Historic Building workshops

Care and repair of historic masonry structures

Date: 17 March 2017

When: 1000 – 1630

Where: Dunster Castle

Cost:  £120.00 plus VAT (£144.00) to include seminar proceedings, all refreshments, lunch and comprehensive delegate pack

The day’s course will consider in depth three aspects of building conservation.

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• The care and repair of historic stonework
• Understanding historic mortars and the use of lime in conservation
• Historic decorative plasters

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The venue has been carefully chosen as the town and castle represents fine examples of Medieval and later stonework. The buildings of the town are mainly constructed in local stone with slate roofs and some slate hanging on timber frames. The major and very impressive medieval castle dominates the town and display masonry of many periods and centuries of repair including 20th century work. In the 17^th century the castle was refurbished to turn it into a more comfortable country house. In 1868 the architect Anthony Salvin was commissioned to “refortify” the building to the Victorian ideal of what a great Medieval castle should be, but with contemporary home comforts The interior of the castle reflects changing ideas of decoration and comfort with fine examples of decorative plaster ranging through the 17^th and 19^th centuries.  The day will include formal Power Point presentations and first hand observations of some of the buildings in the town and the castle.

The History and Architectural Development of Stone Structures

Stone Buildings are some of our oldest surviving structures in the country and there are many from the medieval and later periods in need of sensitive care and repair. The use of stone was not just confined to the grand buildings and churches but was also used for a variety of ordinary domestic and vernacular buildings. The methods of quarrying, selection and use of stone in the past contributes much to the character and grain of our historic Cities, Towns and Villages.

Care and Repair of Historic Stonework

A basic understanding of historic stone structures will be developed. The identification of causes of failure and the selection of appropriate repair and conservation systems including the selection of replacement stone and methods of fixing will be considered.

Care And Repair of Historic Masonry structures and Selection of Mortars

The first important stage of this process is to identify the sources which have caused the problems of decay to occur; these must be resolved before the stonework can be repaired.  It is also important to understand the nature and function of historic mortars and the dangers of the use of modern cementitious products.  The use of inappropriate mortars can result in the rapid deterioration of historic masonry and long term structural problems. The problems of water movement, salts, frost and the cleaning of stone will be examined.  The methods of re-pointing will also be considered, not only for aesthetic reasons, but to ensure the correct performance and durability of the new joint.

Historic Plasters

Most historic buildings were finished with plain lime plasters internally.  Much of the wall and ceiling plaster has now been replaced with modern gypsum based materials in ordinary domestic buildings.  Original plasters are becoming a rare survival.  The problems of using modern materials on solid wall structures will be considered particularly in relation to damp and the development and movement of salts.  The historic development of decorative plasters will also be examined briefly and its care and repair discussed.  Dunster Castle has fine surviving examples of decorative plaster work which are worth looking at in detail. Dunster flyer can be downloaded here