In most lengths of wall, the critical aspect for analysis has been ground/structure interaction and the effect of encroachments from the roots of maturing trees.
The team of engineers have used surveying equipment including its own specialist movement gauges to give direct measurement of relative vertical movements. The gatehouse towers have needed other works. The repairs at Walmgate Bar during 2015 have been outlined above (Walmgate). Additionally, works at Micklegate Bar have been scheduled for 2016 to tackle the problems of eaves-spread.
Durham City medieval walls
The Practice also worked for Historic England on a 30m section of Durham City medieval walls, which was on the ‘At Risk’ Register.