In modern construction, air sealing is no longer just about comfort and energy savings – it’s a crucial element in protecting life and property. At Sentinel Contracting Plc we understand that airtightness and fire safety go hand in hand. That’s why our approach to air sealing and testing goes beyond the basics, delivering high-performance solutions that improve energy efficiency, enhance indoor comfort, and most importantly, support fire safety in commercial buildings. 

---

What is Air Sealing? 

Air sealing refers to the process of meticulously closing all gaps, voids, and openings in a building’s structure. This includes areas around windows, doors, pipes, wiring, ductwork, and service penetrations. While often associated with heat retention and reduced energy bills, air sealing also plays a vital role in a building’s fire strategy. 

Without effective air sealing, buildings suffer from uncontrolled air leakage. In fact, up to 50% of all heat loss through a building’s envelope can be attributed to poor airtightness. But even more critically, unsealed gaps serve as pathways for fire, smoke, and toxic gases during an emergency. 

---

Air Sealing for Fire Safety 

When fire safety is considered, air sealing takes on even greater importance. Sealing penetrations, cavities, and openings in walls, floors, and ceilings reduces the risk of fire spreading unchecked throughout a structure. 

At Sentinel, we work to identify and seal all potential leakage points – such as those created during the installation of M&E services – to prevent the rapid propagation of flames and smoke. By compartmentalising the building, air sealing helps contain the fire in its origin zone, buying precious time for occupants to evacuate safely and allowing emergency responders to gain control more quickly. 

This work is aligned with the Building Safety Act and the principle of the Golden Thread, ensuring that all passive fire protection measures – including air sealing – are fully documented, traceable, and compliant. 

While the fire safety advantages are clear, a well-executed air sealing strategy brings a range of other benefits: 

• Energy efficiency – Reduces heating and cooling demand, lowering energy bills. 

• Indoor air quality – Prevents external pollutants and allergens from entering. 

• Moisture control – Minimises the risk of condensation, mould, and material degradation. 

• Thermal comfort – Keeps internal temperatures stable, enhancing occupant comfort year-round. 

---

Essential for Ventilated Buildings 

In commercial spaces where mechanical ventilation is used, airtightness is essential to ensure these systems work efficiently. Without air sealing, conditioned air leaks out, forcing HVAC systems to work harder, increasing energy use and costs. Worse still, compromised building envelopes allow smoke and fire to spread through ventilation shafts and service openings in the event of an emergency. 

By integrating air sealing and testing into our firestopping approach, Sentinel ensures that the performance of ventilation systems is protected, and the building envelope functions as a safe, sustainable barrier. 

---

Compliant and Future-Ready 

All Sentinel works are carried out in strict compliance with Building Regulations Part L2, which sets mandatory requirements for controlling air leakage in UK buildings. These regulations are part of a broader government commitment to drive energy efficiency and cut carbon emissions across the built environment. 

By aligning with these standards – and going beyond them where necessary – we help main contractors deliver buildings that are fit for the future, ready to withstand both environmental challenges and fire risk. 

---

Firestopping in Action: Ropemaker Street 

Sentinel Contracting was appointed to deliver full-scale firestopping solutions at Ropemaker Street – a striking commercial development near Moorgate. 

• We sealed service penetrations and applied firestopping materials to maintain the integrity of fire compartments throughout the building. 

• Our work supported the overall fire strategy by helping to limit the spread of smoke and fire through floors and walls. 

• Careful coordination with other contractors ensured a seamless integration with wider building services and construction timelines. 

Read more on the project here. 

At Sentinel Contracting PLC, we’re proud to deliver air sealing and firestopping solutions that meet the highest standards of safety, sustainability, and compliance. For main contractors, that means confidence in your project’s performance – now and for years to come. 

Ready to talk airtightness and fire safety? Get in touch with the Sentinel team today.