Restoration and Conservation of the Gates of Altopascio
Year: 2018-2019
Location: Altopascio (LU)
The gates of the fortified village of Altopascio are a central element of the medieval defensive system. Built starting in the 13th century, they were part of a stone curtain wall, completed with towers, arrow slits, and fortified entrances. Over time, these structures have undergone modifications but continue to bear witness to the historical and architectural past of the village.
In 1628, the castle walls included four main gates:
• Porta Pesciatina (now Porta dei Mariani), which connected Altopascio with Pescia.
• Porta Fiorentina (now Porta dei Vettori), the access route towards Florence.
• Porta del Padule, facing the marshy areas.
• Porta del Giardino, providing access to green spaces.
The gates undergoing intervention are Porta dei Vettori and Porta dei Mariani.
The gates showed widespread deterioration:
• Environmental degradation: Smog, acid rain, and temperature fluctuations had accelerated the deterioration of surfaces.
• Biodegradation: Growth of mosses, lichens, and bird guano.
• Compromised materials: Disintegration of mortar and bricks, loss of cohesion of stone blocks.
• Insufficient maintenance: Inadequate previous interventions and lack of regular monitoring.
Among the gates, Porta dei Vettori presented a higher structural risk, with significant subsidence and detachment of masonry elements.
PORTA DEI VETTORI
• Structural scaffolding: Installation of a support structure designed to stabilize the arch and the brick infill.
• Site protection: Mounting of protective sheets and covers to prevent the risk of falling materials.
PORTA DEI MARIANI
• Protective scaffolding: Mixed systems to ensure safety during restoration.
• Preliminary cleaning: Manual removal of soil, moss, and surface debris.
• Specific treatments: Application of biocides and desalination agents to eliminate biodeteriogens and harmful salts.
Materials and Techniques Used
• Consolidants based on nanosilica (NanoSil NS 30).
• Mortars compatible with historic masonry, made from natural hydraulic lime (NHL 3.5).
• Specific biocides for surface cleaning.
OPERATIONAL PHASES
• Pre-consolidation: Stabilization of deteriorated stone surfaces.
• Cleaning:
– Washing with deionized water.
– Manual brushing to remove dirt and biodeteriogens.
• Structural consolidation:
– Repair of missing masonry portions using the scuci-cuci technique.
– Injection of natural hydraulic lime mortars to improve the cohesion of stone blocks.
• Repointing and restoration:
– Filling joints with compatible mortars.
– Reconstruction of missing surfaces with similar stone materials.
• Finishing and protection:
– Application of a siloxane-based water-repellent protective coating to prevent future infiltrations.
The gates of Altopascio are an architectural and historical treasure of great value. The restoration and safety interventions have made it possible to preserve these structures while ensuring their integrity and usability for both citizens and visitors.
Through the use of advanced techniques and compatible materials, this project represents a virtuous example of cultural heritage conservation, ensuring a long lifespan for these testimonies of the past.
