Cornish Units

Metrotile eGuide
Local Authority & Housing Association
Cornish Units
As specified by:
Metrotile eGuide
Metrotile for
Cornish Units
Metrotile Lightweight Roofing is an extremely
secure and durable roofing system that is suitable
for any rooftop application, from smaller projects
such as garages or home extensions to large scale
new build developments such as schools or retail
parks. Within this brochure, we will look at how
Metrotile roofing has been specified by various
Local Authorities and Housing Associations to
refurbish the roofs and cladding of their Cornish
Unit homes.
If you have any questions about Metrotile, please
visit our website at www.metrotile.co.uk, email us
on [email protected] or call us on 01249
658514.
Metrotile Product Profile
Metrotile Shingle .450
Gallery: Metrotile Shingle
Based on the classic North American
timber shingle design, Metrotile Shingle
is a simple and elegant solution for any
roof project. Offering the rooftop quality
and style for which Metrotile is
renowned, Metrotile Shingle has been
designed with a unique “hidden fix”
system that also enables the product to
double as an excellent vertical cladding
solution.
This is because the hidden-fix design
leaves no nail exposed, preventing
The Metrotile Shingle profile
rainwater from corroding the nails, a
common weakness of traditional vertical
cladding.
Metrotile Shingle is available in five
colours, and can be fixed from vertical,
down to a minimum pitch of 15°. It is the
ideal profile for those looking for a
simple and elegant roofing or cladding
solution
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Case Study
Tai Calon HA
Gallery: Cornish Units, Blaenau,
Gwent
There is an abundance of 1950’s prefabricated Cornish Unit homes found
throughout the UK, many of which are still within housing stock held by Local
Authorities and Housing Associations. When undertaking the refurbishment of
their Cornish Unit stock, Tai Calon Housing Association turned to Metrotile to
supply the Metrotile Shingle Lightweight Roofing and Vertical Cladding system
to replace the mansards, following the successful application of the product as
vertical cladding on recently refurbished homes. The result was a stunning
The Metrotile Mansard blends with the different
rooftop material.
rejuvenation of the units, complimented by the vandal resistance and insulation
benefits provided by the Shingle system.
John Lewis, the Senior Technical Officer for Blaenau Gwent County Borough
Council has stated:
KEY POINTS
1. Metrotile Shingle used to replace
mansards.
“I would be more than happy to talk to any other Local Authority or Housing
Association to highly recommend this system”
The application of Metrotile also placed less strain on the supporting structure
2. Specified for vandal resistance and
insulation benefits
than the traditional materials did, which is very important given the nature of the
3. Senior Technical Officer highly
recommends the system.
to last up to forty years - and with a Metrotile installation, they are now
4. Less strain on aging structure of Cornish
Units.
Cornish Unit’s architecture. At the time of construction they were only expected
guaranteed weatherproof for another forty years!
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Specification
Re-roof with Metrotile Shingle
Strip off existing tiles, trims, flashings, felt and battens and remove from site. Inspect existing
timber trusses for damage or deterioration. Remove any redundant nails, staples, etc. Remove any
debris from gutters and voids in “Mansard” areas and remove from site. Assuming the existing
Mansard trusses are the standard 75mm x 50mm @ 400mm centres. Supply and fix “Cellotex” or
Phenolic Board or similar rigid foil faced insulation board , cut to fit firmly between the rafters, but
leaving a 25mm air gap between the insulation board and front or top of the rafters.
Supply and fix to existing Mansard rafters and according to manufacturers instructions Metrotile
Vapour Permeable Underlay (VPU) in accordance with BS5534 2003, 0.5mm thick and 125gm2
lapped horizontally. Supply and mechanically fix to existing Mansard rafters, new approved quality
sawn and treated 38 x 25mm timber tiling battens at 250mm gauge (measured from front face of
batten to front face of batten) to accommodate “Metrotile Shingle” steel aggregate coated roofing
tiles. Joints in battens to meet half way across the top of rafters and to be staggered as Standard
Code of Practice.
To window cheeks supply and fix Metrotile Flat Sheet cut and bent over tiling battens with a 25mm
welt to prevent water ingress. Alternatively, re-dress or renew, in accordance with supervising
officers instructions, Code 4 lead flashings around windows and adjacent abutting roofs (some
adjacent roof tiles may have to be removed and replaced to facilitate this) to replace worn lead or
aluminium trims.
Supply and fix in accordance with manufacturers instructions “Metrotile Shingle” steel roofing tiles
and accessories as per NBS type specification . If required, a new UPVC soffit and fascia should
be supplied fixed to end of rafters and to a new vertically fixed 50 x 50mm batten,Hilti fixed to
concrete walls. Supply and fix new UPVC rainwater goods. Rainwater downpipes to discharge into
existing water outlets. On completion of roofing works, the site should be left clean and tidy and
any debris should be cleared from site and taken to an approved tip for disposal.
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Approximate
Costings
Labour, Materials and
Scaffolding:
Approximately £21,000
for a block of four (for
maisonettes)
Approximately £16,000
for a pair Cornish Units
oer Half Pair
Cornish Units:
Main roof and mansard
including lead, flat
sheets for windows and
any cover flashings excluding scaffolding,
fascias, soffits and
gutters:
£7,450
Pair approximately
£14,000
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Insulation Details for
Roof and Mansard
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Mansard
Detail
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Eaves
Detail
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Typical
Half Pair of Cornish Units
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Window Abutment
With Flat Sheet
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Window Abutment
With Easy Soaker
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Gutter Bonding at
Joint Between Homes
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Cornish Dwellings
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Approximate
Quotations (Shingle)
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Approximate
Quotations (Shingle)
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Approximate
Quotations (Shingle)
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Metrotile Product Profile
Metrotile Bond .450/.900
Gallery: Metrotile Bond
The Metrotile Bond profiles are
designed to be aesthetically
indistinguishable from traditional clay
pantiles, so they can offer the same
great visual appeal, with all of the
additional benefits lightweight steel
roofing provides. Metrotile Bond is
available in six colours and pressed from
high grade Aluzinc-coated steel standard for all of our profiles. In
addition to our traditional granulated
finish, we can now offer elegant Matt
Brown and Gloss Black finishes with a
The Metrotile Bond profile
non-toxic powder coating.
When dry-fixed to the roof, Metrotile
profiles are overlapped and fixed via a
cross-nail method that provides
excellent vandal resistance, durability,
protection and unmatched resistance to
wind lift. Each tile is the equivalent of
eight conventional roof tiles and may be
fixed from vertical right down to a 10
degree pitch.
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Case Study
Wakefield and District Housing Association
Gallery: Cornish Units, Normanton
Wakefield and District Housing Association manage the Cornish Units at Willow Crescent,
Normanton and have invested in a renovation program to boost the standards of each home. With
WDH’s project, each home has increased energy efficiency due to work upon the roofs and walls
in addition to becoming more aesthetically pleasing.
WDH consulted architects NPS and roofing contractors Ultegra Services regarding the best
materials for the refurbishment. The ideal material for the roofing and mansards needed to look
traditional and keep the look and feel of the units and despite the refresh, each unit needed to
blend in with the surroundings yet maintain the unique look that Cornish Units are known for. Each
A stunning red Metrotile Bond installation
resident was also allowed to choose their own rooftop colour, adding a touch of character to the
already distinguishable Cornish Homes at Willow Crescent in the process.
Metrotile Lightweight Steel Roofing Systems were specified for the replacement of both the
rooftops and mansards, offering each home the many benefits that Metrotile is known for. The light
weight of each profile places less strain on both the supporting frame of the homes and the
KEY POINTS
1. WDH Invested in a home renovation
program.
foundations. For homes that were built as a temporary housing measure, this will help increase
their life expectancy even further. In addition, using Metrotile has helped to boost the insulation at
the properties, with residents already noticing a reduction in their heating bills.
2. Metrotile specified by architects NPS and
installed by Ultegra Services.
Metrotile worked very closely with all involved. The roofs were installed by contractors Ultegra
3. Replaced roofs and mansards, increasing
insulation, security and improving
aesthetics.
“Metrotile is a modern company with old-fashioned customer service values. Unlike many other
4. Reduced strain on supporting structure.
Services and their Business Development Manager, Glen Leatherbarrow, states;
companies, they go one step beyond to help. They work ‘with’ you instead of for you and their
after sales care is second to none”
With Metrotile roofs and mansards installed, the residents at Willow Crescent can look forward to
forty guaranteed years of their new roofs and beyond.
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Specification to Re-roof
Mansards on Cornish Units with Metrotile Bond
Strip off existing tiles, trims, flashings, felt and battens and remove from site.
Inspect existing timber trusses for damage or deterioration. Remove any redundant nails, staples, etc.
Remove any debris from gutters and voids in “Mansard” areas and remove from site.
Assuming the existing Mansard trusses are the standard 75mm x 50mm @ 400mm centres. Supply and fix “Cellotex” or Phenolic rigid
foil faced insulation board , cut to fit firmly between the rafters, but leaving a 25mm air gap between the insulation board and front or
top of the
rafters.
Supply and fix to existing Mansard rafters and according to manufacturers instructions new Metrotile breathable underlay (VPU) in accordance with BS5534 2003, 0.5mm thick and 125gm2 lapped horizontally.
Supply and mechanically fix to existing Mansard rafters, new approved quality sawn and treated 38 x 25mm timber tiling battens at 370
mm gauge (measured from front face of batten to front face of batten) to accommodate “Metrotile” steel aggregate coated roofing tiles.
Joints in battens to meet half way across the top of rafters and to be staggered as Standard Code of Practice.
Re-dress or renew, in accordance with supervising officers instructions, Code 4 lead flashings around windows and adjacent
abutting roofs (some adjacent roof tiles may have to be removed and replaced to facilitate this) to replace worn lead or aluminium trims.
A
proprietary bonding gutter should be introduced at joint between housing association and private houses.
At window cheeks, Metrotiles should be turned up against the window cheeks, and a cut down, scribed (to fit 3 courses of tiles) “Metrotile” side wall” flashing should be fixed, to trim the abutment between tiles and window and a code 4 lead flashing could be used,
dressed over side wall flashing up stand, and used to cover entire window cheek supply and fix in accordance with manufacturers instructions “Metrotile” steel roofing tiles and accessories in accordance with Metrotile fixing instructions and specification.(see roof specification) If required, a new UPVC soffit and fascia should be supplied fixed to end of rafters and to a new vertically fixed 50 x 50mm batten,
hilti fixed to concrete walls.
Supply and fix new UPVC rainwater goods. Rainwater downpipes to discharge into existing water outlets.
On completion of roofing works, the site should be left clean and tidy and any debris should be cleared from site and taken to an ap19
proved tip for disposal.
Specification
Metrotile Bond cont...
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Specification
Metrotile Bond cont...
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External Links
Further Information and Contacts
Tap on the relevant boxes below to read
further information at Metrotile.co.uk
BOND
SLATE
Metrotile UK Ltd
Unit 3
Sheldon Business Park
SHINGLE
Sheldon Corner
Chippenham
Wiltshire
ROMAN
SN14 0RQ
t: 01249 658514
e: [email protected]
ACCESSORIES
w: www.metrotile.co.uk
CERTIFICATIONS
CAD LIBRARY
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