle to cross, effectively adding decades of equivalent concrete cover in a thin coat. The clever part is the micro-porous structure: the film is dense enough to stop liquid water and gas-phase CO2, yet open enough to let water vapour already inside the concrete diffuse outward. That one-way logic prevents the blistering and delamination that kill non-breathable coatings on damp Indian substrates, while the acrylic elasticity keeps the barrier intact as the facade expands, contracts and develops hairline cracks over its service life.
Where it is used
- Protective coating on exposed RCC building facades and external walls
- Bridge abutments, decks and soffits in carbonation-prone environments
- External concrete surfaces of water and effluent storage tanks
- Precast and in-situ concrete elements needing long-term weather protection
- UV-resistant protective finish on concrete cladding and exposed pipes
- Multi-storeyed buildings, villas and township structures
- Coastal and high-humidity structures exposed to air-borne chlorides
- Subways, retaining walls and other buried-adjacent concrete faces
Key advantages
- Blocks carbon dioxide diffusion, slowing the carbonation that corrodes rebar
- Strong barrier to air-borne and water-borne chloride ions in coastal and industrial zones
- Elastomeric acrylic film bridges fine surface cracks instead of splitting over them
- Micro-porous and breathable, so trapped water vapour escapes and the film resists blistering
- Single-pack, water-thinnable system with no mixing ratios and low on-site wastage
- Low odour, low VOC and non-toxic, suitable for occupied and sensitive sites
- UV-resistant and weather-durable for long facade service life
- Available smooth or textured, giving durability and a decorative finish in one product
Limitations & considerations
- A protective and anti-carbonation coating, not a structural or ponding-water waterproofing membrane
- Crack-bridging suits hairline and fine movement cracks, not active or wide structural cracks
- Performance depends on sound, clean, laitance-free substrate preparation and correct priming
- Water-based film should not be applied in rain, on damp-to-touch surfaces, or below 3 degrees C
- Coverage of 6-7 sq.m/L/coat is theoretical and drops on rough, porous or textured concrete
- Not intended for continuous immersion, negative-side water pressure, or heavy chemical-tank linings
Selection & best practice
Start with a sound substrate: remove laitance, dust, curing compounds, loose material and any old flaking paint, then make good honeycombing and cracks with an appropriate STP repair mortar. Ensure the surface is clean and free of standing water before coating. On old, absorbent or weathered concrete, prime by diluting ShaliKote AC WB with about 10% clean water by volume and applying a first sealing coat; on dense, non-porous surfaces apply undiluted. Then apply in at least two full coats by brush, roller or airless spray, keeping ambient and surface temperature between 3 and 30 degrees C and allowing the manufacturer’s recommended recoat interval between coats. Stir each pail well before use to redisperse any settlement, work to a uniform build without over-thinning, and avoid application when rain is expected before the film has dried. Space Arc’s applicators tune the primer and coat count to the exposure class of each project.
Specifications
| Product type | Water-based elastomeric anti-carbonation protective coating |
| Base chemistry | Acrylic polymer, micro-porous high-build film |
| Theoretical coverage | 6-7 sq.m per litre per coat (surface-dependent) |
| Density | Approx. 1.35 g/cc |
| Application temperature | 3 degrees C to 30 degrees C |
| Application method | Brush, roller or airless spray |
| Priming | Dilute 10% with clean water on absorbent/weathered surfaces; apply undiluted on non-porous |
| Key resistances | Carbon dioxide (carbonation), air-borne and water-borne chloride, UV and weathering |
| Pack sizes | 10 litre and 20 litre |
Industry use cases
Infrastructure and bridges
Protects decks, soffits and abutments from carbonation and de-icing/marine chlorides, extending the maintenance cycle of exposed RCC spans.
Commercial and residential facades
Coats multi-storeyed buildings and villas with a breathable, crack-bridging film that keeps facades weather-tight and presentable for years.
Coastal and marine structures
Shields seafront buildings and jet30-adjacent concrete from air-borne chloride attack in high-humidity coastal air.
Water and industrial storage
Guards the external concrete of storage tanks and industrial plants against aggressive, corrosive atmospheres.
Precast and cladding
Gives precast panels and concrete cladding a durable UV-resistant protective coat that can be finished smooth or textured.
Frequently asked questions
Is ShaliKote AC WB a waterproofing coating?
How much coating do I need per square metre?
Does it need a primer?
Can it be applied over existing painted surfaces?
What kind of cracks can it bridge?
Is it safe for occupied buildings and what pack sizes come in?
How we position STP ShaliKote AC WB
ShaliKote AC WB is the go-to STP choice when the goal is protecting exposed concrete from carbonation and chloride while keeping a decorative, breathable facade finish. Within the STP ShaliKote family it pairs naturally with STP repair mortars for making good spalled or honeycombed concrete before coating, and with STP ShaliKote SWP or SWP WB silicone water-repellents where a penetrating, invisible hydrophobic treatment is wanted instead of a pigmented film. For terraces, tanks and wet areas that need true waterproofing rather than surface protection, point buyers to STP’s dedicated waterproofing membranes. Across our other brands, Dr. Fixit and Sika offer comparable acrylic protective and anti-carbonation coatings for clients standardised on those systems.
Fosroc Dekguard Elastic — Specify the Fosroc option when the project calls for a documented crack-bridging elastomeric coating with BS EN 1504-2 conformity and higher stated crack accommodation for structures with a real risk of ongoing movement.
Related Protective Coatings products
Source STP ShaliKote AC WB for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.