The Baptistery of St John is one of the most evocative and symbolic buildings of the city of Pistoia. The restoration project principally involved consolidating and cleaning the stone facing of the facades. Three factors made this task particularly difficult: the architectural typology, the polychromy of the external stone facings and the complexity of the deterioration process (micro-structural, material, biological, and sedimentary). The component parts of the stone base, the facades of the octagon, the lantern and the roofing were analytically surveyed. The deterioration process was analysed and quantified, petrographic and chemical analyses were performed on samples as was metallographic research where necessary. Advanced technologies such as the cleaning stone surfaces of statues and facades using lasers were deployed.

PROJECT DETAILS
Locality: Pistoia

Client: Ente Cassa di Risparmio di Pistoia e Pescia – Chapter of Pistoia Cathedral

Brief: final design project, working drawings and project management

Designed: 1998

Realized: 1999-2000

Collaborators: Giulia Cellie, Federico Gurrieri, Francesco Gurrieri, Studio Arch. Roberto Fedi (safety coordinator), Studio Arch. Alessandro Supressa, Studio Lombardini Engineering (consulenza progetto iluminotecnico)

Building Firm: M.I.D.A Pty Ltd from Pistoia

Photographic credits: A. Andreini and C. Chiavacci