After some subsidence, one of the supporting walls of the arch of this house in Trowbridge, Wiltshire moved. The reduced support of the arch caused it to drop. Before rebuilding the arch we attached an angle gauge for 8-weeks to ensure all movement had stopped. The centre section of the arch we then removed with the remainder supported by a semi-circle of formwork called a turning piece. The turning piece supports the new arch while it is being built and is removed when the mortar has set. The arch is then self-supporting.