“Smoke vents rendered inoperable by building work” alerts CROSS-UK

AOVs are often designed to resemble regular windows for visual reasons. This may lead contractors to overlook their critical function. Even if the windows are recognised as being different from the standard, their important role in the fire safety strategy may not be perceived.

The CROSS-UK Safety Report 1347 ‘Automatic Opening Vents not functional after two cladding remediations’ describes two events where AOVs (styled to look like windows) were rendered inoperable for months after a cladding remediation. In the first case, contractors improperly disconnected the AOVs from their electrical components. In the second case, new cladding was screwed into the frame of the existing AOVs.

CROSS-UK Safety Report 1380 ‘Automatic Opening Vent covered during remediation works’ involved a sub-contractor being engaged to apply render as the final finish of the façade post-remediation. Working on the exterior of the building, from scaffolding, the sub-contractor’s operatives took measures to protect the AOVs from the render that was to be applied.

There may have been no sign or indication that the AOVs were not standard windows. The applied masking would have prevented the vents from opening in the event of a fire.

Fire risk assessment review

Those responsible for fire safety should ensure that the fire risk assessment is reviewed to reflect changes to risk created by building work. During such work, there’s an increased likelihood of fire, particularly so if combustible materials are exposed.

Elements of a building’s fire safety system may not be recognised as critical by other trades or professions. Where such safety systems will be impacted by building work, a thorough review of the fire risk assessment and fire strategy must be undertaken, focusing squarely on the current evacuation strategy.

For instance, a ‘Stay Put’ approach may need to be reviewed. Consideration should be given to interim control measures to mitigate any identified risks. Where mitigation measures remain inadequate to control the risk, consideration should be given as to whether the building remains safe to occupy. This is particularly relevant for buildings with combustible cladding during any removal works.

Contractors should always be aware of the potential for their activity to impact fire safety, both by increasing the likelihood of a fire through the introduction of combustible materials or hot work, and by interfering with the operation of fire safety provisions such as doors, detectors and AOVs. An AOV might easily be rendered inoperable by a scaffold pole, temporary masking, the storage of materials or any adjustments to cladding.

Temporary signage

Where work is being undertaken on an existing building, the principal contractor (in conjunction with the person responsible for the management of the building’s fire safety) should identify all AOVs and consideration should be given to providing temporary signage indicating that they are to be kept operable and clear from obstruction.

Consideration should also be given by industry to providing permanent, but discrete, signage on AOVs. This might read ‘Automatic Opening Vent – Do Not Obstruct’. This need not interfere with the building’s architecture.

Improved training is recommended for all those in the construction industry who work onsite to raise awareness of the existence of AOVs and their fire safety function. In England, the ‘Responsible Person’ under the Fire Safety (England) Regulations 2022 (Regulation 7) is also obligated to report faults in essential firefighting equipment for high-rise residential buildings. This includes those instances when equipment is disabled.