Colchester Castle Reroofing Works
Colchester, Essex

Colchester Castle is built over the podium of a large Roman temple, likely under Emperor Claudius for the imperial cult in the new colony of Camulodunum. Its developmental path to a full-scale castle was interrupted, as evidenced by the battlements visible in the walls at what would have been the first-floor level. Had it continued, the building would have been three-stages high, (for reference, the Tower of London is four). The royal castle passed to a series of nobles and officials, until it was bought by the Borough of Colchester. In the 1930s its roof was infilled to allow for the expansion of the museum, housed within the castle from 1860. In 2012 extensive refurbishment began, which saw the removal of the 1930s rooflights and the laying over of the existing roof of a synthetic waterproofing membrane.

The immediate issues instigating our scope of works to the castle were increasingly detrimental events that could eventually render the building's use as a public museum untenable:

• Severe rainwater ingress adversely affecting the internal environment of the museum and the ability to continue displaying certain significant Roman artefacts
• Primary fabric deterioration, causing health and safety concerns regarding integrity of roof, walls and floors
• The falling of large masonry pieces into the surrounding public park, causing health and safety concerns and the need to install temporary protective barriers around the museum.

Our proposals will address the above urgent needs including:

• Masonry repair
• Consolidation to wall tops and high-level masonry on the north, east and west elevations
• Overlay and refurbishment of defective detailing and part-failure of the 2011 roof covering including partial relaying to correct falls
• Removal of existing scaffolding and timber perimeter walkways, to be replaced by balustrading
• Remodelling of perimeter guttering around the lantern, replacing membrane with leadwork.

The scope of works also includes:

• Access strategy with clear, contained areas for public and school parties on the roof as well as clearly defined maintenance routes
• Replacement of undersized rainwater outlets
• Development and adoption of a roof for the castle, checking condition, longevity, and sustainability policy for all existing masonry, gutters, drainage systems and coverings.