June 2018

Alternatives to Gas Torches
WHEN TO MECHANICALLY FIX TO
AVOID FLAT ROOF FIRES
By Warwick Badams of Fixfast.
Gas torches are the traditional method for
fixing bituminous membranes to flat roofs.
But with 11 fires on UK construction sites
every single day, and hot works responsible for
15% of blazes on commercial and industrial
premises, there’s an increasing demand for
contractors to use alternative methods.
In fact, the NFRC’s excellent Safe2Torch campaign
estimates that alternatives are required for at
least 50% of all flat roof installations in the UK.
Safe2Torch identifies a long list of common rooftop
scenarios where the use of gas torches isn’t
appropriate. These are:
• On timber or fibreboard roof decks, upstands or
fillets, even if treated with bituminous primer.
• On old metal roof decks where troughs may
contain debris.
• On insulation that isn’t specifically designed
and tested for use with gas torches.
• Near expansion joints with voids or filled with
foam or fibreboard.
• Near open perpends or any cavities.
• Near cladding, hanging tiles, slates and
thatched roof sections.
• Under pitched sections where tiles overhang
the flat roof.
• Near plastic fascias and soffits.
• Near rooflights of any type.
• In confined spaces.
• At junctions with existing waterproofing where
flammable material may exist (e.g timber, sarking
membrane or DPC).
• Near recently-applied solvent-based coatings.
Above: Illustration shows areas where gas torch use may not
be appropriate.
• Near air vents, ducts, and window and door
sills and frames.
• Near kitchen plant which may be coated in oils.
• Near ducts and trunking which may have
flammable wrapping.
• Near metal or plastic copings and cappings.
• Near plastic pipes, curbs and domes.
Flame-free policies
In addition to this list, many main contractors and
building owners are now adopting flame-free
policies, which prevent the use of gas torches for
any construction process on site, even where
these scenarios are not present.
At Fixfast we want to build on the NFRC’s
valuable Safe2Torch guidance by sharing our view
on the best alternative method to use when gas
torches aren’t appropriate. In these
circumstances, there are two main options –
adhesives or mechanical fixing.
Of the two, mechanical fixing offers the greatest
flexibility for contractors. Many adhesives cannot
be used in temperatures below 5ºC. With the UK
climate, taking into account a rooftop wind chill
effect of -5ºC, this would have ruled out adhesive
roof work on 120 days in 2017 alone.
Mechanically-fixed bituminous membranes are
suitable for both cold and warm roof applications.
Unlike adhesives, there are no temperature
limitations on when the membrane can be installed,
and there is no need to allow for curing time.
They are easy to install, with no need for flames –
you simply use an electric screw gun to fasten the
membrane sheet on to the roof deck or the
insulation layer. Depending on the system chosen,
you can get fixings to suit insulation up to 500mm
thick.
With the right mechanical fixing system, the
energy efficiency of the roofs you install is
preserved using tube washers to prevent thermal
bridging. And some systems are even available
with a performance warranty of up to 40 years, to
ensure the longevity of the buildings you install,
provide peace of mind for your customers, and
protect your reputation.
For many flat roofing applications, use of gas
torches can still be appropriate, provided the
risks are properly assessed and managed. Where
alternatives are necessary, or where a project
requires the specific benefits of an engineered
solution, mechanical fixing offers the best
combination of ease of installation, performance
and cost to help you deliver safe, long-lasting
bituminous flat roofs.
Contact Fixfast
01732 882 387
www.fixfast.com
@fixfast_uk
54 TC JUNE 2018