September 2019

Fire Safety
FIRE SAFETY REGULATIONS –
YOUR QUESTIONS ANSWERED
Rob Firman, Technical and Specification Manager at Polyfoam XPS, answers frequently
asked questions relating to fire safety regulations and flat roofs.
1What document should I refer to for fire
regulations? National Building Regulations
in the UK regulate fire safety. Guidance on
complying with the regulations is set out in
accompanying documents, published by the
Government of each country. The aim of each
country’s regulations are all broadly the same,
but solutions presented in the guidance
documents may vary.
England and Wales each have their own version of
Approved Document B, Volumes 1 and 2. In
Scotland the guidance is found in Section 2 of the
Technical Handbooks, while in Northern Ireland it is
Technical Booklet E.
2What does the guidance cover? The
guidance covers external and internal fire
spread, as well as access for fire and
rescue services, means of escape, and the fire
performance of internal linings. Solutions for any
given project will differ depending on the building
type, its use and occupancy, layout, height and
construction, as well as the distance from
surrounding buildings.
When using construction
products to comply with the
regulations, contractors should
be aware of the reaction to fire
performance of individual
components, and the fire
resistance of a complete element
build-up or system.
3What is reaction to fire? Reaction to fire is
a measure of how a product behaves when
exposed to a fire, and how it contributes to the
fire as it decomposes as a result of that exposure.
“BS 6229:2018 provides
useful guidance and
depending on the level
of complexity, advice
may also be sought
from a fire engineer or
other specialist”
Left: Rob Firman, Polyfoam XPS.
Products are classified according
to EN 1350. From best to worst
performing, the Euroclass
system is: A1, A2, B, C, D, E
and F. For classifications from
A2 to E, a designation for the
production of smoke and/or flaming
particles are added.
European classifications should be the standard
method of declaring performance, but it remains
common to see national designations used, based
on testing to BS 476-6 and -7.
4What is fire resistance? Fire resistance
has three aspects, all measured by the
number of minutes that elapse during
standard tests. ‘Resistance to collapse’ (R) applies
to loadbearing elements only, ‘resistance to fire
penetration’ (E) is also referred to as integrity, and
‘resistance to the transfer of excessive heat’ (I) is
otherwise known as insulation.
A construction element may need to meet all three
aspects, in which case the performance would be
written REI 30 (or 60, 90 or 120, depending on the
period of resistance achieved/required).
‘EI’ relates to an element that is not loadbearing,
and sometimes E alone is required – again, both
are followed by the number of minutes.
“Applying general
principles to buildings
where specific
provisions are required
risks compromising
fire safety”
80 TC SEPTEMBER 2019