Rainfall and ivy damaging medieval churches

THE spread of ivy and increasing rainfall rates in recent years is causing immense structural damage to the county’s medieval churches, according to a new survey.

A Medieval Church Survey for County Clare, which is funded jointly by the Heritage Council and Clare County Council, is the most extensive study of its kind since the letters of O’Donovan and Curry in 1839.
The survey found that a third of the 170 churches surveyed have disappeared in the intervening 172-year period, while a third are in a dilapidated condition and are at serious risk of disappearing. Approximately 55 churches were found to be in good structural condition, mainly due to the presence of intact or partially intact roofs.
Surveyor Simon Large, who was contracted by Clare County Council to carry out the comprehensive study, said an increase in rainfall in recent years has accelerated the washing out of lime mortar, while ivy has caused considerable structural damage to many of the churches studied during 2011.
“The issue of ivy and its encroachment is the most worrying aspect associated with the ruination of Clare’s medieval churches,” he explained. “Ivy obscures the building, covering emerging structural flaws and details of the church itself. It is destructive, forcing its root system into the fabric of the structure, replacing the mortar with its root and vine system. As ivy grows and becomes established, it forces apart the bonding of the structure,” he added.
“Because of its invasive nature, pulling down established ivy is actively discouraged, as removing established ivy can pull down large sections of upstanding walls. Ivy growth needs to be inhibited, and kept inhibited by regular and frequent tight trimming. The extent of the invasive nature of the ivy needs to be established, along with the condition of the building fabric in relation to the ivy and appropriate responses agreed. If this is done, a plan of eradication might be possible,” he said commenting on possible ways of containing ivy growth.
Meanwhile, Mr Large noted measures could also be taken to reduce the effect of rainfall on medieval church structures.
“It is widely accepted that rainfall will increase in the years ahead. This will accelerate the washing out of lime mortar, thereby weakening the church fabric. To counteract this risk, this survey proposes the capping of exposed church walls, where appropriate. This is only appropriate where the wall or walls are vertical and survive in a good and stable condition,” he cautioned.
Commenting on the survey, Congella McGuire, Clare Heritage officer said the survey has given Clare County Council a comprehensive picture of the threat of both ivy growth and erosion to the many church ruins in graveyards throughout the county.
“It is a very valuable and informative resource for local communities, who wish to consider projects to conserve these buildings. Conservation works to buildings of this type can be a difficult and complicated process and requires permission from both Clare County Council and the National Monument Service. Local communities wishing to carry out works to safeguard these building should, in the first instance, contact the Clare County Council Architectural Conservation officer, Dick Cronin, for advice and assistance,” she explained.
“The survey report is available in hard copy through the county’s network of local libraries,” Ms. McGuire added.