Monday, 5 November 2018

Masonry Works at Coldingham Priory

The earliest building Smith & Garratt has worked on to date is Coldingham Priory, established in 635AD.

Substantially damaged by fire in 683, it was re-built, but was destroyed by Vikings in 870.  In 1098 King Edgar required it to be re-established on its current footprint and works were completed in 1100.  It grew in extent and importance under the Benedictines of Durham but was destroyed by King John in 1216.  The more imposing replacement was torched in 1430 by its owner, William Drax, to cover his theft of money sent from James I of Scotland to Henry VI of England, was repaired and put under the control of Dunfermline Abbey.  It was damaged by English invasions in 1537 and 1547.  In 1650 Cromwell found it occupied by Calvinists opposed to him after the beheading of Charles I (thought of as Scottish, because he was born at Dunfermline); Cromwell laid siege for two days and then destroyed the Priory with cannon, leaving only two of the Choir walls standing.  In 1622 two further walls and a roof were added to re-make a church, and these were pulled down and rebuilt in the 1850s to form the building we see today.

170 years on, the masonry requires attention.  Somehow, some of the stones have got laid the wrong way – what we call ‘face-bedded’.  Sandstone laid on its bed is quite resilient, but when face-bedded it is weaker and prone to spalling.  Exacerbated by pointing with cement-based mortars since WW2, the decay is now chronic, with much weathering and fragments becoming detached.

The Church of Scotland asked us to produce a programme of stone repairs, hacking-out and repointing.  The programme had to be produced on a shoestring, so Smith & Garratt’s Architectural Technologist, Taylor Dickinson, decided to create a 3D model using photogrammetry, and to plot the resulting images of elevations to scale – with individual defects highlighted.  This produced full, flat, scaled, colour images, showing 568 individual stone repairs, 73 new stones and 937 square metres of pointing, for a tender process.  Taylor thus precisely identified and specified 1,578 individual repairs using an ordinary camera and some computer know-how … for 95 pence each.  At Smith & Garratt we like an innovative answer to a practical problem.