This Technical Advice Note is part of an on-going series of notes on practical and technical issues which arise in the care and conservation of historic buildings. They provide guidance on the principles involved in a particular issue and are not intended to be used as prescriptive documents or used as specifications on site.

Rather than model specifications, the intention has been to provide an introduction to the subject of corrosion in masonry clad steel framed buildings (excluding housing) constructed in Scotland, England and Wales during the first half of this century. This was a particularly important era marking the departure from traditional load bearing structural masonry designs to now commonly used skeleton frame and curtain wall cladding constructions.

This note draws together existing information on current methodologies used in the repair of corrosion, it also presents information on newer technologies and more appropriate methodologies for the repair of historic buildings. The principles described are generally applicable to all types of cladding materials. This document should assist those involved in the repair of traditional buildings to draw up appropriate specifications and implement appropriate working practices for the particular situations with which they have to deal.

Professional advice and supervision of the type of work described within this document should be sought from material suppliers, Structural and Civil Engineers, no matter how comprehensive the specification and repair strategy. They should have a sound working knowledge of corrosion in masonry clad steel framed buildings and should also be aware of the principles of building conservation.

This note was written by Peter Gibbs of Taywood Engineering Limited, funded by Historic Scotland, Lloyds Bank Plc and The Department of the Environment Transport and the Regions. Acknowledgements go to Roger Sparkes of the Building Design Partnership. Robert Phillips of the National Archives of Scotland who prepared the Impressed Current Cathodic Protection Check List (Annex B) and to Julian Castle of Lloyds Bank, Alan Murphy of Ove Arup and Partners, John Williams and Graham Sanderson of Taywood Engineering Ltd, Brian Clark of the Scottish Executive and Richard Emerson and Mark Watson of Historic Scotland.

INGVAL MAXWELL Director, TCRE