Summary = Conservation works to a medieval castle in Saffron Walden Phases one and two approximately £600,000. Soft capping was installed to protect late Norman castle walls

Location = Saffron Walden, Essex

Challenge = Protect the walls from thermal and moisture fluctuations.

Solution = The castle ruins are exposed to the weather and are deteriorating as a result. Due to falling rubble, it was unsafe for members of public to enter the castle walls.

Going back as far as the late 1970’s Bakers have carried out conservation works to this medieval castle in Saffron Walden.

Built around 1141, the Grade I Listed Scheduled Monument comprises of the substantial ruined walls of a Norman keep, which are exposed to the weather and constantly under threat from further deterioration.

The restoration and conservation work carried out by Bakers over the recent years has stabilised the flint-rubble walls, to ensure it is safe to open Walden Castle to the public.

Phase one started in March 2017. It involved removing any weeds from the masonry, using strong botanical weed killer to remove any roots. Bakers’ sister company, Collins & Curtis Stone Masonry Ltd which has a factory in Ipswich, Suffolk worked closely with Bakers to source matching natural stone to replace any missing pieces.

Sample areas were used to identify the mortar mix and colour, to ensure the new mortar applied will be the best possible match to the existing mortar. Loose mortar was raked out, before being pointed with the matching new lime mortar which had been approved by an accredited conservation architect.=Scaffolding was used to access the upper sections of the masonry.

Phase two involved conservation to the east and south curtain wall. It consisted of similar works to phase one, together with rebuilding the internal arch and pier to provide greater stability to the structure. The visible wall surfaces were also stabilised by replacing cement mortar with lime mortar. Bakers also installed soft capping, comprising of grass turf to the top of the castle walls to help prevent further erosion caused by the adverse weather conditions.

The soft capping installed by Bakers is thought to be the first of its kind in East Anglia, which consists of harvested natural turf, over a layer of loam soil, secured in place using wooden pegs. Soft capping acts as a natural thermal blanket, reducing the effects of frost damage. Rainwater caught in the soft capping will later evaporate back into the atmosphere, rather than washing down the walls and being absorbed into the masonry which would make it even more vulnerable to damage in freezing conditions.

Bakers installed a new LED lighting system to highlight the castle’s prominent position on the historic town skyline at night. Bakers also carried out groundworks to enable visitors to explore within the castle walls.