Roof refurbishment can have significant consequences for fume cupboard extract systems. Contractors may need to remove fans, external ductwork and supporting components before roofing work can begin. Reinstatement then requires careful planning, accurate records and specialist knowledge.
A university recently appointed The Fume Cupboard Company to assess and reinstate 19 roof-mounted extract fan units and their associated UPVC ductwork. A third-party contractor had removed the equipment to allow a flat roof refurbishment project to proceed.
What initially appeared to be a straightforward reinstatement quickly revealed damaged components, missing location records and several recommissioning risks
Surveying the existing fume cupboard extract systems
Before starting the reinstatement, our engineers carried out a detailed roof-level survey.
The equipment comprised:
- 12 centrifugal extract fan units
- Six small bifurcated fan units
- One large bifurcated fan unit
Following removal, the third-party contractor positioned all 19 fans and sections of associated ductwork at the southern end of the roof.
One of the first challenges involved identifying which fans and ductwork sections belonged to each original extract system. No clear records appeared to link the individual components to their previous roof locations.
Without accurate labels, photographs or marked-up drawings, a specialist contractor must undertake additional work before reinstatement can proceed. This project therefore highlights the importance of carefully recording fume cupboard extract systems before dismantling them during building refurbishment work.
Universities rely on fume cupboards to protect laboratory users from harmful airborne contaminants. Guidance on the safe use of fume cupboards also highlights the importance of correct operation, maintenance and testing.
Ageing Components Within Fume Cupboard Extract Systems
During the survey, our engineers identified significant deterioration in sections of the UPVC ductwork and weather cover plate cravats.
Years of UV exposure and changing weather conditions had taken their toll on the external components. Our inspection identified:
- Sun-bleached ductwork
- Brittle UPVC sections
- Damage caused during removal and handling
- Weathering components that were unsuitable for reliable reuse
Although some components may appear reusable, degraded ductwork and weathering details can compromise the long-term integrity of an extract system.
We therefore recommended replacing the damaged external components instead of attempting to reuse them. This approach formed a key part of our proposed reinstatement solution.
Reinstating Fume Cupboard Extract Systems Following Roof Refurbishment
Once the client approved our recommendations, The Fume Cupboard Company commenced the reinstatement works.
Our team completed the following work:
- Reinstalled all 19 roof-mounted extract fan units
- Connected the roof outlets to the fan inlets with new UPVC ductwork
- Replaced the existing weather cover plate cravats
- Fitted new fan inlet connection assemblies
- Renewed ductwork supports where required
- Laid new felt beneath the paving slabs supporting applicable fan units
- Hot-air welded or glued the ductwork joints, depending on the application
The new fan inlet connection assemblies formed an important part of the reinstatement strategy. These assemblies accommodate operational vibration while maintaining the integrity of the connection between the fan inlets and adjoining ductwork.
Our engineers also replaced degraded connection components identified during the survey. This work restored the external extract path and reduced unnecessary stress on the associated UPVC ductwork.
Independent Testing and Verification of Fume Cupboard Extract Systems
After our team completed the installation work, an independent specialist contractor tested and verified the fume cupboard extract systems.
The Fume Cupboard Company managed the condition survey, repairs and reinstatement. Independent performance testing then provided further assurance that the systems operated as intended following recommissioning.
Successful testing gave the client confidence to return the extract systems to service after the roof refurbishment project.
Industry guidance recognises commissioning and testing as essential elements of good LEV practice. The HSE’s HSG258 guidance covers the design, commissioning, testing and ongoing performance of extraction systems.
Regular examination and testing remain essential throughout the working life of fume cupboard and LEV extraction systems. Learn more about our LEV testing services and how we support system performance, compliance and laboratory safety.
Recommissioning Risks for Fume Cupboard Extract Systems
The condition of the existing fans presented another important consideration.
Older fans may not restart successfully after an extended period of inactivity. Bearings, motors and electrical components can deteriorate while the equipment remains out of service.
For that reason, we advised the client that some fan units might require repair or replacement if they failed to restart during recommissioning. Our original work scope did not include replacement fans, internal fan components or alterations to the discharge stacks.
Early identification of this risk allowed the project team to consider possible contingencies and avoid assuming that every existing fan would restart without difficulty.
Lessons Learned During a Fume Cupboard Extract Systems Reinstatement Project
This university roof refurbishment provided several useful lessons for facilities managers, estates teams and principal contractors:
- Record fan and ductwork locations before removal.
- Label individual components clearly and consistently.
- Photograph the original installation from several positions.
- Inspect external UPVC ductwork before considering reuse.
- Assess weathering details after long-term roof exposure.
- Allow for the possibility that dormant fans may not restart.
- Arrange suitable testing before returning systems to service.
- Involve a specialist extract contractor during the planning stage.
When building or roofing works disrupt fume cupboard extract systems, successful reinstatement involves much more than reconnecting the removed equipment.
Early coordination helps the project team protect critical components, manage interfaces and identify potential problems before they affect the programme.
A Successful Reinstatement Project
Our detailed survey identified damaged components, informed the reinstatement strategy, guided the installation works and supported the successful independent verification of the reinstated extract systems.
Specialist involvement supported the project from the initial roof survey through to completion. Our engineers identified deterioration, addressed the relevant risks and completed the required reinstatement works.
After installation, an independent contractor verified the systems. The client could then return the fume cupboard extract systems to service following completion of the university roof refurbishment.
Planning Roof Works That Could Affect Your Extract Systems?
Roof replacement, plant maintenance and wider building refurbishment can all affect roof-mounted laboratory extraction equipment. Early specialist involvement can help protect existing assets and prevent costly surprises later in the project.
The Fume Cupboard Company provides surveys, refurbishment, reinstatement, installation, testing support and ongoing maintenance for fume cupboard and LEV extraction systems throughout the UK.
Contact our team to discuss how we can protect and reinstate your fume cupboard extract systems during forthcoming roof refurbishment or building works.