A fire door is designed to do one critical job: close tightly and seamlessly into its frame to prevent the spread of fire and lethal smoke.
If your fire door is catching on the floor, rubbing against the frame, or failing to close fully on its own, it is no longer compliant. In the event of a fire, a sticking door might be propped open out of frustration, or it might fail to latch, rendering it useless.
But before you reach for the sandpaper or a plane to shave the door down, stop. Altering a fire door can instantly void its certification and break the law.
Here is why your door is sticking, and how it should be fixed.
Common Causes of Sticking Fire Doors
1. Loose or Worn Hinges
Fire doors are incredibly heavy. An FD60 door can weigh upwards of 45kg. Over time, this weight puts immense strain on the hinges. If the hinge screws become loose, or the hinges themselves wear down, the door will drop slightly and begin catching on the floor or the strike plate.
2. Building Subsidence or Shifting
Buildings naturally move and settle over time. Even a millimeter of movement in the surrounding walls can cause the door frame to shift out of square, causing the door to bind against the frame.
3. Swelling from Moisture
Timber fire doors can absorb moisture from the air, especially in areas with poor ventilation, external-facing doors, or newly plastered buildings. This moisture causes the wood to swell, closing the vital gaps around the edges.
4. Failing Door Closers
Sometimes the door isn’t sticking against the frame; instead, the overhead door closer has lost tension or leaked its hydraulic fluid, lacking the strength to push the door into the latch.
Why You Cannot “Just Sand It Down”
When a standard internal door sticks, the standard DIY response is to take it off its hinges and shave a few millimeters off the bottom or edge. Do not do this to a fire door.
Fire doors rely on very precise tolerances. The gap around the top and sides of the door must be between 2mm and 4mm. If you plane the door down, you risk making this gap too large. If the gap exceeds 4mm, the intumescent strips hidden in the frame will not be able to expand enough to seal the gap in a fire, allowing smoke and flames to pass through.
Furthermore, altering the door removes the protective lipping, potentially exposing the combustible core of the door and immediately voiding its fire certification.
The Professional Fix
Fixing a sticking fire door requires a professional. Depending on the cause, the correct fix might involve:
- Replacing worn hinges with certified heavy-duty alternatives.
- Re-packing the hinges to lift the door back into alignment.
- Adjusting the tension and closing speed of the overhead closer.
- In severe cases of swelling or frame distortion, recommending a full replacement.
If you have a sticking fire door in your commercial property or residential block, don’t ignore it, and don’t attempt a DIY fix.
The experts at VYR Doors provide rapid, compliant fire door maintenance across South Wales. We will diagnose the issue and fix it strictly to compliance standards, keeping your building safe and legal.
Contact us today to book a maintenance visit.