Innovation in techniques: New flood defence wall with special features - stone render-effect finish and built-in habitats

22 November 2021. A section of our recently completed flood defence wall at Aust Wharf Road has some special and unusual features. 

The section is part of a stretch of reinforced concrete wall at the most northern part of our project. It has a stone render-effect finish on one side and, on the other, facing onto the Severn Estuary, built-in habitat shelves for plants. The shelves are made from oak. Natural materials make a better and more sustainable habitat for many reasons. They suit small amounts of natural planting which flourishes; invertebrates prefer them; and they are also renewable, durable and strong. 

The stone render-effect finish was a design response to comments from local residents, as well as South Gloucestershire Council’s technical officers, and the requirements of the planning application. The location of the wall is a rural area, overlooked by homes. Officers and neighbours wanted a structure that fitted with these surroundings. 

In response, we devised a design for a stone render-effect finish that would look natural. We then sent this to a form liner manufacturer. Form liners are the liners, or moulds, used in the preparation of designs of concrete walls. As they are available in many different shapes, the manufacturer was able to recreate our design. The resulting finish has a stone and masonry texture with a horizontally running pattern of ‘rocks’ of different sizes. 

The render-effect finish also has considerable environmental benefits. It has meant we have avoided importing stone material, reducing CO2 emissions in the construction process. The finish makes the wall much easier to maintain compared to stone which would have needed repairing over its lifetime. 

As we pride ourselves on being good neighbours, we are delighted that the design fits well with its surroundings, offers a habitat for plants, and is environmentally friendly.