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Sika Sikagard-670 W

Sika Sikagard-670 W is a single-component, water-based, flexible elastomeric acrylic anti-carbonation coating for the protective coating of exposed concrete elements. The product is classified under EN 1504-2 as a coating providing principles 1 (protection against ingress) and 8 (increasing resistivity). Sikagard-670 W is supplied as a ready-to-use liquid in 15 L pails, applied by brush, roller or airless spray in two coats over a primer (Sikagard-552 W Aquaprimer or equivalent). The cured coating provides a low-permeability, high-elasticity barrier that significantly reduces CO2 ingress and thus carbonation propagation into the concrete substrate, while accommodating substrate movement (crack-bridging up to approximately 0.3 mm at +23°C) and offering UV-stable colour retention. TRSC specifies Sikagard-670 W as the system finishing coat over completed concrete repair on facade remediation projects, particularly where the architectural finish requires a Sika-system supply chain alignment with the upstream MonoTop or Sikadur repair specifications, and as a stand-alone protective intervention on structurally-sound concrete elements where surface carbonation is the primary durability concern.

Manufacturer Datasheet
TRSC Specifier Commentary

Sika Sikagard-670 W is TRSC's preferred Sika-system anti-carbonation coating, used in the same job profiles as MasterProtect 1000 (the MBS-system equivalent) but selected where the project's repair-mortar specification is Sika MonoTop-412 NFG, the primer is Sika SikaTop Armatec-110 EpoCem, and the structural strengthening is Sika CarboDur S — the natural alignment of a single-supplier Sika system delivers commercial supply chain advantages and removes cross-system compatibility concerns. The product earns its specification slot for the same engineering reasons as MasterProtect 1000: independent EN 1504-2 certification for the relevant protection principles, documented performance data supporting residual-life calculations, and a long Australian installation track record. The most common pitfalls TRSC encounters in the field are: (1) substrate preparation — Sikagard-670 W requires a sound, clean, dry substrate at the time of priming; substrates that are visibly damp, contaminated with surface laitance or curing compound, or carrying surface efflorescence will not achieve the published bond strength and the coating will delaminate within 12-24 months; (2) primer selection — the coating must be applied over the manufacturer-specified primer (Sikagard-552 W Aquaprimer); contractors substituting a generic acrylic primer compromise the coating's adhesion and the published EN 1504-2 performance; (3) application rate — the coating's anti-carbonation performance is a function of the achieved dry-film thickness; TRSC specifications cite a target dry-film thickness (typically 200-250 microns over two coats) and require the contractor to verify with a dry-film thickness gauge at agreed inspection frequencies. One Sikagard-specific consideration is the colour-retention specification: Sikagard-670 W is available in a wide architectural colour range with documented UV stability, which is the relevant specification for facade finishes that must hold colour over a 10-year recoat cycle. The product was used on the Q1 Tower facade re-coating as part of the post-cyclone facade remediation, providing extended carbonation protection and architectural colour finish in a single coating system.

Frequently Asked Questions

Specification questions about Sika Sikagard-670 W

When does TRSC specify Sikagard-670 W over MasterProtect 1000?
Sikagard-670 W is specified where the project's repair-mortar specification is Sika MonoTop-412 NFG and the alignment of a single-supplier Sika system delivers commercial supply chain advantages. MasterProtect 1000 is specified where the project's repair-mortar specification is BASF MasterEmaco. Both products are technically equivalent for standard anti-carbonation coating applications and either is acceptable; the selection is driven by supply chain alignment.
How long does the protective performance last?
Manufacturer-published service life is approximately 10-15 years before recoating is required, depending on substrate exposure (UV, rainfall, atmospheric pollution). TRSC remediation specifications include a recoating allowance in the asset's ongoing maintenance plan, typically scheduled at 10-year intervals. The recoat at 10 years is significantly less expensive than the original full system because the substrate preparation requirement is reduced.
Is Sikagard-670 W UV-stable?
Yes. The product is formulated for UV stability and is supplied in a wide architectural colour palette with documented colour retention over the service life. This is the relevant specification for facade finishes that must hold colour over a 10-year recoat cycle, particularly on landmark buildings where architectural colour is part of the brand identity. Some lower-cost anti-carbonation coatings on the market are not UV-stable in deeper colours and chalk or fade within 2-5 years.
What primer must be used with Sikagard-670 W?
The coating must be applied over Sikagard-552 W Aquaprimer or equivalent Sika-approved primer. Contractors substituting a generic acrylic primer compromise the coating's adhesion to the substrate and the coating's published EN 1504-2 performance. TRSC specifications name the primer product explicitly and require the contractor to retain product batch records as part of the project QA file.
Related Materials
BASF
BASF MasterProtect 1000
Mapei
Mapei Mapecoat ACT
BASF
BASF MasterProtect HB 200
Relevant Services
Remediation Design
Condition Assessment
Sources & Further Reading