When looking at the bridges from the riverside, people have a good view of the length of the Old Bridge, part of which is currently covered in vinyl sheeting. This may look like a convenient place for us to display our logos, but it’s actually got a much more practical use.
Known as ‘encapsulation’ the vinyl sheeting is a continuously bonded skin which is shrunk down with a heat gun to produce a drum tight shelter around the scaffolding. The sheets are ‘welded’ together to create a sealed internal and protected workspace which contains any debris produced. It also protects the surrounding environment, preventing any material from escaping into the air around the bridge or falling into the river. Access to the encapsulated spaces is through zipped doors.
The heat shrinking of the encapsulated scaffold means the sheeting does not flap noisily in the wind and should not tear in a storm. It also provides weather protection and temperature control, making the environment safer and more pleasant for the workforce and ensuring quality of finish during the painting phase of the project. This is important because inside the encapsulated areas paint and corroded steal are being removed by shotblasting. The steel will then be repaired and thoroughly cleaned before being primed and repainted with protective paint.
Installing the wrapping – which is 100 per cent recyclable at the end of the project – is not a straightforward job as it had to be fitted tightly around all the details of the bridge structure and the scaffold itself. The scaffolding and encapsulation were installed by Alltask Limited, appointed by main contractor FM Conway.
We couldn’t be there to photograph the shrink wrapping process, but here’s a video from a supplier so you can see how it works.