What You Need To Know About Fire Door Seals

ALL types of fire doors require appropriate fire door seals to be fitted onto them.

There’s no room for discussion; a fire door leaf that is not fitted with intumescent seals cannot be considered a fire door. The considered design of a fire door seal allows them to expand under extreme heat, thereby sealing off all gaps between the door leaf and frame.

A fire door seal’s role is to prevent the passage of smoke and fire, thus containing the fire to one part of the building and buying precious minutes for those inside.

Fire Door Seals Or Intumescent Seals? What Are They?

Fire door seals are more commonly known as Intumescent Seals or Intumescent Strips within the fire door industry. These seals are fitted onto the head or stiles of a doorset, either within the grooves machined into the top of the door, or attached onto the surface.

Intumescent materials produce a light char, which itself is a very poor conductor of heat. These materials are able to retard heat transfer and are largely fire resistant, making them unlikely to burn.

Most importantly, intumescent seals are designed to swell once exposed to temperatures exceeding 200^oC, which can occur within the first 15-20 minutes of a fire. So long as they are properly installed, fire door seals will fill the gaps around the door leaf and achieve fire compartmentation.

Ammonium phosphate, Hydrated sodium silicate, or Intercalated graphite-based materials are typically used within fire door seals. Typically, the biggest issue with those materials is they can be brittle and conflict with the final aesthetic of your doorset.

Most specifiers, therefore, opt for a non-obtrusive PVC casing (usually referred to as a PVC shroud) to surround the intumescent strip. These shrouds don’t affect the fire-mitigating properties of the fire door seal when activated. These casings are also available in a range of finishes, ranging from RAL colours to a wood-grain effect.

Fire Door Seals & Regulations

To achieve FD 30 or FD 60 certification, fire doorsets must offer sufficient fire resistance, and in the latter case, be smoke sealed. To provide the required level of resistance, ALL fire doors should be fitted with appropriate intumescent strips, along with cold smoke seals.

These intumescent strips are available in a variety of different sizes, allowing them to be used in conjunction with each other to achieve specific fire ratings.

Important: Too many intumescent strips are almost as bad as none. The expanding materials within them mean that there is a risk of pushing the door out of the door frame if the wrong quantity are used. Always allow your fire door manufacturer to correctly assess and specify the correct intumescent materials.

Furthermore, British Standard 476 fire-safety standards state that fire doorsets should be S-type (smoke sealed). Installing a fireproof door with intumescent strips can help the door meet these standards.

Their regulations state seals must limit leakage to an hourly rate of 3 cubic meters of smoke through 1 metre of the door edge.

It’s worth noting that simply adding intumescent seals to a door will not suffice to make a regular door classify as a fire doorset.

How To Specify Intumescent Seals In Fire Door Seals

Unless you have first-hand experience in doorset manufacturing we advise that you do not specify your intumescent strips and instead leave that to the manufacturer.

As doorset specialists and manufacturers, the responsibility of ensuring correct intumescent specifications is down to us, as there are many technical aspects involved.

Every aspect of the doorset, from the size of the door leaf, purpose of the door, proposed ironmongery, and even location can affect intumescent calculations or the intumescent recipe.

Why Are You Specifying A Different Intumescent Component To Last Time?

Perhaps one of the biggest misconceptions among architects, specifiers, and joiners is that it’s a one size fits all world when it comes to fire door seals.

You should ALWAYS speak to your doorset manufacturer about your site-specific criteria, as this will often change the specified doorset and components.

A doorset that fails in the event of a fire will cost lives. By treating every project as an individual and unique case, we can all be assured that the best solution is offered.

Importance Of Proper Fire Door Installation

Fire door installation should always be carried out by a qualified professional. Fire Door NVQs are the most prevalent trusted qualification, as well as the FIRAS and BM Trada Q-Mark Fire Door Schemes.

This ensures that doorsets are installed in strict accordance with the guidelines set out by the fire door manufacturer.

Shockingly, in 2020 FDIS (The Fire Door Inspection Scheme) researched the incorrect installation of fire doors; 76% of fire doors they inspected were condemned and tagged as ‘not fit for purpose’.

The FDIS identified that the most common issues were:

• Excessive gaps around the door leaf
• Smoke sealing-related issues
• Incorrectly adjusted door closers.

Please don’t add to this growing issue. Your fire doorset manufacturer will ensure that the correct intumescent materials are present for your building. It’s the responsibility of the architect, contractor, and construction professionals to ensure correct installation.

Conclusion

The key takeaways here are these: ALWAYS ensure your fire doorsets are fitted with intumescent strips and consider the deadly outcome of incorrect installation.

Such a small component on your fire doors can be the difference between 30-60 minutes before a building is engulfed in flame. Fire door seals are designed to save lives and are just as important as the door leaf and architrave.

To guarantee correct specification and mitigate future risks, you should always use a trusted fire door manufacturer and installer.

The trigon of companies forming RW Joinery will take you through the specification, manufacture, installation, and maintenance processes within one certified and seamless fire doorset scheme.

If you’d like to discuss your project in more detail, why not talk to an expert today? Simply fill out the form below or call us on 0161 480 8722.