The problem on site
Exposed concrete facades on commercial towers, residential developments, bridges, and infrastructure projects across India frequently show signs of early deterioration. Site engineers and project managers often observe dark staining, uneven discoloration, map cracking, and brown rust streaks bleeding through the exterior surface within just a few years of project completion.
These blemishes compromise the architectural appearance of fair-faced and exposed concrete structures. More importantly, surface discoloration is rarely just an aesthetic issue. In most cases, visual staining indicates that physical and chemical degradation is already underway inside the concrete cover zone. When left unaddressed, this deterioration progresses to surface flaking, delamination, and concrete spalling, creating safety hazards and escalating long-term repair costs.
Why it happens
Concrete is naturally an alkaline material. During hydration, it produces calcium hydroxide, which maintains a high pH environment around embedded steel reinforcement. This alkaline environment forms a microscopic passive oxide film over the steel, protecting it from corrosion.
External elements break down this natural defence over time. Carbon dioxide present in the atmosphere diffuses into the concrete matrix through interconnected capillary pores. When carbon dioxide dissolves in moisture within the concrete pores, it reacts with calcium hydroxide to form calcium carbonate. This chemical reaction is known as carbonation.
Carbonation steadily neutralises the alkalinity of the concrete, driving the pH level downward. As the carbonation front advances deep enough to reach the depth of the reinforcing steel, the protective passive film around the rebar breaks down. In the presence of atmospheric oxygen and moisture, the unpassivated steel begins to corrode. As steel corrodes, its volume expands, generating internal tensile stresses that crack the concrete cover, produce visible rust stains, and eventually break the surface away.
How Space Arc Engineering approaches it
Preventing carbonation requires a systematic approach rather than a simple cosmetic fix. Space Arc Engineering acts as an authorised project distributor and solution provider, supporting contractors, applicators, and site engineers with technical guidance and verified construction chemicals.
Space Arc Engineering does not manufacture chemicals. Instead, our role is to bridge the gap between material manufacturers and job-site execution. We evaluate the project requirements, external exposure levels, and substrate conditions to recommend the correct protective coating system. Surface preparation is critical to success; even the most reliable protective system will fail if applied over laitance, dust, curing compounds, or active moisture.
Our team assists site teams in assessing the soundness of the concrete, identifying honeycombing or blowholes that require cementitious fairing coats, and verifying that the surface is clean, dry, and receptive to protective coatings.
The system we supply
To arrest carbonation and protect exposed structures, Space Arc Engineering supplies Fosroc Dekguard S, an anti-carbonation protective coating for exposed concrete manufactured by Fosroc.
Fosroc Dekguard S is an aliphatic, solvent-based coating system developed specifically for the long-term protection and decoration of external concrete facades. As a protective barrier, the system delivers several critical engineering benefits on site:
- Reduces carbon dioxide ingress: The coating acts as a barrier against atmospheric carbon dioxide, significantly slowing the rate of carbonation and preserving the alkaline passivity around reinforcing steel.
- Allows the substrate to breathe: While resisting liquid water penetration and carbon dioxide diffusion, the coating allows water vapour to escape from within the concrete. This breathability prevents vapour pressure build-up behind the film, which could otherwise cause blistering or peeling.
- Available in a decorative finish: In addition to barrier protection, the coating provides an even, decorative appearance that conceals surface irregularities and enhances the visual quality of exterior facades.
As an authorised distributor, Space Arc Engineering supplies Fosroc Dekguard S directly to project sites along with the manufacturer-specified primers to ensure system compatibility and adhesion.
What to check before you order
Before ordering an anti carbonation coating for concrete facades, site teams should confirm several technical parameters to ensure proper specification and coverage:
Substrate maturity and moisture
Concrete must achieve adequate curing before application. Coating over green concrete or concrete with high residual moisture can trap water, leading to adhesion failure. The surface must be touch-dry before applying solvent-based materials.
Surface defects and repairs
Exposed concrete must be sound and free from honeycombing, tie-rod holes, bug holes, and open cracks. Inspect the substrate thoroughly. Use compatible polymer-modified repair mortars or fairing coats manufactured by Fosroc to level the surface prior to coating.
Contaminants and previous treatments
Shuttering oils, curing membranes, grease, and efflorescence act as bond breakers. The concrete surface should be prepared using appropriate mechanical methods, such as light abrasive blasting or high-pressure water washing, followed by thorough drying.
Environmental conditions during application
Check the ambient temperature, substrate temperature, and relative humidity at the project location. Application must not proceed during rain, fog, or when condensation is likely to form on the concrete facade.
Talk to our technical team
Selecting the right protective system and getting the application sequence correct protects structures from costly future rehabilitation. Space Arc Engineering provides end-to-end supply, project scheduling, and technical guidance for commercial, infrastructure, and industrial facades across the region.
To review specifications, request material estimates, or discuss application parameters for your upcoming project, speak directly with our technical sales team:
Phone: +91 99991 55255 / +91 72900 89007
Website: www.space-arc.in
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