THE’Italy It is a country that boasts a huge number of historic buildings that, to remain available to everyone, allowing anyone to enjoy their beauty and value, must be regularly restored. Here then we explain how historic buildings are restored, what are the phases, And what is done, concretely with techniques and materials, to preserve and enhance the beauty of the building having historical and artistic value in our country.
The phases of the restoration activities
Let’s see how, and according to what phases, the restoration process of an ancient building is divided.
Preliminary investigation and diagnostics
Before any intervention, it is crucial to understand the state of health of the building. In this phase it is of fundamental importance to understand exactly what the building is needed to be restored, what are the problems that afflict it and what the targeted interventions. In this phase, the first place, the architectural and engineering study of the building is carried out, settles when it was built, those who designed it, what changes has undergone over time (additions, demolitions, function changes), significant events (fires, earthquakes, wars). In order to obtain the necessary information, the technicians are looking for documents in historical archives (of state, municipal, private), libraries, ancient maps, vintage photographs, testaments, notary acts. Sometimes they also consult oral testimonies, if there are available.
Then one is performed material analysis with which the building was built. In fact, it is essential to know the material with which the building was made, as each material has its own characteristic response to stresses such as the loads, but also to the degradation due to external factors, which inevitably “attacks” the building. They then take place small champions not invasive from the building, which They are then analyzed in the laboratory. Chemical techniques are used (e.g. spectroscopy, chromatography) to understand the composition and physical techniques (e.g. water absorption test, microscopy) to study the structure and behavior.
Then we proceed to one Estimation and identification of the causes of degradation. Among the primary causes of degradation of historic buildings there is the time, but also humidity. The capillary rise of water from the ground, infiltrations from defective roofs or gutters, condensation, represent an important danger for historic and historical value buildings. Other causes of degradation may be chemical agents present in the air (e.g. sulfur dioxide, nitrogen oxides) that react with construction materials (stones, mortars), causing erosion, black crusts, chemical degradation.
The ground movement It is a further cause of degradation of buildings. In fact, telluric movements that cause cracks, collapses or structural weakening. Even differential settlements of the soil can lead to serious damage.
The design of the intervention
Once the problem is understood, we move on to design phase. In the choice of intervention and the project, a rule applies which, to date, is considered golden in the world of restoration: that of the slightest intervention.
In fact, when restoring a building, it is generally preferred consolidate Instead of reconstructing, starting from scratch. Only the bewitched parts, aging and small imperfections are restored are part of the history of the building and should not be deleted, unless they are the cause of degradation. The traces of the past, such as layers of plaster or signs of changes, are precious and must be preserved as part of its identity.
Another cardinal principle is the reversibility. This means that the materials and techniques used in the restoration should be conceived so that they can be removed in the future, without causing damage to the original.
The restoration site
This is the operational phase. Restoration interventions can be divided into the following macro-categories. First of all, we have structural consolidation interventions, in which we intervene in order to prevent any collapse of the structure.
The interventions in this sense consist of:
- Fluid mortar injections: to fill empty and cracks in the walls, improving its cohesion and load -bearing capacity. Malte based on natural hydraulic lime are used, compatible with ancient walls;
- Sew and dark: traditional technique that provides for the selective removal of degraded wall elements and their replacement with new elements (bricks or stones) of similar shapes and materials, linked with compatible mortars;
- Circle and tie rods: to counteract thrusts and walls of walls or times. Appropriately sized steel tie rods are used, sometimes pre-established, or circles to contain horizontal thrusts. The visual impact is reduced to a minimum or reversible made;
- Consolidation of floors and roofs: often we intervene by strengthening the existing wooden structures with wooden prosthesis or with the addition of new members who work in synergy with the original ones. Composite materials can also be used (carbon fibers, glass fibers) in a targeted and reversible way.
Source of Stanisław Skowron – proper work, public domain.
The subsequent phases of intervention include the restoration of the surfaces, such as facades and also frescoes inside the building itself.
Post-root maintenance and maintenance:
The work does not end with the completion of the intervention. Once you have finished restoring a building, it is necessary to proceed with a whole series of new assessments, in order to evaluate whether the restoration intervention has given the desired fruits. It then starts with one General verification of the effectiveness of the intervention. It is assessed, for example, if the cracks that proceeded to fill with the mortars are not presenting cracks or signs of early enhancement. It is assessed if the rising humidity has fallen under an admitted percentage value, previously established.
At this stage, then, the appearance of further new problems which will certainly require intervention in the future. First signs of cracks, humidity stains, excessive deformations require they are promptly recognized in order to proceed with an effective evaluation. At the structural level, the structural elements come then observed and analyzed In order to evaluate whether the restoration intervention guarantees a minimum level of accepted risk of drawing on operating limit states.
Among the most used technologies, for example, IoT movement sensors are able to read tensions, deformations, cracks in the structural elements, restoring data constantly. These data are then processed by technologies that also make use of the support of the IA, and are able to indicate to the technician which parts of the building are needed of a restoration-restoration and structural safety intervention.
Challenges and critical issues of the restoration
It is necessary to proceed with targeted restoration activities since, through the restoration works, the historical and cultural value of the building itself is preserved. This involves the maintenance of a real dialogue between present and past, as each building, from the palace in the center of a large city of art, to a simple country house, tells us a story, and safeguarding every building that has a certain historical-cultural value means enhancing our culture, our identity as a people and national belonging.
Each restoration activity contains a significant economic and social value. A recovered historic building is not only a monument to be admired, but a potential development engine. It can become a museum that attracts visitors, a cultural center that revitalizes a neighborhood, an office or home that offers new spaces of life and work, or even a commercial activity that generates induced.
Restoring a historic building represents an interesting, very useful and precious activity but which, however, has many critical issues. A first criticality is certainly represented by the problem of balance between conservation and functionality. This means, for the technicians called to carry out the restoration activities, the need to find a meeting point between the conservation of what is ancient and dating back over time, and what, instead, is linked to modernity and often connected with technical needs.
This also involves a second problem, that relating to ethical and methodological choices to proceed with the restoration. The crucial point is FIn what extent can you go to restore? What is the limit between conservative restoration and historical false? Then there is the problem of costs of restoration activities. Carrying out restoration activities is an activity with great added value, and therefore need for large sums of money. Very often, the lack of funds involves the need to reach the compromise between the costs, in fact, and the activities you choose to perform. This can, in some cases, lead to partial results.
