Permissible Variations in Passive Fire Construction

In passive fire construction, there are instances where a tested fire stopping system can be applied to on-site variations through the test standard AS 1530.4 – Section 10.12 Permissible Variations.

This section is commonly used to apply fire stopping test results to separating elements and metal pipe penetrations, within the limitations of the standard.

By using permissible variations, Allproof tested solutions on lightweight wall systems can also be applied to concrete or masonry walls. This means Allproof’s lightweight wall test results can be referenced when selecting systems for concrete and masonry walls, as outlined in Allproof’s technical manuals.
The limitation here is that the lightweight wall thickness must be equal to or greater than the thickness of the concrete or masonry wall for the achieved Fire Resistance Level (FRL) to apply. Importantly, the reverse does not apply (you cannot assume concrete/masonry results apply to lightweight walls).

Example: Expanding Available Solutions
For example, if you require test results for a concrete wall with a minimum thickness of 150 mm, Allproof offers 10 tested solutions covering a range of pipe types and sizes.
Using AS 1530.4 permissible variations, Allproof can also offer their lightweight wall testing with a minimum total wall thickness of 90 mm.
This adds over 130 additional solutions that can be used if the achieved FRL meets the project’s requirements.

With new construction methods, materials, and products continually entering the market, the scope of available passive fire protection solutions is rapidly evolving. Educating the industry on permissible variations allows tested solutions from one scenario to be applied in others, greatly increasing the available design options while meeting compliance requirements.

Key Considerations
It is always recommended to:

• Communicate with the Project Team and Fire Engineer when proposing the use of AS 1530.4 permissible variations.
• Ensure fire-rated zones are appropriately considered before adopting any variation.
• Contact Allproof for further details and advice, as additional solutions may be available through alternate test results or alternative solutions.

Examples of Permissible Variations (AS 1530.4 Section 10.12)
Section 10.12.2 – Separating Elements

• Test results for lightweight partitions may be applied to concrete or masonry walls, provided the concrete/masonry wall thickness is equal to or greater than the total lightweight wall thickness.
• Example: A lightweight wall consisting of 13 mm plasterboard on both sides of a 64 mm steel stud equals a 90 mm total wall thickness. These test results can be applied to a concrete or masonry wall of 90 mm or greater and achieve the same FRL stated in the report.
• Note: The reverse does not apply.

Section 10.12.3 – Metal Pipes

• Test results for steel pipes may be applied to copper and ferrous metal pipes, as detailed in Table 10.12.3.1 of the standard, provided the fire stopping system and separating element are identical to the tested system.

Section 10.12.5 – Plastic Pipes

• Test results for plastic pipes cannot be applied to pipes of different diameters, wall thicknesses, or material types.
• Results for vertical penetrations cannot be assumed for horizontal elements, and vice versa.
• Penetrations that are not perpendicular are acceptable only if the fire stopping system has similar exposure and dimensions to the tested prototype.