Consolidation and Restoration Work on the Church of the Immaculate Conception in Ischia
The Sanctuary of the Immaculate Conception is located in the municipality of Casamicciola – Ischia, along Via Castanito. The building stands on the hill of Sentinella, overlooking the Sant’Antonio descent, and has a rectangular layout with a single nave. The building was rebuilt and reopened for worship in 1885 with the title of “Church of Mary Immaculate.”
Aerial view of the church
In the early hours of November 26, 2022, heavy rains hit the island of Ischia, causing numerous landslides on the northern slope of Mount Epomeo. The mudslides and debris flows caused 12 deaths, severe damage to buildings, infrastructure, and economic activities, and reached the sea, partially burying the port. The volume of material displaced was tens of thousands of cubic meters, similar to that of the events of 2006 and 2009. The rainfall was exceptional, with intensities of up to 168 mm in 12 hours and return periods exceeding 100 years.
For the municipality of Casamicciola Terme, the hydrogeological hazard review indicates that the church falls within ‘Zone C’, where the risk conditions have not changed significantly compared to the period prior to the event. Any situations of instability must be verified locally. Standard civil protection measures apply in this area: no specific action in the absence of an alert, while in the event of a yellow or orange alert, normal self-protection measures are recommended (do not use basements, limit travel, etc.), in accordance with the Hydrogeological Risk Plan (PAI).
Excerpt from the table reviewing the hazard level of the municipality of Casamicciola Terme in relation to the effects of the landslide and flood events of November 26, 2022 – Mapping with aggregates
Description of the Church
The sanctuary consists of three adjacent buildings: the church, the bell tower, and the sacristy. The church, with a single nave approximately 15 meters long and 6 meters wide, has two small side chapels that form a Latin cross plan. It has a pitched roof with a wooden structure and a decorated coffered ceiling, while the semicircular apse and choir are covered by a concrete ceiling.
Next to the church, on Via Castaneto, is the bell tower, approximately 14.6 meters high, built of masonry and reinforced concrete, with a metal reinforcement structure at the top. The inner courtyard houses the service rooms, the sacristy, and the rectory on the upper floor, connected by an external spiral staircase that also provides access to the choir loft above the church entrance.
The building features different construction techniques due to successive phases of expansion: the church combines a ‘barrack-style’ structure (wooden frame and plaster on wattle and daub) with load-bearing tuff masonry in the apse; the bell tower combines masonry and reinforced concrete core; the sacristy and other rooms are masonry with brick and concrete floors. The roofs have undergone various renovations, with the replacement of trusses and the introduction of concrete elements and insulating materials.
From a historical point of view, the church was built around 1703, as attested by documents from the Curia of Ischia, and rebuilt after the earthquake of 1883. It reopened for worship in 1885 to house a wooden statue of the Immaculate Conception, recovered from the rubble, and is also dedicated to Saint Anthony of Padua. The bell tower, completed in 1923, houses bells and a clock made by the Curci company.
The architecture is sober: the interior and exterior facades are simple, without major decorations, except for a few plaster friezes with Marian themes. The ceiling of the nave is decorated with wooden and plaster motifs, while the ceiling of the apse features a relief depicting the Holy Spirit.
Plants of the Sanctuary – Internal subdivision diagram
Interior view of the church and decorative detail
Cruise of the Nave: painting depicting the Immaculate Conception
Main facade
Inside the church there are four marble altars: two in the apse and two at the ends of the transept. In particular, the altar in the apse has a niche decorated with marble above the monstrance, in which the wooden statue of the Immaculate Virgin Mary is placed.
View of the altar and detail Wooden statue of the Immaculate Conception
Two other marble altars, as mentioned, complete the assembly. These are located at the eastern and western ends of the transept and feature two paintings, as shown below.
Paintings placed on the two side altars
The choir loft is located at the entrance, on a wooden floor approximately 3.70 meters above the ground floor. As mentioned above, this area can be reached via a metal spiral staircase located in the courtyard and houses a pipe organ.
Finally, in the bell tower, located to the right of the main façade of the church, the bronze bells and the clock made by the Curci company in 1923 are located at the top.
Criteria underlying the interventions
The work on the Sanctuary follows the Guidelines for the reduction of seismic risk to cultural heritage, in accordance with the Technical Standards for Construction and the guidelines for post-earthquake reconstruction in Ischia (2023). The work must prioritize conservation, local repairs, and the least possible intervention, in accordance with the principles of the Venice Charter (1964).
Historic buildings have different construction types and transformations, making standard verification procedures difficult. Therefore, seismic safety must be assessed both qualitatively and quantitatively, considering:
– the current situation of the structure and recognized vulnerabilities;
– the safety achievable with interventions compatible with heritage protection;
– the acceptance of a higher level of seismic risk if invasive interventions would compromise conservation.
It is necessary to have a thorough understanding of the structure, its construction history, and the transformations it has undergone, adopting appropriate mechanical models to simulate structural behavior and validating analyses based on existing damage. It is necessary to define the reference seismic safety levels according to the building’s class of use and assess its nominal life, designing improvement measures that are compatible with conservation and guarantee the durability and compatibility of the materials. To support all this, it is essential to use historical knowledge and comparisons with similar buildings to correctly interpret the structural behavior.
Structural interventions
The structural project aimed to increase the load-bearing capacity of the sanctuary’s structural complex by replacing and rebuilding some of the church’s load-bearing elements (nave and apse) and consolidating the bell tower.
Ground floor – Interventions 1, 6, 7, 8, 9, 10, 17, 18, 19
First floor – Interventions 2, 3, 4, 5, 11, 12, 13, 14, 15, 16
3D view – FEM model
3D view – FEM model
Restoration work
Restoration on the coffered ceiling
The church, with a single nave approximately 15.30 meters long and 6.44 meters wide, has two side projections measuring 1.40×6.34 meters located before the transept, giving the building its typical Latin cross plan. The area is covered by a pitched roof with wooden supporting structures, concealed by a false ceiling (“dead ceiling”) located about 7 meters above the floor, composed of coffered panels decorated with wooden friezes and plaster frames. In the crossing there is a painting depicting the Madonna of the Immaculate Conception. The coffered ceiling, dating back to the late 19th century and decorated with gilded wooden panels, has no particular features of note.
The project involved demolishing the false ceiling and pitched roof to build a new attic and roof, both with wooden structures. To proceed, the existing coffered ceiling had to be dismantled; however, due to its state of preservation, it would not be possible to preserve the original elements or guarantee their safe relocation. For this reason, it is planned to preserve only the central portion of the intrados in the crossing with the painting of the Immaculate Madonna, replacing the rest of the coffered ceiling with a new lightweight structure in plasterboard, which will give the nave a new geometric configuration. The intervention is of a replacement nature in the nave (at the vestibule/choir loft) and completely new in the presbytery area.
Ceiling view
Restoration work on the interior decoration
The interior decoration of the church shows widespread cracking, attributable both to the construction system (plaster on wattle and daub) and to recent seismic events. In order to assess the actual state of conservation of the plasterwork, the restoration project initially involves cleaning by means of micro-abrasion and manual scraping of the layers of paint superimposed on the original. A visual inspection revealed that, in recent times, non-breathable synthetic paints have been applied, which are unsuitable for the particular substrate of the plaster and decorative elements. The cleaning also includes the removal of paint from the plaster in the relief parts, such as frames and moldings.
Once the cleaning phase has been completed, the plaster will be restored using the following procedures: cracks will be opened by carefully chipping away the affected areas and then filled with pozzolanic hydraulic lime mortar. The outer layer of the plaster will be consolidated by applying a restorative and homogenizing agent based on lime putty aged for 24 to 36 months, derived from pure calcium carbonate, with selected crystalline carbonate aggregates and vegetable additives, applied in two coats with a steel trowel to a minimum thickness of 3 mm. Subsequently, a mineral paste skim coat, free of synthetic additives, will be applied, and finally, the interior will be painted with natural, breathable mineral paint, based on seasoned lime putty, crystalline carbonate aggregates, vegetable additives, and natural pigments, also free of synthetic components.
View of the interior decoration
Restoration work on the cane structure
The wattle system found along the perimeter of the church serves both a structural function and a supporting function for the internal wattle, onto which the plaster and decorative elements are applied. Visual inspections have revealed that the mat used is thin, with a weave that is not particularly dense, but in general in a fair state of preservation. The restoration of the wattle system will be carried out from the outside, after the demolition of the perimeter infill masonry. Given the characteristics of the reeds, which are thin and not completely joined together, the intervention will be precise and local, mainly dry, without the use of mortar or resins that would increase the load on the structure.
The operations involve removing areas with loose, unstable, or rotting reeds and securing the detached parts by nailing stainless steel nails from the inside out onto the already restored shack structure. For the additions, mats or bundles of reeds of the same type and weave as the originals will be used, bound with nylon to ensure resistance to moisture and insects and to make the intervention more visible. The new mats will be inserted into the gaps, after removing the internal plaster and any portions of friezes, moldings, or decorations, and secured with stainless steel nails.
The external facade of the reedwork will be cleaned manually by dry vacuuming, without the use of solvents or water, and then treated on the outside with linseed oil, which will nourish and protect the system from pests and moisture, while ensuring its breathability.
Interior views with details of the cane work
Standards
[1] Legge 5 novembre 1971 n. 1086 (G. U. 21 dicembre 1971 n. 321) “Norme per la disciplina delle opere di conglomerato cementizio armato, normale e precompresso ed a struttura metallica”;
[2] Legge 2 febbraio 1974 n. 64 (G. U. 21 marzo 1974 n. 76) “Provvedimenti per le costruzioni con particolari prescrizioni per le zone sismiche”;
[3] NTC 2018 – Aggiornamento delle «Norme tecniche per le costruzioni» – D.M. 17 gennaio 2018;
[4] Circolare 21 gennaio 2019, n. 7 C.S.LL.PP. Istruzioni per l’applicazione dell’«Aggiornamento delle “Norme tecniche per le costruzioni”» di cui al decreto ministeriale 17 gennaio 2018;
[5] Circolare n. 26/2010 – Segretariato Generale MiC – Linee Guida per la valutazione e riduzione del rischio sismico del patrimonio culturale allineate alle nuove Norme tecniche per le costruzioni.