A1-rated cement sheathing board is introduced by Proctor Group.
A. Proctor Groupintroduces a new fibre cement sheathing board,named A1 Cement Board, to its range of facade solutions. This innovative addition, when used in conjunction with the acclaimed Wraptite® external air barrier, offers a more systematic solution to contractors and specifiers. The A1 Cement Board, having undergone through-wall fire testing, can be employed with Wraptite® to support compliance with fire safety requirements in relevant buildings.
Will Jones, Head of Business Development at A. Proctor Group, explained, "The A1 Cement Board, being a cementitious product, is inherently non-combustible. Our thorough fire performance data generated from these tests guarantees compatibility between the sheathing board and our Wraptite® membrane." This assurance allows customers to make informed decisions when selecting an all-encompassing external air barrier and vapour permeable membrane.
At its developmental core, the A1 Cement Board was created to deliver the best solution overall. By combining the traditional advantages of fibre cement boards with the appealing qualities of newer gypsum sheathing boards, it offers a lightweight alternative that is less cumbersome during on-site handling and cutting. According to Lewis Stanley, Business Development Manager (High Rise & Facades) at A. Proctor Group, "Fibre cement boards are known for their heavy build and challenging site manipulation. However, the A1 Cement Board offers an easier handling solution due to its streamlined design."
Cladding rails and brackets can directly fix onto the A1 Cement Board, eliminating the need for specialized fasteners that penetrate the frame behind. Moreover, thanks to the compatibility with Wraptite®, it removes the need for tapes and sealants on the sheathing board for temporary weather protection and airtightness.
Comprehensive technical support, as well as on-site assistance including all complementary fixings and accessories, backs all products from the A. Proctor Group. To learn more, visit www.proctorgroup.com
Enhanced Fire Safety and Performance
The combined use of A1 Cement Board and Wraptite® presents considerable fire safety benefits for facade solutions. These benefits support the overall safety and performance of building envelopes.
- The A1 Cement Board's non-combustibility makes it an excellent choice for cladding and sheathing in external wall systems, reducing the risk of facade fires.
- Cement boards can maintain their integrity at high temperatures, providing a durable and safe barrier during fire events.
- As a protective substrate, the A1 Cement Board shields the internal timber or structural frame from direct flame exposure, delaying facade fire progression.
The Role of Wraptite® in Fire Safety
- Wraptite® is a self-adhered membrane that creates an effective airtight and moisture-resistant barrier, potentially limiting fire spread through air leakage pathways.
- By wrapping the building’s exterior walls and roof, Wraptite® helps maintain a continuous protective envelope, minimising gaps that might allow fire or smoke infiltration.
- Wraptite®'s resistance to water penetration and dust ingress helps maintain the integrity of fire-protective layers by preventing degradation from moisture or contaminants.
Combined Benefits in Facade Systems
The synergistic relationship between A1 Cement Board and Wraptite® provides a robust, non-combustible, airtight, and weather-resistant facade assembly. The cement board serves as a fire-resistant substrate, while the Wraptite® membrane seals the envelope against air and moisture infiltration that can exacerbate fire conditions. This combination contributes to improved airtightness, reduced thermal bridging, fewer penetrations at junctions and openings, and enhanced protection for building envelopes.
An illustrative example is the Scalby Road project, where the external wall assembly consisted of timber studs with insulation, sheathing board (like A1 Cement Board), rigid insulation, and the Wraptite® membrane followed by cladding or rendering. This layering approach improved both airtightness and fire safety by ensuring the building envelope was well protected against fire, moisture, and air leakage.
In summary, the combination of A1 Cement Board and Wraptite® external air barrier optimizes facade fire safety by delivering a non-combustible, continuous, airtight, and moisture-resistant exterior wall system, thereby effectively limiting fire spread and safeguarding the structural elements of buildings.
- The weather conditions during installation can affect the handling of the A1 Cement Board, so contractors must monitor the forecast before initiating work.
- Technology plays a crucial role in testing the compatibility between the A1 Cement Board and Wraptite® membrane, ensuring they work effectively together in facade solutions, particularly for fire safety.
