Older buildings often hold more than just charm. They hold rules, limits, and a mix of materials that were not built to current fire safety standards. When working in protected or listed sites, we have to think carefully about how passive fire barriers are added without damaging original details. Timber fire treatment is something we have installed across many of these buildings, mostly on exposed surfaces like beams, panelling, or staircase frames.
It keeps surface flames under control and slows the burn rate, which is a good start. But is it enough? Especially in places like London where historic buildings share space with modern uses (offices, schools, or social housing), we need more than just surface treatments. Fire safety in listed buildings is not just about what looks right, but what holds up when heat spreads fast. That is where other systems come in to support the work timber treatments begin.
Where Timber Fire Treatment Fits In
Timber fire treatment helps soak into exposed wood and keeps fire from racing across untreated surfaces. It is a go-to for visible beams, wall cladding, and other wood details in older buildings. You will often see it used in schools and social housing blocks with heritage features, especially when the timber has stayed exposed over the years.
Some higher-rated coatings can give timber resistance up to a certain fire class. They help keep flames from spreading quickly and hold back smoke. That makes a real difference in tight corridors or rooms where people live or work every day. But it is a surface solution, not a full barrier.
• Underneath panelling, timber can stay exposed to fire in hidden voids
• Small gaps that carry wires or pipes do not get addressed by surface treatments
• Timber that is not exposed (or sealed behind modern finishes) may not benefit from these products at all
So while these treatments add one layer of security, they do not protect junctions, voids, or hybrid areas where new materials meet old ones.
Challenges of Fire Safety in Protected and Listed Buildings
Listed buildings tend to come with their own set of questions before any work begins. There are design limits, permission issues, and careful checks to avoid damaging original finishes. In these spaces, hidden gaps and layers are common.
• Old wall systems with timber backing behind plaster
• Voids in ceilings where beams pass through in odd directions
• Underfloor gaps that spread smoke fast across connected floors
In many cases, we cannot just remove materials or break into walls. That means whatever we use has to work with the structure, not against it. That is why it is risky to rely on just one approach. A fire plan needs to look at all surfaces, not just the visible ones. It is about sealing off spaces without changing the feel of the building, which calls for low-impact products that still get the job done.
Cementitious and CLT Coatings: A Stronger Layer of Defence
This is where cementitious coatings prove useful. They bond safely in rough or porous areas and help hold back heat for longer periods, even when it is cold out. These coatings add thickness and stability, which can buy time in the worst conditions without needing deep wall removal.
We often apply cementitious fire coatings where timber fire treatment cannot reach. Perlifoc, for example, sticks well to ceiling voids, backboards, and around stiff junction points between walls and beams. In colder months, especially in December when airflow drops and heating bumps up temperature differences, choosing coatings that do not crack means quicker use of sealed spaces.
CLT buildings come up more during hospital extensions or new school wings. These timber core structures react to heat differently, so the systems need to be matched by design. The right coating balances lightweight structure with long-term protection, covering not just the exposed surfaces but also the joins in timber frames.
Applying cementitious coatings to CLT must be planned by looking at the movements between seasonally shifting materials. In winter, as moisture settles and temperatures swing between day and night, these coatings help to keep all elements protected. Combining cementitious and CLT fire coatings can raise the fire rating for walls and floors while respecting the limits of the original building. This method is both effective in multi-use environments and helpful for restoring peace of mind in areas with daily foot traffic.
Layering Fire Protection the Right Way
We never walk into a listed space and apply the same thing in every room. Each building has its own mix, especially where old meets new. That might be an original stair next to a rebuilt floor, or a new plant room fitted into an old storeroom. Layering is the better approach.
• Start with a proper fire survey to see where upgrades are allowed
• Use timber fire treatment on exposed surfaces that will not be altered
• Where deeper cover is needed, add cementitious coatings in less visible areas
• Apply products like Perlifoc in utility voids, service risers, and beam gaps
The key is to build up fire resistance using more than one system. It allows us to offer protection for varied surfaces and hidden spots which can be entry points for heat and smoke. Cementitious and intumescent coatings can wrap around odd junctions or fill in spaces that old timber treatments alone cannot reach. By organising work in short phases, we lower disruption. In London, there is often pressure to finish upgrades during school holidays, winter breaks, or before main public events begin. Our approach works with these constraints.
During winter, schedules can get tight. We find that shorter, phased installs help limit closure time, especially before Christmas when public buildings try to finish key works during quiet stretches. Fitting this work in while keeping disruption low matters, not just for safety but for long-term building preservation.
Looking After the Old Without Compromising Safety
Timber fire treatment gives heritage buildings an added layer of defence, but by itself, it often does not go far enough. Fire does not stick to visible paths. It finds the hidden routes (through service holes, behind cornices, under floors). That is where newer materials come in, meeting the gaps the older systems leave behind.
Balancing the look and safety of protected spaces means using fire products that respect both the fabric and function of older buildings. Combining timber surface treatments with modern systems like Perlifoc and cementitious coatings lets us plan smarter (keeping people protected and structures intact without overstepping the line on what can and cannot be touched).
At ATOL Construction, we understand that effective fire safety in heritage spaces throughout London requires a thoughtful approach. We combine proven treatments with modern coatings to create the best results for listed properties and public buildings. Discover how a solution like timber fire treatment can become a part of your wider fire protection plan. Share your project details with us and our team will help you put together the optimal mix for your requirements. Reach out to start the conversation.
