Client
Plymouth City Council
Value
£ 288k
Sectors & Services
Buildings Repairs & Refurbishment Concrete Repair Coatings Corrosion Control Cleaning & Preparation External Façade Refurbishment Projects
Ballard House is a prominent 1960s fair-faced concrete building located at the south west corner of Plymouth city centre, overlooking the city and forming part of a historically sensitive urban setting.
The building serves as the main council office for Plymouth City Council and sits adjacent to the 19-acre Millbay regeneration area, a major mixed-use development incorporating marina, residential, commercial and educational facilities.
In summer 2024, visible concrete deterioration and areas of spalling were identified across parts of the façade. In response, CRL Surveys was appointed to undertake a comprehensive condition survey to assess the extent of degradation and determine appropriate concrete repairs to safeguard the structure’s integrity and long-term performance.
Services undertaken
- Full concrete condition survey and investigation, including Visual inspections and hammer surveys, Carbonation depth testing and chloride analysis, Cover meter surveys and half-cell potential testing
- Non-destructive testing to confirm cladding ties
- High alumina cement and sulphate testing
- Façade cleaning trials
- Access via cradles with structural calculations
- Controlled jet-washing of concrete surfaces
- Concrete repairs with replicated pebble-dash finish
- Application of anti-carbonation primer
- Application of pigmented Elastocolor coating system
- Establishment of exclusion zones and site safety measures
The project commenced with a full concrete condition survey and investigation, designed to establish the causes and extent of deterioration affecting Ballard House. A detailed visual inspection was undertaken, supported by hammer testing to identify delaminated areas. Carbonation depth testing, chloride analysis, cover meter surveys and half-cell potential measurements were completed on selected elements to assess reinforcement condition and corrosion risk. Non-destructive investigations were also carried out to confirm the presence of cladding ties, alongside specialist testing to determine whether high alumina cement had been used in the original concrete mix and to identify any sulphate contamination.
To minimise disruption and manage costs, testing locations were carefully selected in less conspicuous areas, guided by a robust action plan and comprehensive risk assessment. Following interpretation of the survey findings, CRL was appointed to carry out façade cleaning trials to remove ingrained carbon deposits. A pigmented anti-carbonation coating system was identified as the most appropriate solution for the decorative concrete panels. Multiple colour samples were applied to allow Plymouth City Council to select a shade that respected the architectural character of the West Hoe area.
Access to the façade was achieved using cradles, with Buxton Associates undertaking the structural calculations and determining the precise positioning of support legs on the flat roof. Prior to repairs, the concrete surfaces were carefully jet-washed, with controlled pressures to protect ageing windows and prevent water ingress. A further close visual and delamination survey identified all areas requiring repair. Concrete repairs were then completed by experienced senior tradespersons, working within clearly defined exclusion zones, and finished to replicate the original pebble-dash texture, ensuring a seamless and sympathetic restoration.
Following completion of the concrete repairs, long-term protection of the façade was prioritised to enhance durability and reduce future maintenance requirements. An anti-carbonation primer was applied to all treated areas, providing a robust barrier against carbon dioxide ingress and reducing the risk of future reinforcement corrosion. This was followed by two full coats of Elastocolor, applied strictly in accordance with Mapei’s specifications, with a minimum curing period of 12 hours observed between coats and humidity levels closely monitored.
Approximately 4,000 square metres of architectural concrete were coated using rollers and brushes, allowing precise application across complex detailing. Despite challenges posed by the local microclimate, careful planning ensured consistent coverage and quality. The completed coating system delivers improved resilience, enhanced aesthetics and extended service life, supporting effective asset management and ensuring Ballard House remains protected well into the future.
