The short answer is no. Service penetration test evidence obtained from a standard symmetrical plasterboard wall system cannot be transferred to an asymmetrical shaftwall.
Before we explain why, it is best to first understand what a shaftwall is and the challenges that arise with such systems.
What is a shaftwall?
As the name suggests, shaftwalls are typically used for shafts and risers. A shaft is an enclosed vertical or inclined space spanning multiple storeys, and a riser is a vertical pathway that carries services like water, electricity, data cables, or ventilation between floors. Simply, the shaft ‘houses’ the riser.
Where areas are confined and access is restricted, a shaftwall system is a good option, as it can be constructed from one side only, removing the need for scaffolding or other forms of access equipment. 
The current issue with shaftwalls
Although shaftwalls can be fire tested to the wall test standard, penetrations through these walls, such as fire doors, dampers, and service penetrations, have their own fire-resistant test standards that offer little guidance for shaftwalls.
This means there is very little service penetration sealing evidence in the industry. And because shaftwall solutions are installed from one side only, the fire-resistance performance of the penetration seals can be detrimentally affected by this.
Why standard flexible wall evidence cannot be used
BS EN 1366-3, the test standard for service penetrations, currently does not specify a field of application for shaftwalls.
The interchangeability section of this standard only covers standard symmetrical walls; therefore, without further assessment, this evidence cannot be used for asymmetrical shaftwalls.
Does this mean shaftwalls with service penetrations cannot be tested?
No, shaftwallls with penetrations can be tested. There is a common misunderstanding that only the wall types listed in Section 7.2.2 or in Table 2 of BS EN 1366-3 can be used. However, this is incorrect, as demonstrated in Section 7.2.1:
The supporting construction may be either one of the standard supporting constructions listed in 7.2.2 or a specific construction. In the latter case, however the field of direct application is restricted.
So, a ‘specific construction’, such as a shaft wall, can be tested, but the overall field of application and the use of the test evidence are restricted.
This will depend on the accredited body's decision when the evidence is formally classified or during a field application technical assessment.
How can Quelfire help?
As part of our commitment to fire testing real-life scenarios found on site, we have done extensive shaft wall testing, offering a range of solutions for service penetrations:
- Through 85mm or thicker shaftwalls (access to one side only)
- Through 107mm or thicker shaftwalls (access to one side only)
- Where both sides of the wall are accessible (to install our products as normal)
These solutions can be found in our QuelSelector Firestopping Solution Finder Tool.
A final note
Because of shaftwalls' limitations, engaging early is essential to ensure that all penetrations have a compliant, tested solution.
Quelfire’s technical team is always glad to join early talks with the project’s design teams to help with this. For any further information, please don’t hesitate to contact us.
