Eliminating the margin for error

Cath McLean from Promat UK explains the benefits of a whole-system approach for effective fire-resistant glazing

Uncertainty and confusion still prevail in the market around the design and installation of passive fire protection measures, particularly fire- resistant glass and the associated
framing systems.

In the pursuit of meeting numerous and sometimes competing project goals – such as value engineering, aesthetics, build schedule, security, noise control and energy efficiency – there must never be any compromise on fire safety. Plenty of technical resources are available online, plus in-depth CPD seminars, but what are the basic considerations when specifying fire-resistant glazing?

Fire resistant glass installed within approved systems withstands the conditions of high temperature, smoke and spread of fire. Various technologies are used, including a modified toughening process, intumescent interlayers and intumescent gels to provide tested levels of fire protection.

Fire resistant glazing will typically provide protection for a period of 30, 60, 120 or 180 minutes. This figure will be displayed next to the following types of protection: Integrity only (E – the most basic), Radiation control (EW – offering a barrier to flames and hot gases, plus some of the fire’s heat), and Integrity and Insulation
(EI – the highest level of protection, providing heat insulation as well as a barrier to flames and hot gases).

Standards and testing
Approved Document B helps to determine where fire protection measures should
be incorporated into a building, and the level of protection, but it is not specific enough to be more than a guide. This leaves the fire safety requirements open to interpretation and puts the onus on the specifier to get it right.

There are a number of important standards to look for when identifying an appropriate glazed fire protection product or system. However these many different standards illustrate the big issue. Standards, advice and legislation are well-intentioned, but how can we be sure that the installed systems will perform as intended in the event of a fire when there is so much room for interpretation and no requirement for the competency of the installer?

Design and construction
Fire-resistant glass is one part of a tested construction, along with the framing materials. It is vital that the materials used at the point of installation are exactly those specified and tested together. This is the only way to ensure compatibility with the required performance. Substitution of similar products could lead to the systems being compromised in the event of a fire. We work with architects to design and specify systems to the appropriate requirement using tested systems.

Aesthetics, light transmission & acoustics
With the right specification, glazed partitions enable designers to balance aesthetics, acoustics, energy efficiency and fire safety. Often there is a desire to increase the natural light levels in areas such as internal office spaces and atria. A butt-jointed glazing system is ideal in these situations, and these are available with EI passive fire protection system plus acoustic insulation. Promat Systemglas is one such solution, with combinations of glass available to increase flexibility and incorporate tinted, coated and patterned glasses. There are also options to include fire rated glass doors within these glazing systems to complete the package.

Acoustic challenges can also be addressed in combination with light transmission and fire safety. This can easily be achieved using a combination of acoustic and intumescent interlayers with the fire resistant glasses within a system.

Cath McLean is segment manager for glass at Promat UK