Four Common Firestopping Mistakes

November 21, 2024

Firestopping is an aspect of building construction that involves sealing openings or gaps in walls, floors, and ceilings to prevent the spread of fire, smoke, and toxic gases. A form of Passive Fire Protection firestopping is highly complex but crucially important, especially as buildings become more sophisticated. Despite this fact, firestopping is often overlooked or improperly installed during construction, leading to potentially catastrophic consequences in the event of a fire. Since most firestopping mistakes are borne from negligence, this paper will highlight ways to avoid these wrong practices so that buildings and its occupants are kept safe and sound

1. Consider the Annular Gap

The annular gap refers to the space between the side of penetration opening and the penetrating material. To prevent spread of water, fire, smoke, and gas, this gap needs to be filled with a tested fire sealant system that allows for expansion, contraction, and movement, and is according to specific test approvals (ETA/BS-EN). Aside from sealants, other types of firestopping materials such as intumescent straps or collars must be installed at the correct depth. If the depth of the material is too shallow, it may not seal the annular gap completely, allowing fire and smoke to still pass through. The best practice is to always follow the instructions of the firestopping system manufacturer carefully.

2. Uncertified Products

Simply put, certified firestopping products provide a higher level of safety and reliability compared to non-certified products. This is because certified firestopping products have been tested and evaluated by independent thirdparty organizations to ensure that they meet specific standards for fire resistance and smoke control. These products have undergone rigorous testing and meet the requirements of building codes and standards. Unlike certified firestopping products which have been tested and approved for their intended use, using uncertified firestopping products can compromise the fire protection system of a building, potentially leading to loss of life, property damage, and legal liability (e.g., cannot claim for fire insurance).

3. Installation Shortcuts

Even the best products, when installed poorly or incorrectly, cannot perform as intended and thereby compromise the integrity of the whole system. The most common shortcuts include using the wrong density of mineral wool, using lesser than the recommended thickness of sealant, using the wrong product in different applications, failing to clean the surfaces to be sealed, not using the proper adhesives, or using a "backer rod" that is too small. All these shortcuts put the building’s structural integrity and its occupants’ safety at risk, not to mention it could lead to code violations and liability issues for building owners, contractors, and installers. Firestopping installation should always be done by trained and certified professionals who underwent the proper product, installation, and technical training by the product manufacturer.

4. Mixing Different Product Brands

Most firestopping products designed by a manufacturer can be used independently or as part of a system because they are compatible when tested together, thereby guaranteeing the most effective passive fire protection while also upholding a valid system warranty. However, if different brands of firestop products are used together, it could compromise the effectiveness of the overall performance of the firestop system because of different properties (e.g., expansion rates or adhesion qualities).


In addition to the risk of decreased fire protection performance, mixing firestopping product brands may not meet building codes and standards, and it can also result in legal and regulatory implications.


More than anything, the best way to avoid any of the above mistakes is to include firestopping early in the building design process. By doing so, it will eliminate so many mistakes during the construction and installation phase, and even provide cost savings if there is no need for remedial work later on.


Blazeout as an independent distributor of Passive Fire and Firestopping products can advise on the solutions required, without having to “push their own brand”. Blazeout can provide impartial advice.

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September 15, 2026
Simplify project procurement with Blazeout. Source firestopping, fire door products, fixings, site essentials and access solutions from one supplier.

Why Seperation Distances Matter in Firestopping

August 24, 2026
When designing firestopping around service penetrations, the distances between individual services and nearby openings is an important part of the overall system design. Pipework, cables, conduits and other penetrations need to be installed within the spacing parameters covered by the relevent tested configuration. Changing those distances can influence how the firestop behaves when exposed to fire. If the specified spacing is not maintained, there may be a greater risk of: - Reduced fire-resistance performance - Earlier-than-expected system failure - Increased smoke passage -Excessive heat transfer to surrounding services or firestopping materials Firestop systems are tested in defined configurations, meaning that the test evidence applies to specific installation arrangements, including the seperation between penetrations. For this reason, seperation requirements should be addressed during the design and coordination stages. Establishing the correct spacing before installation helps ensure the completed penetration matches the configuration for which the firestopping system has been assessed. As the specialist single source distributor of firestopping materials, Blazeout are uniquely positioned to assist with your projects, supplying the correct solutions in full and on time.

Why Does the Door Closer Always get the Blame?

August 24, 2026
When a door fails to close properly, closes too quickly or slams shut, the door closer is often the first component to be blamed. However, while a door closer is designed to provide reliable and controlled closing, its performance depends heavily on the door, frame and surrounding installation working correctly. Door closers play an important role in security, fire safety, noise reduction and preventing damage. But when a door does not swing, close and latch freely on its own, even the best-specified closer may struggle to perform as intended. Before adjusting or replacing the closer, it is worth checking some of the more common causes of poor door operation. Poor Joinery and Installation One of the most common reasons for a door failing to close correctly is poor installation or inaccurate joinery. If the door frame is not plumb, for example, the door may meet the frame at the top but leave a gap at the bottom. A door closer cannot always overcome this type of misalignment. Installation can be particularly challenging in older buildings, where walls and floors may not be perfectly straight. However, similar issues can also occur in new-build properties, so accurate measurement and checking are essential in every installation. Floor levels and threshold gaps also need careful consideration. Variations in floor levels can affect how a door is trimmed and fitted, potentially preventing it from closing freely. At the same time, installers must ensure that any relevant requirements for cold smoke control and threshold gaps are maintained. Even seemingly minor issues, such as an incorrectly fitted or badly trimmed entrance mat, can interfere with the door’s closing action. The key is careful preparation: measure accurately, make the necessary adjustments and always check the door’s operation before considering the door closer. Getting the Door Gaps Right Insufficient clearance between the door and frame is another common cause of closing problems. Where a door is too tightly fitted, it can bind against the frame, creating resistance that prevents it from closing and latching correctly. For fire doors, appropriate gaps are particularly important. The guidance and requirements applicable to the door assembly should always be considered, along with the door manufacturer’s and hardware manufacturer’s instructions. Smoke seals also need to be considered during the installation process. If seals are added without sufficient space or are fitted incorrectly, they can create additional resistance and cause the door to stick before it has fully closed and latched. Using the correct product and following the manufacturer’s recommendations can help avoid these issues. Ironmongery and Other Accessories The door closer is not the only piece of hardware that can affect how a door operates. Locks, latches, keeps and other ironmongery can all contribute to closing problems if they are poorly specified, incorrectly adjusted or badly fitted. For example, some external doors use locks designed to latch automatically when the door is pushed shut. If the locking mechanism is incorrectly adjusted, it may prevent the door from closing or latching as intended. Similarly, a poorly positioned keep plate can obstruct the latch or stop the door from closing fully. When investigating a problem, it is important to consider the entire door assembly rather than focusing on the closer alone. The Effect of Air Pressure Air pressure within a building can also have a significant impact on the performance of a self-closing door. A door and its hardware may be correctly specified and installed, but excessive positive or negative air pressure can prevent the door from closing and latching reliably. In some circumstances, air pressure can also cause doors to swing or close with excessive force. This can be particularly challenging in taller buildings, where changes in pressure and air movement can create unpredictable conditions. Although building design can help minimise the impact of air pressure, it is not always possible to predict every condition. In many cases, a correctly specified door closer can be adjusted to accommodate the environment. Small adjustments can make a significant difference, so changes should be made gradually and the door tested after each adjustment. The Little-Finger Test A simple way to assess whether a door is functioning correctly before blaming the door closer is the “little-finger test”. A well-installed door should be able to swing closed, close fully and latch with very little resistance. If a gentle push from a little finger is enough to close the door, a correctly specified and adjusted door closer should be able to operate it reliably and in a controlled manner. If the door is difficult to close manually, increasing the power of the door closer may not solve the underlying problem. Conclusion Door closers are often blamed when a door fails to close correctly, but the cause is frequently found elsewhere. The frame may be out of alignment, the gaps may be too tight, the threshold may be obstructed, or another item of ironmongery may be preventing the door from closing and latching properly. Before adjusting or replacing a door closer, it is worth checking the fundamentals: the frame, the door gaps, the threshold, the latch and the overall operation of the door itself . A door closer can only perform as well as the door it is fitted to. Get the installation right first, and the closer is far more likely to do exactly what it was designed to do—close the door reliably and with controlled force.