RESEARCH INTO EXAMPLES OF ROOF - PART A

1. The Sliding Roof at the New Wembley Stadium

2. The Millennium Dome

The sliding roof remains an integral part of the design for the

new Wembley. Computer models have been made of air

movement and sunlight on the existing pitch and the unique

moving roof designed for the new Stadium.

This will be left open between events but can be moved to line

up with the touchline within 15 minutes, ensuring every

spectator is sheltered during an event.

A further bonus is an improved TV image for fans watching at

home. In bright sunlight the roof can be withdrawn to allow

clear TV pictures uninterrupted by heavy shadows on the pitch.

At 3pm on Cup Final day, for instance, only the two southern

corner flags will be in shadow. (This is from the Wembley

Stadium Press Release - This was not the case on Cup Final

Day at 3pm! - Ed)

The roof of the Dome is a huge cable net, 320m in diameter and

clad in 80,000m2 of tensioned PTFE coated glass fibre fabric. It

is an innovative feat of engineering yet simple in concept.

Twelve 100m high steel masts extend from the roof to support a

tensioned net of steel cables, arranged radially on the surface of

the Dome and held in place by hangar and tie-down cables at

25m intervals. An inner layer of covering reduces thermal gain

and improves thermal and acoustic performance.

3. Energy-Efficient Roof Tops Off Spectacular Cowboys Stadium

4. The retractable roof over Wimbledon’s Centre Court

A vinyl roofing system from Sika Sarnafil totaling 640,000 sq. ft. was

used to cover the massive, newly-completed Cowboys Stadium in

Arlington.

Sika Sarnafil has more than 45 years' experience producing single-ply

vinyl roofing and waterproofing systems — systems known for superior

performance with minimal environmental impact.

At Sika Sarnafil, Sustainability starts with Performance. All Sarnafil

systems are noted for durability and longevity. These systems require

minimal maintenance, may be recycled, and positively impact a building

owner’s Return on Investment.

The retractable roof over Wimbledon’s Centre Court is a type of ‘folding fabric concertina’.

This allows the roof to be folded into a highly compressed area when not in use over the court.

About 5,200 square metres of a very strong, flexible, translucent waterproof material will be used

for the roof. The retractable roof is divided into two sections with a total of nine bays of structural

fabric — four bays in one section and five in the other. Each of the nine bays is clamped on either

side by prismatic steel trusses. There are 10 trusses spanning approximately 77 metres across the

court. The ends of each truss are supported by a set of wheels that move along a track positioned on

the new ‘fixed’ roof of the Centre Court.

In preparation for closing the roof, one section is parked in its folded state at the north end of the

court while the other is parked at the south end. A combination of hydraulic jacks and arms form

the mechanism for closing the roof. The mechanism moves the trusses apart and, at the same time,

unfolds and stretches out the fabric between the trusses over the court until the two sections meet in

an overlapping seam above the middle of the court. The arch shape to the tops of the trusses helps

the structure to withstand loading from elements such as snow and wind when the roof is stretched

and closed over the court. The shape also assists in providing a cleareance of 16 metres for high

balls. The roof has been designed to close in under 10 minutes. If the roof is being closed for rain,

court covers will protect the grass in the usual way while closure is in progress.