What Can Fix That Gap Or Damage To Your Fire Door?
Fire doors are one of the many ways to use passive techniques to slow the spread of fire in a building. Fire doors must be installed so that no gaps remain between the walls and the door. So, if you have a fire door that has just that little space remaining after the installation, what do you do?
Fire Door Explained
Before getting into the ways to seal those final, small gaps after installing a fire door, it is worth understanding what constitutes a fire door. Fire doors are, just as you would expect, doors, but with a special purpose: slow the spread of a fire within a building by forming a barrier to the fire's spread when closed, but allowing exit from a room or building so you to escape a fire.
For commercial properties, regulations govern the type of door used, installation procedures, heat toleration, and various other requirements. The two most common types of doors are FD30 and FD60 rated doors, meaning that they are rated to withstand 30 and 60 minutes of fire, respectively.
The Fire Door Seal
In order to be able to withstand a fire for 30, 60, or some other number of minutes, a fire door has to provide a complete seal between the room with the fire and the room being protected. To open and close, the door must have gaps so the door isn't constantly sticking in the frame. This is achieved by having seals that will expand under heat. The seals are designed to expand to fill the gaps between the door and the frame after 392 degrees Fahrenheit (200 degrees Celsius). These seals can only expand so far, so the gaps between the top and sides of the door can't exceed 0.16 inches and 0.31 inches for the bottom. Anything more, and fire, heat, and smoke could pass through.
So, that brings you back to the question of what to do if you finish installing the door and there is still a gap. This is where a fire door gap filler can come in handy. A fire door gap filler solution is designed to do just that—fill any gaps that would allow smoke, fire, or heat to come through. Fillers come in three different varieties (at a high level):
- Cut-to-size - these can lay flat, or provide "sweeps" at the bottom of a door to fill that gap between the door jamb and door.
- Hole or damage fillers - these come in the form of caulk or putty-type fillers that restore a door's fire rating
- Foam sealant - these are great to fill non-uniform gaps; the spray foam expands to fill the gap and then dries to form the fire barrier
The key is to pick the fire door gap filler that is best for the job while complying with required regulations.