Waterproofing of a double-wall flood defence to withstand tidal surges from the Firth of Clyde at Rothesay, on the Isle of Bute.

The challenge

Despite the sea front being in a sheltered location, an urgent solution was required to withhold floodwater overtopping the sea wall at Rothersay.

Southerly winds combined with a rising tide had increased flood tide and funnel water up the Firth of Clyde, causing a tidal surge leading to flooding. Due to climate change, this increase in water means that flooding now occurs nearly every year. A permanent, effective solution was now needed to protect the sea frontage, buildings and environment from flood damage.

The Xypex solution

A double stone-faced sea defence wall was constructed with a maximum height of 1.5m. A reinforced concrete infill was placed between the two walls of stone to give the structure strength. Xypex Admix was added to the concrete at the batching plant prior to placement for durability purposes, as Xypex will seal the concrete to the ingress of water and aggressive chloride ions that would corrode the reinforcing steel and degrade the concrete. Xypex is providing maintenance free concrete protection in this harsh marine environment.

Xypex Admix C Series – Concrete infill between the twin block sea defence wall

The results

The proven ability of Xypex to withstand water and chemical penetration within the life of the concrete made it the perfect solution for this crucial seawater defence