Glass: Insulation or Integrity. How Do I Specify This in Fire Doors?

Chris Robinson , Aug 28, 2020 4:28:36 PM

When it comes to glass in fire doors, deciding between insulation and integrity (or both) can be a difficult prospect, particularly when significant variation in costs are involved.

Both have their merits; One providing a suitable and certified barrier against fire penetration, the other providing this and insulation, too, albeit for a larger cost.

Your building’s fire strategy may dictate your choice and it may be necessary to specify a fire door with both integrity and insulation glass in certain situations, but be mindful of the costs.

This blog aims to clarify the common misconceptions around glass for insulation and integrity and should hopefully provide a clearer understanding for anyone involved in the specification of fire doors.

Read on to find out more.

The Difference Between Integrity and Insulation

Integrity glass will stop fire penetrating through the doorset or screen, but it will not prevent heat penetration, and this will eventually cause material ignition on the opposite side. With integrity only glass, there is a risk of serious burning if touched.

Insulation glass, on the other hand, will stop the transfer of heat in the event of it being touched during a fire.

In most cases, unless explicitly required otherwise, a doorset will provide integrity only. By specifying a doorset with both integrity and insulation, you will significantly drive up overall cost.

However, we will explore situations when both integrity and insulation glass may be needed.


When Would You Need Both Integrity and Insulation Glass?

To put this into context, we’ll share a story from a recent supply and installation at a Student Accommodation facility.

Originally, the building had two fire escapes. To reduce the cost of two doorsets having to be fitted, the developer omitted a fire escape and amended its fire strategy accordingly. This, by the way, was perfectly acceptable and well within building regulations.

However, as there was now only one fire escape, the specified fire doorsets within the fire escape routes needed to have both integrity and insulation glass. This increased the cost of the glazing within the screens, and doorsets on the fire escape route exceeded £40,000.

Whilst the developer achieved a saving, the contractor stood the cost of the increased protection.

When reviewing your fire strategy, attention must be paid to the doorsets and screens within the escape corridors. It is often easier to understand – and certainly more frightening – when these glass specifications are compared side by side in a fire situation.

In the horrific situation of a fire, you need to make your way to the exit. Despite proper planning and carful considered construction, smoke has managed to fill the escape corridor. You cannot see. smoke has filled the upper part of the corridor and you are forced to crawl towards the exit. It is natural to keep close to a wall rather than have no direction in the middle of the room. The wall is constructed from insulated materials up until you reach a screen. The screen with the insulated glass will allow you to continue to feel you way towards the exit. It doesn’t bear thinking about touching an uninsulated piece.

When is it ok to just have Integrity Glass?

It is by no means mandatory to have both integrity and insulation glass. In many situations (and indeed the majority of situations), It is perfectly acceptable to specify integrity glass only.

For example, if the glass panel is above a certain height, you would normally only require integrity glass. It is unlikely that a person will come into contact with the glass that is above 1 metre.

Different Sizing Requirements

Of course, no two doorsets are the same. Many of our clients require bespoke fire doors. If this is the case, various considerations need to be taken.

If you require a larger piece of glass but can’t get fire performance certification on an integrity glass, changing to insulated glass may allow you to achieve your visual aims.

At RW Joinery, we are more than happy to provide you with clear advice to ensure your door meets specification, whilst adhering to your unique design requirements.


Specifying for integrity or insulation can be a challenging prospect, so we hope this post has helped to alleviate any misconceptions.

If you require further information on fire performance glass for your fire doorset, don’t hesitate to speak to an expert today.



Previous Next

Trusted & Accredited

RW Joinery - firedoor systems and bespoke joinery - Get in touch

Talk To An Expert About Your Project Today

Whether you're simply looking for more information or a quote for your next project - one of our trained experts is on-hand to answer any of your queries! 

We'd love to hear from you.