PROJECT: Smoke Shaft Testing & Remediation
CLIENT: Barratt Redrow
AT A GLANCE
A smoke shaft is the common term for ventilation systems in the lobbies of tall buildings. They extract any smoke in the lobby to protect the escape stairs and are required under Standard BS7306.
In situations where natural airflow is insufficient or impracticable an Automatic Opening Ventilator (AOV) fan is mounted at the top of the stairwell to force the movement of smoke to allow it to escape through dampers, grills and vents.
It is imperative that shafts and ducts are sufficiently airtight so that they can transport clean air and extract smoke effectively. This helps to save lives by greatly reducing the risk of smoke inhalation in the case of a fire.
Smoke shaft testing of high-rise buildings is required to ensure that it meets national air permeability standards. However they are a at a high-risk of failure.
OBJECTIVES
The smoke shaft of a newly constructed high-rise residential building failed the air tightness test. As a result, the AOV fan manufacturer was unable to approve the installation of the AOV fan, as the equipment would not function as intended under these conditions.
We were tasked with identifying the leaks and diagnosing the underlying issues. Working alongside the Trace Surveys and Corded abseiling team, we carried out the necessary remedial work to resolve the problem and then retested the shaft to ensure it met the required standards.
SOLUTIONS
To address the issue, we enlisted the Trace Surveys abseiling division, CORDED, to visually inspect the smoke shaft for gaps. As the inner surface of the shaft serves as the primary air seal, they ensured the finish was smooth and that all junctions and joints were fully sealed.
Next, we performed a smoke test to pinpoint any leaks and collaborated with the wider Trace Surveys team to develop and oversee a remedial action plan. This involved sealing gaps and coating the blockwork with a specialised sealing substance.
After completing the remedial work, the smoke shaft was re-tested and successfully met the required standards. A certificate was then issued to the AOV fan installer, allowing the installation of this crucial, life-saving equipment.
Trace Surveys and Corded provided an excellent and thorough service and allowed us to remain on programme
