Tesco Annan was our first project which ignited our partnership with Mannings Construction Ltd. There was an issue with flooding in the carpark as the water couldn’t permeate through the stone efficiently to be taken away by the main sewer line. We were instructed to lift the blocks, install the new drainage system, clean and then relay the blocks. This process is nicely illustrated below…
During our time in Annan we experienced a high volume of rain, risking delays to works and adding variations such as pumping water out of trenches. It required traffic planning and a strict schedule of works on designated plots. This allowed the store to maintain it’s usual opening hours. To avoid disruption during the busy Christmas period our determined team also conducted night works.
Section 1 from start to finish
Polystorm PSM1 Crate
A major aspect of the anti-flooding system designed for Tesco Annan was the use of Polystorm PSM1(soakaway) Crates. It is manufactured using 90% carefully selected, recycled materials but has an impressive 61 Tonnes/m2 compressive strength meaning it is ideal for trafficked areas such as a car park.
The crate provides surface water retention, infiltration and attenuation. This means that it helps slow down the flow of the water and distributes it effectively to the surroundings alleviating pressure on the drainage and helps prevent localised flooding.
As you can see above, the crates are wrapped in a non-woven geotextile, this is a permeable fabric that slowly filters water through the crates and stops unwanted material to enter.