Why blockwork shafts are no longer fit for purpose
In high-rise construction, service risers and smoke shafts are fundamental to life safety. Yet traditional blockwork has never passed BS EN 1366-8 , the core test for vertical shafts under smoke extract conditions. Without proven fire performance, reliance on blockwork introduces compliance risk from the outset.
The installation process is equally problematic. Blockwork requires curing times, wet trades in confined spaces, and scaffolding. Sequencing is delayed, QA is difficult to maintain, and handover often comes with uncertainty.
A tested and certified alternative
Specshaft was developed to remove these risks. It is tested and certified to BS EN 1366-1 and BS EN 1366-8, covering fire resistance, smoke control and pressure performance. Achieving E120/I120 and A1 non-combustibility (BS EN 13501-1), the system delivers both fire integrity and insulation for two hours, while pressure testing confirms ultra-low leakage.
Unlike blockwork, this means compliance is documented and verifiable — not assumed. Fire engineers and Building Control can review full certification and QA documentation as part of the approval process.
Installation without delay
SpecShaft is pre-cut off-site and installed dry in a single visit. It requires no pattressing, board linings or wet trades. With approved contractors backed by £5m PI insurance, it simplifies inspections and reduces liability for developers and insurers.
On projects such as Victoria Riverside in Manchester, SpecShaft was installed in a fraction of the time blockwork would have required, keeping programmes on track and providing tested shafts that Building Control could sign off with confidence.
The era of blockwork shafts is ending. With no BS EN 1366-8 certification and multiple programme complications, they create more risk than certainty.
Specshaft offers a fully tested, A1-rated alternative that combines compliance, speed and assurance in one system. For specifiers, fire engineers and Building Control, it provides a straightforward answer to one of construction’s most complex safety challenges.
To learn more about how Specshaft delivers tested fire performance and faster installation without compromise, visit the Specshaft page