The GENESIS Duplex

Dulux Acratex's Technical Specification

Partnering with the team at Contour3D, the Acratex technical and commercial teams used their in-depth knowledge and experience in masonry protection, masonry coating systems, and cementitious substrates, to create a multi-stage coating system delivering long-term performance and protection for the structure's integrity:

1. Initial Sealing (Concrete Curing Agent): To manage the complex hydration process, a Concrete Curing Agent was spray applied immediately to the outer surface of the concrete as the walls were being extruded. This step was vital to ensure the mixture did not dry out prematurely, thereby aiding the controlled curing process.

2. Primer Application: Following the curing period, the surface was primed with Dulux Acratex Green Render Sealer, applied via spraying. As specialists in masonry coatings, we selected GRS because this water-based sealer is specifically designed for the preparation of "green" masonry surfaces.

It provides multiple benefits:

• It minimises efflorescence and fast-tracks coating schedules by sealing the underlying masonry.

• It creates an evenly porous surface for the application of subsequent coats, ensuring optimal adhesion and finish quality.

3. Topcoat Specification: AcraSkin was chosen as the ultimate protective topcoat, providing the required high-performance characteristics:

• High Film Build: AcraSkin was chosen specifically for its high film build (300 micron dry film thickness – DFT - in two coats).

• Protection and Durability: As a high-performance elastomeric membrane, AcraSkin delivers weatherproofing and is optimised for crack bridging protection, accommodating masonry crack movement of up to 2.7mm at 300 microns DFT (9.3 x Dry Film Thickness).

• Aesthetic Finish: AcraSkin was sprayed both inside and out. This technique enabled the team to achieve the required film build and protection with a uniform finish, ensuring the coating complimented the appearance of the textured extrusion.

Aesthetic and Performance Outcomes

The coating system specified by Dulux Acratex successfully met every requirement for this pioneering project, providing long-term value:

• Aesthetic Preservation: The simple system required no render or texture. Spraying the topcoat complimented the texture of the extrusion, ensuring a uniform finish while preserving the appearance of the textured substrate.

• Performance:The application of Green Render Sealer followed by AcraSkin provides long-term protection against cracking and subsequent moisture ingress, a critical factor for the highly dense 3D-printed concrete.

• Energy Efficiency:The integrity of the total coating system contributed to the structure achieving a high 7.9 star energy rating.