Client: Plymouth City Council
Plymouth’s Civic Centre is a Grade II listed building, constructed in the late 1950s and opened in 1962 by The Queen. This iconic building formed the principal offices for Plymouth City Council (PCC) until it was sold in 2015.
The Civic Centre’s reinforced concrete frame structure and ‘winged roof’ was innovative for its time. The city was heavily blitzed during WWII and the building is considered to be a nationally important example of post war architecture.
However, this 14-storey reinforced concrete structure has been deteriorating and the perimeter concrete cladding was starting to spall. The perimeter beam and slender external columns had deteriorated to the extent that reinforcement was corroding.
In 2007, JGP were commissioned by PCC to conduct detailed structural surveys, rope access inspections, petrographic and laboratory analyses into the reinforced concrete and its condition.
The Civic Centre is environmentally exposed due to its coastal setting and the high degree of exposure to wind-driven rain. These conditions are favourable to rapid carbonation and the significant ingress of airborne chloride salts. Both of which are significantly detrimental to the reinforcement within the structure. The structural surveys indicated that the depth of concrete cover over the reinforcement was highly variable. This was reflected in areas of decaying rebar. The protective cladding panels and pilasters were also identified to be in poor condition. Cracking and debonding was allowing the ingress of salt and moisture-laden air.
JGP were subsequently engaged to engineer the much-needed remediation works. The repairs and regular structural surveys and rope-access inspections were necessary to keep the building serviceable and safe to use prior to its sale.
Furthermore, JGP designed a safe access route to the building for both the public and staff. This was required to protect against the risk of spalling cladding and plaster from the tower.
The Civic Centre is now under the ownership of Urban Splash. The redevelopment of the site now forms part of the Plymouth and South West Devon Joint Local Plan.