This week's roofing special covers everything from guidance on working safely at height, to who's repairing the roofs of Westminster Abbey. Plus, a look at the classroom roofing of the future …
What's the spec?
St Francis of Assisi Primary School, Notting Hill, London

This outlandish creation is actually a school building. It is one of the first schemes to be completed under the Department for Education and Skills' Classrooms of the Future project, a £10m initiative intended to stimulate innovation in school design.

The building is in fact an observatory. But, in addition to a telescope housed in a rotating rooftop dome, the building contains a chemistry laboratory and a mini biosphere in the ETFE-clad conservatory.

The design by Studio E Architects combines the high-tech ETFE roof at the front of the building with the more traditional a blue, timber-shell roof, constructed by Cowley Structural Timberwork, at the rear.

The curved timber cladding is constructed from a sandwich of Finnish Birch Plywood and Oriented Strand Board pressed into shape before being attached to timber structural ribs. After assembly the units were taken to a local glass reinforced plastic specialist, where the weathering layer of resin and glass-fibre was added before the blue finish was applied.

Project team
Royal Borough of Kensington & Chelsea
Studio E Architects
Structural engineer
Services engineer
Max Fordham & Partners
MPA Quantity Surveyors
Main contractor
Balfour Beatty Construction
Timber shell construction
Cowley Structural Timberwork

Better insulation with polystyrene
YBS Insulation has improved the insulation value of its Therma-Flect expanded polystyrene roof boards to meet the new Building Regulations.

The silver board incorporates graphite, which the manufacturer claims allows a U-value of 0.2 W/m2K with a 150 mm thick board. The gold board is said to be capable of achieving the same insulation value, but with a thickness of only 95 mm.
YBS Insulation 305

Insulating roof halter
Rigidal Systems has launched an insulating halter for its Ziplok standing-seam roofing system. The Thermohalter connects with the side laps of the roof panels to provide a zip-up standing seam detail. This provides a continuous weathertight roof without any through fixings. When used in conjunction with the company's Ziplock roofing system, the roof is said to achieve a U-value of 0.25 W/m2K.
Rigidal 306

Pipe outlet for quicker installation
Single-ply roofing product manufacturer Alkor Draka has produced a pre-bonded stainless steel pipe outlet for flat roofs. The pipe has been designed to reduce the time it takes to install rainwater discharge points for both internal and eaves gutters on flat roofs. The standard 110 mm diameter unit is available in four different styles of stainless steel removable roof guard. A 75 mm unit is also available to comply with German standards.
Alkor Draka 307

Aluminium-beamed roofing system
SGB has launched Coverspan 610, an aluminium beam system designed for temporary roof structures with a span up to 25 m in either a mono- or duo-pitch configuration. The roof can be assembled in situ or pre-constructed on the ground and then craned into position. Waterproofing is provided by PVC sheeting, which is curved around the beam-ends to reduce wind uplift and improve weather resistance. The unit can also be used to create temporary buildings.
SGB Group 308

Flashing unit for SunPipes
Roof-tile manufacturer Decra has added a moulded plastic flashing unit to its Pantile range. The unit is manufactured to incorporate a 300 mm diameter SunPipe, allowing designers to bring daylight into buildings. The moulded flashing replaces conventional lead flashing. The company plans to launch units for SunPipes in other sizes and more tile profiles in the near future.
Decra Roof Systems 309

General purpose board, now with holes
Freefoam Plastics has extended its 10 mm general purpose board range with the introduction of a 600 mm-wide board for deep-soffit applications. The board is available plain or with ventilation holes preformed.
Freefoam Plastics 310

Light, fast tile for low pitches
Sandtoft Roof Tiles has developed an interlocking clay plain roof tile as a cost effective alternative to concrete tiles. The "20/20" needs only 20 tiles to cover a square metre, which the company claims makes for a lighter roof construction and allows faster completion. It can be laid to a pitch as low as 22.5° and is available in four colours: natural red, antique, tuscan and flanders.
Sandtoft Roof Tiles 311

In-line roof vent with clay finish
Stoke-on-Trent-based roof-tile manufacturer Daniel Platt has introduced a natural clay finish in-line tile vent to ventilate roof spaces. It fits flush with the roof, eliminating the need for ventilated soffits or ridge vent tiles. The ventilation unit takes up the space of three tiles, provides 6250 mm2 of free area and is available in five standard finishes; special finishes are also available. The units can also be used to provide ventilation for mechanical extract systems and soil pipe ventilation.
Daniel Platt 312

Treatment to prevent weathering
Acrypol has launched a treatment system designed to counter the effects of weathering and pollution, which causes porosity in clay, concrete and asbestos tiles. Called Nu-Life, the product is available in five colours: red, terracotta, brown, grey and green. The water-based product can be applied using brushes and is dry after about six hours.
Acrypol Products 313

Movers and makers

  • Restoration specialist Norman & Underwood has been awarded the contract to repair the roofs of Westminster Abbey. The work will include replacing the lead on the roof of the south aisle and works to the south-east “triforium” roof. The firm first worked on the abbey in the 1920s.

  • Keybemo’s terne-coated stainless steel roofing system has been used on the roof of the Dunstaffnage Marine Research Laboratory on the west coast of Scotland. The product was specified to cope with the harsh climate and was installed by Thomas Devon.

  • Kelsey Roofing Industries has completed its first building envelope for the John Lewis Partnership after being appointed as a trade-contracting partner last year. The envelope was for a new Waitrose store in Mill Hill, north London.

Information point

Slating and tiling manuals
New NVQ level two manuals on slating and tiling have been published. The manuals by Gerald Emerton cover common materials and methods such as: single lap, variable gauge; double lap, variable gauge and artificial slates and single lap, fix gauge, interlocking and mitred tiles. A forthcoming series of NVQ level three manuals will feature natural slating, random slating, circular work with tiles and circular work with slates. To purchase the manuals call the Construction Industry Training Board on 020-7600 7700.
CITB 314

Heaven’s slate
Eternit Slates has launched the Heavenly Roof guide, which provides product and technical information on Eternit’s slate range. The guide carries details on all the Eternit slate colours and sizes with dimensions, lap and pitch tables and information on the strength and thermal qualities of Eternit Slates. There is also a section on Building Regulations and details of Eternit’s technical advice service.
Eternit Slates 315

Working safely at height
The Height and Access Safety Group has published a leaflet detailing height safety best practice. The guide offers information for those involved in the selection and use of personal protection equipment.
It offers information, advice and best practice on using and specifying PPE equipment and lists the attributes specifiers should expect from manufacturers and suppliers.
HASG 316

Flat roofs explained
Kingspan Insulation has launched the latest edition of its Flat Roof User Guide. The publication provides information on the company’s rigid urethane systems, phenolic products and extruded polystyrene insulation. The updated guide also quotes thermal performance in accordance with the European product standards. Each application is accompanied by illustrated fixing details, product details and the correct thickness of insulation required to meet the required U-values.
Kingspan Insulation 317

Terracotta guide
Hepworth Drainage has published a 36-page guide to terracotta products. The publication covers chimney and flue products as well as ridge tiles, decorative finials and air bricks. Each product is pictured alongside technical drawings, dimensions and Hepworth product code details.
Hepworth Drainage 318

Marley portfolio
Marley Roofing Products has published a brochure detailing its product portfolio. The brochure provides technical information on products such as the plain tile range and the interlocking slate and tile ranges. The publication includes information such as maximum gauge and headlap, minimum and maximum rafter pitch and coverage and weight of laid tiles per square metre. The brochure also contains information on standard constructions.
Marley Roofing Products 319