Roof Refurbishment of One of the Most Iconic Listed
Buildings in Wales by the Mastic Asphalt Council (MAC)
Mastic asphalt is often recognised for its
longevity and durability and an application
at National Museum Cardiff certainly
demonstrates this as the roofing system
has provided a remarkable 109 years’
weatherproof protection before requiring a
full roof refurbishment.
Long-standing Mastic Asphalt Council (MAC)
member Cardiff Asphalt is currently carrying
out a major roof renovation at the museum
which houses three million objects across
art, archaeology and geology, as well as
library and natural history collections - about
half of the national collection of Wales. The
museum forms part of the wider network of
National Museum Wales.
The whole of the first floor is dedicated
to Wales’s national art collection, from
paintings and drawings to sculpture and
ceramics. It features one of the best
collections of Impressionist paintings in
Britain and leading international artists of
today.
Mastic asphalt was applied to the museum
roof in 1910 when the building was first
erected and only patch repairs have been
carried out since. Mastic asphalt’s seamless
composition means it can easily be spot
repaired, eliminating the need for wholesale
replacement for many years.
It was decided to carry out a full roof
refurbishment with mastic asphalt to protect
the national collection by improving roof
watertightness, fire safety and environmental
conditions. As part of the renovation works,
new chillers are being installed for the air
conditioning system to help conserve the
national collection and urgent electrical work
is also being carried out.
The roof has a surface area of 1,200m2
and with a roofing contract value of
£132,000, the renovation work is expected
to run for up to six months. Cardiff Asphalt
has been commissioned to carry out the
roof refurbishment on behalf of WRW
Construction. Mastic asphalt was specified
64 - www.refurbandrestore.co.uk
once again due to its exceptionally long
lifespan, proven performance and suitability
for use on listed and heritage buildings.
The whole roof has been protected with
scaffolding and a huge cover to enable
Cardiff Asphalt to continue the works, even
in adverse weather conditions over the
winter period.
The mastic asphalt system specified is
a specially formulated roofing solution
that uses advanced polymer technology
to provide long term durability, increased
fatigue resistance, improved temperature
stability and ease of installation. Its low
temperature flexibility ensures that the
system can be installed in cold weather.
Mastic asphalt’s green credentials were also
an advantage for this project, as it is carbon
neutral and when it has reached the end
of its useful life, it can be recycled or used
as roof screed. Ten years ago the mastic
asphalt sector became the first industry
in the world to achieve the CarbonZero
standard.
Fire safety was another consideration
and the high mineral content of mastic
asphalt renders it virtually incombustible.
Mastic asphalt fulfils all the external fire
resistance required for a roof covering
and achieves the highest rating (AA) when
tested in accordance with BS 476: Part 3.
It has also been tested in accordance with
draft European standards prEN1187-1 and
prEN1187-2. No significant spread of flame
was observed and no flame penetration
occurred.
As mastic asphalt is laid in molten form,
it is often confused with other types of
waterproofing membrane that require naked
flame or torch on application. In reality, there
is no naked flame at the point of installation
and because mastic asphalt is so highly
flame resistant, there is little or no potential
of fire risk.
Antony Ryan, Director of Cardiff Asphalt, said
the company was very proud to have secured
a contract of this magnitude in their home
city.
“The National Museum Cardiff is an iconic
building in Wales and we are extremely
privileged to have been selected to carry out
this work. The project does come with its
logistical challenges. For example, access
to the roof is difficult and the museum is
located in such a busy area of Cardiff that
parking and unloading can be problematic
and only certain roof areas are available to
asphalt at any one time as the museum is
remaining open to visitors from 10am-5pm
whilst the roof work is being carried out.
In addition, the project is very physically
demanding as the asphalt needs to be
carried or barrowed from the location of the
asphalt mixer machine.
“This project also requires a great deal
of expertise in the installation of mastic
asphalt, due to the location of domed areas
and high upstands. Mastic asphalt lends
itself to this type of project as its flowing
characteristics make it ideal for surfaces
which are complex or with protrusions,” he
continued.
To fulfil the contract, family-run Cardiff
Asphalt has recruited two new apprentice
labourers to expand the team. Cardiff
Asphalt has been in operation for over 50
years and Antony Ryan and his wife Sarah
took the business over from Antony’s father
Tom when he retired.
Antony concludes: “I’ve been a mastic
asphalt applicator for 34 years now and
the National Museum Cardiff counts as
one of the most prestigious contracts I’ve
personally been involved in. It perfectly
demonstrates our expertise in refurbishing
heritage and listed buildings and it’s fantastic
that it’s such a landmark in our home city.”
masticasphaltcouncil.co.uk