The north and south transept ceilings of Peterborough Cathedral are made of wood. The wooden boards have been placed together to form a pleasing diamond pattern, but these were never designed to be seen.
The original medieval transept ceiling was completed between 1155 and 1175 on the request of Abbot William de Waterville. We know very little about the first ceiling other than the evidence of previous wooden beams. But it is thought the ceilings were divided into 12 panels and were likely to have been painted.
The second transept ceiling was created in the early 13th century and crucially before the nave ceiling. It is possible the painters honed their skills on the transepts before attempting the nave ceiling. Some of the wooden boards that remain are from the 13th century, but the paint has been since removed. The paintwork appears to have followed the diamond pattern created by the boards and contained a stylised cross in the centre of the diamond. Restoration work to the ceiling revealed ghost or shadow outlines of some original shapes, from which this design was created.
The ceiling was repaired and redecorated several times, which was left the residue of later painting. Several colours including black, white and brown were easily identified during restoration, but many others would have been used.
A black and white image exists of the north transept ceiling prior to the rebuilding of the central tower. The image clearly shows a diamond pattern and suggests at a bold and bright design.
Reference: Harrison, H, Peterborough Cathedral: The Transept Ceilings, Record of Treatment and Additional Investigations following a fire in the Cathedral on 22 November 2001, (The Perry Lithgow Partnership, 2002)