Dortek’s Guide To Fire Door Safety

Fire doors are one of the most critical elements of fire protection. They are used to provide compartmentation – in other words, containing fire and smoke for a period of time to allow people to be safely rescued and evacuated.

Fire doors are often the first line of defence in a fire and their correct specification, maintenance and management can be the difference between life and death for building occupants. Despite this, fire doors remain a significant area of neglect and are often the first thing to be downgraded in a specification or mismanaged throughout their service life.

A review undertaken by FDIS certificated fire door inspectors earlier this year revealed the extent of fire door failures being seen on site:

  • Over 61% of fire doors inspected had problems with fire or smoke seals
  • More than a third had incorrect signage
  • 230 fire doors inspected had gaps bigger than 3mm between door and frame
  • More than 20% had unsuitable hinges
  • Almost 1 in 6 had damage to the door leaf.

(Source: FDIS 32)

The most common identified cause of death from a fire incident is being overcome by gas, smoke or toxic fumes. Suffering from the effects of gas or smoke also accounted for one-fifth of all non-fatal casualties in 2013-14. (Source: This reinforces the importance of properly specified, installed and maintained fire doors with intumescent seals that keep smoke from leaking around the edges of a fire door.

Dortek Fire Doors, sectional doors and stacking doors.

Here’s our checklist to help you specify the correct fire doors and keep them in tip top condition:

  • Always use a reputable and competent supplier – many people claim to make fire doors, but only a handful have a properly tested product which is proven to work in a fire.
  • Ask whether the product has been fire tested and demand to see the documentation that proves it (e.g. fire certificate or label).
  • Specifying fire doors with intumescent seals is crucial to prevent smoke inhalation in the event of a fire.
  • It’s not just the door itself that matters. The frame and ironmongery is just as important – they all work together. Only buy exact compatible hardware and components from the same reputable supplier.
  • Saving a few pounds on fire doors isn’t worth it. Consider the cost of damage and loss of life if a fire breaks out. Stick to the specification at all times.
  • Correct installation is as important as buying the correct product – fire doors are a carefully engineered fire safety device which must be fitted correctly so make sure you use experienced installers from a reputable company.
  • Fire doors should be checked regularly, and the more they’re used the more frequently they should be checked.
  • Make sure you use an experienced door company to manage the servicing and maintenance of your fire doors.
  • Only ever replace damaged components with like-for-like. A trained individual should be responsible for this maintenance work.

What’s the difference between Composite and Dortek GRP vermiculite-cored Fire Doors?

Dortek GRP Fire Doors

A Dortek vermiculite-cored GRP fire door is a solid vermiculite or solid reinforced concrete door with a sacrificial outer GRP skin. In the instance of a fire, the exposed GRP surface skin is a sacrificial layer that disintegrates in about 15 mins or less and has zero function in the overall performance of the vermiculite door. In the event of a fire, an integrated intumescent strip on the door expands to captivate the vermiculite core into position in the door frame before the GRP skin on the furnace side falls away.

Dortek GRP vermiculite-cored Fire Doors have undergone over 60 fire tests and achieved fire integrity of 2, 3, 4 and even 5 hours. Compare this to a “GRP composite fire door” where the glued-on GRP sheet is fundamental to give structure to the phenolic core – once the glued outer GRP sheets are burnt away there is nothing left to give structure to the fire core and the door fails after around 30 minutes.

Since 2006, all Dortek fire doors have been tested against the more difficult standards of EN 1634-1 and UL 10-C, in addition to fire testing taken place at Warrington Fire, the same Dortek fire doors have been successfully tested in Singapore, China, Malaysia and France. In stark contrast to the large overall UK market for external composite entrance doors, Dortek does not sell a single door into that market.

Dortek GRP vermiculite-cored Fire Door Design:

  • A one-piece vermiculite core
  • A single coating of liquid GRP (same purpose as paint or varnish)
  • Once piece construction
  • Specific fire resisting resin
  • Integral intumescent

Dortek GRP Fire Door Fire Rating:

  • Up to 5 hours fire rating

Composite GRP Fire Doors

These type of doors are commonly used as entrance doors and are known in the residential building industry as “GRP composite fire doors”. They usually have a fire rating of 30 minutes which is considered good for this type of door. In the event of a fire, the intumescent expands to keep the door in place until the GRP skin falls away.

A GRP composite entrance door is typically a phenolic foam core with a sheet of pre-formed GRP glued to each side, the sheet of GRP is stuck on to give the door some structure and rigidity as well as for cosmetic reasons. This method of panel manufacture is commonly known as “lick and stick” and fire doors made in this manner are typically tested to the standard of BS476.

GRP Composite Door Design:

  • Two preformed sheets of GRP to give the door structure
  • PVC frame (to which sheets are glued to)
  • Phenolic foam core (injected into void between sheet)
  • External intumescent

GRP Composite Door Fire Rating:

  • Typically 30 minutes

GRP Dortek fire doors vs Composite fire doors

          GRP Composite Fire Doors                       Dortek GRP Fire Doors

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