Wetter Climate Damaging Mediaeval Churches
The spread of ivy and increasing rainfall rates in recent years is causing immense structural damage to Ireland’s mediaeval churches, according to a new survey.
The survey found that a third of the 170 churches surveyed have disappeared in the intervening 173-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, due mainly to ongoing maintenance and in some cases 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 that an increase in rainfall in recent years has accelerated the washing out of lime mortar, while ivy also has caused considerable structural damage to many of the churches studied.
“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.
Commenting on possible ways of containing the ivy growth, Mr. Large said: “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.”
Meanwhile, Mr. Large noted that measures could also be taken to reduce the effect of rainfall on mediaeval 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.”
Commenting on the survey, Congella McGuire, Clare Heritage Officer stated: “This 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 Clare. It is a very valuable and informative resource for Local Communities who wish to consider projects to conserve these buildings".
"Conservation works to building on this type can be a difficult and complicated process and requires permissions 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".
"The survey report are available in hard copy through the County’s network of local libraries", concluded Ms. McGuire.
The survey was restricted to 170 churches as identified on the Record of Monuments and Places, as produced by the National Monument Service.
The finished survey is in two parts. The Access Data Base, which is a searchable document. There are 21 different searchable categories; such as graveyards, round towers, holy wells, location, ease of access and so forth. The churches are also searchable by name, townland and monument number. The search base is linked to the detailed site visit of each church, which is divided into general description, church, graveyard and history. The second part is a Photographic Record, which contains location maps, images of the church, and important related structures; also the graveyard and any architectural fragments identified.
Other Survey Findings:
The condition of the churches surveyed varied greatly from total ruination where nothing survived, to very intact churches with just the roof missing.
Roofed Churches: There were eight churches which retained a complete or partial roof. The roofed churches are St Catherin’s, Lakyle, St. Mochulla’s, (partial), Friar Island's Oratory (partial), St Flannan's Oratory, Kilnasoolagh, Sixmilebridge, and Oatfield.
Church Fabric: There was a change of building material as location changed. In the South West and the West, shale and flagstone became the dominant building material, illustrating how builders sourced local materials. Shale / flagstone churches appear inherently more stable even when the lime mortar is washed out by rainfall. This is, in part, because of the original construction methods used. The shale / flags churches are roughly “coursed”, which facilitates the inserting of crossing tie-stones. In East and South Clare, dressed rubble limestone is the dominant building material. The walls of these churches are usually built with an internal and external facing of dressed rubble stone, with a rubble/mortar infill, and are the most vulnerable to rainfall damage.
Key Survey Recommendation:
Where churches are in an advanced state of collapse or survive only as a wall or even scattered stones a detailed Archaeological record should be completed. (In some cases this may require limited excavation, under license from the National Monument Service).