Repairs to Torteval Church
October 4, 2017 /
Churches are always a privilege for Architects and Surveyors to work on. They are normally landmark buildings, often historic and hold such important community value. Torteval parish Church is no exception and the real conundrum with this building was how to tackle the leaking spire.
This has occurred because of a number of reasons; the Church’s extremely exposed location, the inappropriate use of cement pointing and plaster, as well as condensation.
The high moisture level within the walls has been causing damage to painted interior surfaces and plaster in the lower part of the tower, corrosion to many steel components in the building, accelerated decay to the cantilevered limestone steps (one of which has collapsed), as well as generally high dampness levels, which will result in long term decay to the bells and their timber frame supports.
As the moisture escapes through the wall surfaces it has left salts and evidence of ‘lime bleeding’ on the walls, both on the exterior and interior surfaces with substantial voids therefore undoubtedly present within the core of the granite, lime and masonry walling.
The internal surfaces of the tower and spire were initially coated with lime plaster, and exterior pointing defects temporarily plugged with lime mortar. The tower and spire were then injected with grout (by Geomarine Ltd.). This process was carried out by drilling holes externally in the mortar joints to a suitable depth (approx. 900mm into the 1200mm thick walls), then pumping a lime-based mortar into the walls. This was started at ground level and progressed up the tower and spire. The purpose of this exercise was to fill the voids in the wall, to assist in reducing direct water penetration via the mortar joints, whilst also consolidating the wall structure. This has to be carried out relatively slowly to allow the lime to set before moving upwards.
The external surfaces of the tower and spire are now being re-pointed (Stoneworks Ltd., Main Contractor) with a breathable lime mortar allowing the structure to control moisture, before being coated with a colourless water repellent, to assist weathering whilst the lime cures over the next 12 months or so.
The internal cement plaster to the base of the tower was then removed to speed up the process of drying out the structure. After 12 months this will be reinstated using specialist breathable lime plaster and decoration with specialist vapour permeable paint.
These works will significantly reduce the amount of moisture ingress, preventing further damage to the church, whilst re-stabilising the tower and spire by filling in the voids in the 1.2m thick walls. The appropriate lime mortar pointing will not only allow the structure to breathe properly but also will have a far nicer aesthetic, and combined with the other complimentary works, will rejuvenate this magnificent, landmark building. A drier wall also improves the thermal efficiency of the masonry and will also help to reduce the condensation which can occur at certain times of year.
One of the more interesting elements of this project is the weather vane. This is a high profile piece of the church, visible from a long distance away and very distinctive. It had corroded significantly and we have been working with local tradesmen to restore it to its former glory.
The new weathervane, yet to be installed, will be made of new marine grade stainless steel by Lee Allez and painted black. The copper cockerel and directional fins will be reused after they have been gilded by Smith Signs.
One element that is not sourced locally is the new limestone ball finial. As this is limestone, this is being brought over from a quarry near Swanage, and another specialist business, Lightning Enterprises, are renewing the lightning conductor and tapes
We look forward to the completion of the works and removal of the scaffolding towards the end of this year.