Colchester Castle, Grade I and Scheduled Monument

Colchester Castle – Reroofing Works

Introduction

Colchester Castle is a Norman Castle and is currently a museum, exhibiting local history collection. The Castle passed into public ownership in the early 20th and the gardens and the surrounding fields became a municipal park in the late 19th century.

Brief History

Colchester Castle is built over the podium of a large Roman Temple that was most likely built in the reign of the Emperor Claudius for the imperial cult in the new colony of Camulodunum. However, the building's developmental path to a full-scale castle was interrupted, evidenced by the battlements visible in the walls at what would be the level of the first floor. In the end, the building would be 3 stages high, as opposed to four, as in the Tower of London. The royal Castle passed to a series of nobles and officials, until it was eventually bought by the Borough of Colchester. In 1930s, the roof of the castle was infilled to allow for the expansion of a museum that had been housed within the castle from 1860. In 2012, extensive refurbishment works began, which saw the removal of the 1930s rooflights and the laying over of the existing roof with a single-ply Sarnafil waterproofing membrane.

Proposal

PRS Architects have been appointed to assist Colchester City Council (CCC) and Colchester and Ipswich Museum Services (CIMS) to determine essential works required to the Castle.  The immediate issues that instigated this work were the following increasingly detrimental events that could eventually render the building's use as a public museum untenable due to the following:

• Severe rainwater ingress that is adversely affecting the internal environment of the museum and the ability to continue displaying certain significant Roman artefacts
• Deterioration of the primary fabric of the building, causing health and safety concerns, regarding the integrity of the roof, walls and floors
• The falling of large pieces of masonry 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 very urgent needs of Colchester Castle 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; Relaying selected areas of the existing roof to correct falls; Removal of existing scaffolding and timber perimeter walkways; Installation, if required of a new balustrading to replace existing scaffold tube balustrading and remodelling of perimeter guttering around the lantern substituting the Sarnafil for Lead work. The scope of works also include:

• Provision of an accesses strategy with clear and contained areas for public and school party access on areas of the roof as well as clearly defined maintenance routes.
• Replacement of undersized rainwater outlets
• The development and adoption of a Colchester Castle roof, checking condition, longevity, and sustainability policy for all existing masonry, gutters, drainage systems and coverings