Paints & Varnishes For Timber
Paints For Steel
Using Intumescent Materials to Increase Fire Resistance in Doors

In the event of fire the destructive forces acting on your doors obviously include high temperatures and the flames themselves, but gases are also heated. These gases expand, and create higher pressures than normal. The natural tendency is for the gases to flow from these higher pressure spaces into lower pressure spaces, thus helping the spread of the fire. Under normal daily conditions however a door still needs to retain its looks and functionality. The main things to consider therefore when trying to improve the fire resistance of e.g. timber doors are:

  • In a fire a door is likely to fail first by distortion rather than burning through so both eventualities need to be considered when upgrading.
  • The door appearance and any ornate features may be important to retain and it may be difficult and inconvenient to have to take a door off of its hinges in order to upgrade its fire resisting properties.
  • The pressurised gases caused by the temperature of fire will try to find their way through gaps in the door / door set. Smoke (hot and cold) will also pass through gaps. This needs to be considered in the overall upgrading plan.
  • The complete fire resistance of any door assembly is actually down to a combination of preventative planning and measures taken on the frame, the door ironmongery and the actual door itself.

The Gaps

Intumescent Seals such as Fireplug Intumescent Strips (which have a protective PVC sleeve) can be applied for example to the edge of the door leaf or on the actual face of the door frame itself. It is also worth noting that there can also be a gap between a door frame and the wall which can be exploited by fire although these particular gaps are generally hidden architrave. Ideally Intumescent Fire Seals should be (should have been) fitted to the back of the door frame itself before it was installed. Intumescent Seals react to high temperatures by expanding and therefore closing gaps in the door sets and frames.

Upgrading the The Door(s)

The Fireplug FUS door upgrading system (for timber doors) is simple, effective, and involves the use of 3 different coatings:

1. Fireplug CFPM – a 0.5mm thick intumescent paper.
2. Fireplug ICT – a water based acrylic intumescent coating.
3. Fireplug TSC – a sealing coat to protect against mechanical damage and moisture.

The first part of the process of using this system means ensuring that the door surface is as clean as possible to aid adhesion e.g. rubbing with sandpaper and wiping with a cloth with white spirit.
After brushing on a coat of ICT (the acrylic) the CFPM (paper) should be cut to size and applied to the door, and then coated with another layer of CFPM. After this a double coat of ICT can be applied. After all of this has dried the TSC (sealing coat) can be applied – this may require 2 coats.

Complete Fire Protection Ltd. Unit 2, Ferry Steps Industrial Eastate, Albert Road St Philips, Bristol BS2 0XW
Tel 0117 971 1917 Fax 0117 971 1727 or for more products, information and support email us.