Mapei · coatings cathodic protection

Mapei Mapecoat ACT

Mapei Mapecoat ACT is a single-component, water-based, anti-carbonation acrylic coating for the protective coating of exposed concrete substrates. The product is classified under EN 1504-2 as a coating providing principles 1 (protection against ingress) and 8 (increasing resistivity). Mapecoat ACT is supplied as a ready-to-use liquid in 14 L pails, applied by brush, roller or airless spray in two coats over a primer (Mapei Malech or equivalent). The cured coating provides a low-permeability barrier that significantly reduces CO2 ingress and carbonation propagation, with documented anti-carbonation performance per EN 1062-6 testing. Mapecoat ACT is supplied in a range of architectural colours and the cured film provides a flat-matt finish appropriate for heritage and architectural facade applications where a softer visual character is preferred over the gloss finishes of some alternative anti-carbonation coatings. TRSC specifies Mapecoat ACT on facade remediation projects where the upstream Mapei repair-mortar specification (Mapegrout T60) and the architectural finish brief favour a flat-matt anti-carbonation coating, and on heritage facade projects where the visual character of the coating is part of the conservation specification.

Manufacturer Datasheet
TRSC Specifier Commentary

Mapei Mapecoat ACT is TRSC's preferred Mapei-system anti-carbonation coating, used on the same job profiles as Sikagard-670 W and MasterProtect 1000 but selected on three grounds specific to the Mapei-system specification: (1) supply chain alignment — where the upstream repair-mortar specification is Mapegrout T60, the natural alignment of a single-supplier Mapei system delivers commercial supply chain advantages; (2) flat-matt finish — Mapecoat ACT cures to a flat-matt finish appropriate for heritage and architectural facade applications where a softer visual character is preferred over the slight sheen of some alternative anti-carbonation coatings; (3) heritage applications — the Mapei system has extensive Italian and European heritage application track record, providing additional regulatory and conservation comfort to heritage approval authorities. The most common specification pitfalls TRSC encounters in the field are: (1) substrate preparation — Mapecoat ACT 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 (Mapei Malech); contractors substituting a generic acrylic primer compromise the coating's adhesion to the substrate 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 180-220 microns over two coats for Mapecoat ACT) and require the contractor to verify with a dry-film thickness gauge at agreed inspection frequencies. One Mapei-specific consideration is that the Mapecoat ACT system is typically paired with Mapefer 1K reinforcement primer rather than Sika SikaTop Armatec-110 EpoCem, maintaining the single-supplier system through the full repair specification. TRSC heritage facade specifications that nominate Mapecoat ACT include the colour designation, the dry-film thickness target, the primer specification, and a witness hold point at the end of the first application phase to verify dry-film thickness compliance.

Frequently Asked Questions

Specification questions about Mapei Mapecoat ACT

When does TRSC specify Mapecoat ACT over Sikagard-670 W or MasterProtect 1000?
Mapecoat ACT is specified on three grounds: (1) where the upstream repair-mortar specification is Mapegrout T60 and a single-supplier Mapei system is preferred, (2) where the architectural finish brief calls for a flat-matt finish appropriate for heritage or architectural facade applications, and (3) where the Mapei system's extensive Italian and European heritage application track record provides additional regulatory and conservation comfort. All three products are technically equivalent for standard anti-carbonation coating applications and any is acceptable; the selection is driven by the project context.
Why does TRSC specify a flat-matt finish on heritage facades?
Heritage facades typically have aged, weathered surfaces with subtle variation in tone and texture that contributes to the character of the building. A glossy or semi-gloss coating produces a uniform sheen that flattens the visual character and can read as inappropriate or "modern" against a historic facade. The flat-matt finish of Mapecoat ACT preserves the subtle variation and reads as more compatible with the heritage character. The selection is part of the conservation specification and is typically agreed with the heritage approval authority.
Is Mapecoat ACT compatible with the Mapei reinforcement primer Mapefer 1K?
Yes. The Mapecoat ACT system is typically paired with Mapefer 1K reinforcement primer rather than the Sika SikaTop Armatec-110 EpoCem alternative, maintaining the single-supplier Mapei system through the full repair specification. Mapefer 1K is the Mapei reinforcement corrosion-protection primer with EN 1504-7 approval; the system pairing simplifies materials submittals and removes cross-system compatibility concerns.
Can Mapecoat ACT be tinted to a specific architectural colour?
Yes. Mapecoat ACT is supplied in a base colour with tinting options through the Mapei ColorMap system, which provides a wide architectural colour palette. For heritage applications requiring a custom colour match (typical of conservation projects where the new finish must match historic paint or render colour), the Mapei technical service can prepare custom-tinted batches; a colour match sample should be approved by the heritage approval authority and the conservation architect before bulk material is supplied.
Related Materials
Sika
Sika Sikagard-670 W
BASF
BASF MasterProtect 1000
Mapei
Mapei Mapegrout T60
Relevant Services
Remediation Design
Heritage Structural Engineering
Condition Assessment
Sources & Further Reading