Conservation-restora tion interventions

PERE ROVIRA

Conservation-restoration interventions at the Els Munts site

I VAGUELY REMEMBER THE FIRST TIME I CAME TO ELS MUNTS, TOWARDS THE END OF

1998, with Josep M. Xarrié and Eduard Porta

In the mid-1990s, under the direction of Francesc Tarrats, excavations had resumed in the Roman villa of Els Munts, and the Restoration Centre paid a visit to see and assess the state of conservation of the mural paintings that had emerged during the excavation in the ambulatio rooms. At the entrance of the enclosure, at the time, on the hortus side, there were two caretakers dressed as officials, sitting on two beach chairs, at the foot of a carob tree, guarding the site, which was very unprotected then.

It was not a coincidence or an administrative extravagance, but a reality that proved the importance of the site, and of what had been found there since the last excavations in the 1970s. Everywhere in the villa exuded luxury and comfort. Remains of the stones that had adorned it, from all corners of the Roman Empire, appeared everywhere and testified to the category and importance of this archaeological site. A reality that at the time did not seem like it, but that has become extremely obvious as it has been excavated and restored.

During that first visit, we focused on the domus area to see the new mural paintings discovered in the cryptoportico area and its large mosaic. One of the guidelines that someone had given the archaeologists was that as soon as they discovered the mural paintings, to protect them with a gauze attached with Paraloid® B-72 resin, at that time the “manna” that saved and conserved the heritage. The recommendation was not bad, and in the eyes of a restorer it obeyed a specific temporary fastening criterion, to avoid risk of detachment.

But this misunderstood detail led to protection being applied to the whole pictorial ensemble, regardless of the area, and turned the whole ensemble into a kind of wrapped present. Despite this, the real problem was that these fabrics glued with resin spent too many years on the frescoes, apart from the fact that they were placed without properly cleaning dirt from the surface of the murals.

What was supposed to be a temporary protection was prolonged in time, and created an added problem to the alteration itself of the outdoor frescoes. The mixture of acrylic resin with solid remains deposited on the surface forms a kind of hard and resistant film, difficult to remove as the resin becomes insoluble, and at the same time does not allow the painted walls to breathe naturally.

So, one of the first immediate actions to be taken should have been to remove the fabrics (some of which were already beginning to come off) and especially the resin, which conditioned the stability and aesthetics of the fresco. Its removal, years later, did not lead to the total elimination of Paraloid®, since due to its strong adhesion it still remained all over the surface.

Partial view of the gallery and the lower rooms of the domus, under the roof

All this, in the long run, has meant that some parts are petrified and lifting, due to the barrier effect that the interior-exterior moisture transmission has combined with the presence of salts. This issue entailed restoration on several occasions, to prevent them from further degrading. Nevertheless, the salts contained in the walls have inevitably continued to come out. One of the most recent studies we have carried out at the CRBMC has been to assess the behaviour of the salts and their removal, as well as the cleaning of resin residues using the Wolbers gel methodology, a topic already covered in another article.

One of the first actions for the conservation of the site, and probably the most important since excavations were resumed, was placing a temporary roof over the area of the domus, which largely protected its remains. This large preventive action, the first on an open site in Catalonia, kept the highest and most voluminous facings ever found in a site in our country protected from rain damage, and at the same time allowed us to preserve the original walls, mosaic and mural paintings. Obviously, this prevented the uprooting of mosaics and mural paintings, actions that were all too common in past archaeological campaigns.

But what was good temporary protection, in the long run also ended up being a problem, derived from this same temporary situation. The asbestos material which the roof is made of must be removed, by law, although it has occasionally been replaced due to the alterations it has suffered.

The next biggest problem that appeared was that the rain collected by the roof decanted too much water on the side of the cryptoportico, since there were no gutters that carried water away from the rooms, which caused a lot of moisture and salts to emerge, agents which have damaged the mosaic and murals in that area.

In fact, the protective perimeter of the roof is at the edge (without borders) of the domus elements that it aims to preserve, whereas other parts of it are totally outside, like the peristyle and the triclinium, from which mosaics were taken and transferred, which are waiting in the depository to one day return to their rightful place.

The roof’s intention at the time was to protect those more archaeologically important and better preserved parts of the domus, perhaps in the hope of extending the coverage at a later stage. But the years went by and it was not extended. The metal support structure has also aged. Although it is stable, it has gotten rusty. And the multiple cement support bases included within the original walls have also damaged the original walls they are supported on, basically

Part of the mosaics extracted from the ambulacrum and deposited in the storerooms of the MNAT

Overview of the roof that covers an important part of the domus

The support areas of the old roof structure have also conditioned the conservation of the place it occupies, which will not happen with the new roof, as the supports will be far away from the house

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because they were made of mud. Leaks from the wear and tear have also appeared and need to be repaired quickly to avoid puddles of water and the subsequent alterations they entail.

The complex hydrological system that the whole villa presents makes the conserving its elements more difficult, although the slope where it is located faces the sea. When the villa was active, water movements were probably controlled and properly directed, which meant that there were no logical problems of a corroded site.

In fact, many of the original pipes and drains of the domus could continue to operate if their course was not blocked by occlusions and earthworks, which would facilitate this necessary drainage. The very constructive morphology of the domus, integrated into the hill and taking advantage of its slope, causes the water from the upper area to filter inwards and make a logical descent, a problem that the temporary roof cannot solve by itself. In this way, the appearance of sources of water on days of heavy rain ends up also leading to the site’s deterioration, which is very common in archaeological sites.

Given the problems caused by water at the site (water movement and drainage), one of the main objectives of the National Archaeological Museum of Tarragona (MNAT) was to plan to cover the entire site with a new roof. The new project was developed by the office of architect Estanislau Roca (RC Arquitectura i Projecte Urbà, SCP), and was done at a conservation level following the guidelines given by the CRBMC, in order to completely preserve the elements contained in the site.

The initial project was really spectacular, and allowed to visit the entire site along a high walkway, while protecting the whole area. The initial idea was also for the roof to be modular and that it could be consecutively extended over each area, until the whole site was covered. This would have made it possible to diversify the cost of the whole ensemble and distribute it over several years, depending on the possibilities. But we were faced with the economic reality of the Department of Culture, so we had to change the initial intention of the MNAT and the CRBMC to cover the entire site, and only partially cover the area of the domus. This major action is planned for the near future, and will replace the temporary roof with a new larger (but not full) roof, with wide enough margins to better protect, at least, the paintings and the mosaic. This roof will also reinforce the structures outside the scope of the domus and channel the water collected by the roof, which will be directed mainly towards the original drains already present at the domus. The new project, despite being more modest and without modulations, is still a good project, in order to protect the remains.

However, despite the Museum’s huge efforts, so far only the water from the old roof has been channelled, already helping to improve general conservation. This harsh reality contrasts with the rest of Spain and other countries that cover many of their sites, at least the most important ones.

Something we were pioneers at and are now the last in line. The Department of Culture prefers to invest the little money it has for archaeological sites in building fake walls and theatrical decorations, for the enjoyment and entertainment of tourists accustomed to Netflix series, rather than carry out serious site preservation projects. Mental recreations will not make us knowledgeable in the eyes of science and history; nor richer. Of course, tourists will have the ideal theme park to be satisfied with their visit. For now, we are forced to put another “plaster” over the site’s suffering: a partial roof over the domus of the most important residential villa in the Iberian Peninsula. This is better than nothing. But it’s half a job.

At all sites, the maintenance and conservation-restoration costs, with the continuous and irreparable loss and damage to elements, and with most mosaics and mural paintings forgotten in the depositories because they can not return to their place, far exceed the cost involved in building a roof. Never put off until tomorrow what you can do today. Dum Roma deliberat, Saguntum perit.

The latest studies commissioned in 2020 by the MNAT to Flumen, SL for the improvement of the site’s surface drainage give a very clear diagnosis of the hydrological and hydraulic behaviour, both of run-offs and sediment transport and deposition, as well as action proposals to reduce the effect of flooding and subsequent erosion. Despite knowing the reality around us, the best recommendation pointed out by the study for the preservation of the site is its complete coverage. Fancy that! It also says temporary covers can be chosen for areas that do not have natural drainage, such as the area of the domus, the Mithraeum, the deposit of the hortus and some rooms in the southern baths. It also points out the need to build small moats and slope changes, in order to channel surface water safely and prevent it from depositing on visible elements. Carrying out these actions will be essential for the conservation of the site, and thus also start conservation-restoration actions with long-term stability guarantees.

Map of the areas most at risk of alteration. Illustration: CRBMC

Going back to this article’s opening line, one of the important things we also saw that day was the fresco decorative mural, which presided over the fountain that was located in one of the rooms facing the ambulatio. The construction of a cistern and a fountain was an important enough action for it to be erected in honour of the god Oceanus, and to include the names of the factorum of this construction: Caius Valerius Avitus and Faustina, the lords of the house.

The discovery of such an exceptional document conditioned a series of assessments on its preservation, and it was decided that it would be best to tear the front down and move it inside, a decision we probably wound not make today. The intervention involved detaching this mural, the first major action by the CRBMC on-site. That detachment was very laborious, as it was done vertically, and took advantage of the section of the wall above. The CRBMC transported the detached mural to a stationary movable support, so that it could be seen inside the Els Munts Interpretation Centre.

In the area of the domus cryptoportico, the intervention on the long tile mosaic, which is the only one in the villa that is still in its original place, is particularly noteworthy. This spectacular mosaic underwent cleaning and consolidation, so that it does not degrade further, especially regarding points lifting with tile loss, areas where water collects (derived from rainwater penetrating inside the residential area) and clay tiles that were disintegrating. The restorations were carried out over several years by various specialized professionals, under the supervision of the CRBMC. Currently, despite the needs, no new maintenance actions will be performed until the new roof is installed. Unfortunately, the rest of the mosaics in the villa were torn down and placed on small panels supported with cement,

Design of what the new roof in the first project would have been, but which could not be carried out due to lack of financial resources. Design: RC Arquitectura i Projecte Urbà, SCP

The quality of the mural paintings that adorned the rooms is difficult to preserve given the presence of moisture as was traditionally done, stored in the depository. The intention is that one day, when there is cover, they can be returned to their original spaces, in order to give them meaning and, above all, the visibility that they currently lack.

CRBMC’s line of action on the site began with the Oceanus mural painting and the cryptoportico mosaic, followed by various mural painting restorations, focusing mainly on the residential house and the entrance gallery to the baths (ambulatio). All these actions have served to preserve these pictorial remains, essential to see the site’s decoration.

As we will be see in the various articles in this monograph, the interventions always end up colliding with the humidity problems and environmental conditions, and especially with salts naturally present in the site. The importance of consolidating all the facings with mural paintings over the years is particularly noteworthy.

The last interventions have focused on studying the alterations suffered by the mural paintings of the domus, while maintenance work has been done, with the removal of the new emerging soluble salts and microbiota, and to continue consolidating the affected mortars and paintings. A job that has had particular incidence this past year, due to the amount of rain that has fallen.

One of the most spectacular finds made during the excavations in the domus has been

Mural painting of Oceanus, after restoration Topographic map of the observed run-offs (red arrows) and main incidence points (numbered triangles). (Flumen, SL. Source: ICAC)

Location of the cistern and the fountain where Oceanus was located, which the hosts of the house had buvilt. Photo: Pere Rovira

the coffered ceiling with fresco polychrome, which was located in one of the secondary rooms (no. 4700), a piece that, due to its characteristics, is unique in the empire at this time. Its multiple fragments were recovered, and its recomposition began in 2006. We are currently working on it, so that by 2022 it can be exhibited fully restored. An artistic marvel of great technical complexity in terms of its restoration.

The southern baths represent a very important part of the site, with many preserved spaces, where work has also been done to consolidate the remains of mural paintings and mortars in the pools and accesses, as well as to partially recover the demolished parts of the hot water pool floor (caldarium). As in the other rooms and spaces of the site, only part of it has been done, and it is necessary to continue working on its restoration and maintenance.

Recently, efforts have also focused on the Mithraeum, the worship space of the villa, of a quality comparable to that of the baths of Caracal·la, in Rome. It is a very important and quite damaged room, which is not currently included in the tour, as it is still under restoration. This area, built as an adjoining wing, perpendicular to the ambulatio, requires continuous interventions to consolidate the mortars and restore the mural paintings on the preserved facings. Also, as in other areas on-site, the perimeter land needs consolidating and adequate draining so that the water does not damage it further.

As in the whole site, after an excavation, the emergence of new built structures causes their continuous wear, as they have been stripped of protection. It is essential to arrange rainwater movement, in order to prevent landslides, especially severe in the Mithraeum. And they are the necessary preliminary steps before the final restoration of mortars and mural paintings. For the time being, the areas with mortars and mural paintings have been temporarily consolidated, awaiting a global restoration of all this space, which must include the relocation of ashlars and fallen elements, and the preparation of available ground, if that is possible.

Other unique site elements, such as tanks and cisterns, have also been the subject of intervention, in this case the large rectangular cistern called “Castel” and the tank called “La Tartana”. The cisterns have been essential elements for the life of the villa and its crops, and its conservation helps explain this, as well as showing the

The gallery mosaic after the restoration treatment

Romans’ excellent construction skills. Cistern restoration focuses mainly on replacing the joint mortars and consolidating the slabs of lime mortar that covered their walls, apart from removing the upper plants and carrying out the necessary biocidal treatments so that they do not degrade.

The architectural actions within the museographic field that have been made in the visitor’s tour have always had two very clear aims. On the one hand, to mark a more or less safe line of passage, with firm enough ground suitable for walking, in order to avoid margin exits that could damage the excavations and the visitors themselves. On the other hand, to point out the different areas and give a tidy overview of the site and all its spaces.

It is important that these actions do not damage the original elements or structures, nor that they condition the archaeological aesthetics, which is why we have worked together with the architect and the archaeologist. The inclusion of new elements such as wooden parterres and protective railings help to preserve the ensemble and facilitate the passage of visitors. In fact, it is important to ensure that the new elements brought to the site aid its conservation, especially adapting accesses that must facilitate the circulation of rainwater. The last action of this type, a project drafted by the architect Miquel Orellana, focused mainly on the area of the deambulatio and the baths. Despite some liberties taken when reintegrating some architectural elements, the route through the site is logical and understandable, and includes almost the entire uncovered space.

The site’s greatest enemy are all those degrading agents of biological origin that coexist within it, so it is necessary to apply good preventive conservation, which can never be left out. As a whole, one of the main objectives for the site’s maintenance (like that of all outdoor archaeological sites) is to have a good annual preventive and maintenance programme, to minimize the impact of vegetation and microbiota on all uncovered structures and elements. Although minimizing biological elements in an outdoor environment is a pipe-dream, it is necessary to be insistent and constant when treating biota, and to keep it from exceeding the point in which its proliferation can condition the conservation of the ensemble, always respecting the environment.

The interventions described in this monograph are a short summary of what has been done and what must be done in the coming years. No matter how much is done, a site of these characteristics will always have pending actions, but we want the ones we perform to not condition the future. Carpent tua poma nepotes.

Beginning of the assembly of the ceiling fragments recovered in the excavation of room no. 4700. Photo: Misi Bruned

Appearance of the cold water pool (frigidarium), outdoors, before the intervention

General appearance of the Mithraeum before the intervention

Hot water pool (caldarium) with a partial reconstruction of the heating system

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The walking area in the direction of the baths, with the new pavement that facilitates access

Large cistern, called “Castel”, with biological colonization derived from its location outdoors. Photo: Sílvia Llobet

Increase in higher plants in the Mithraeum area. Biota growth control requires continuous maintenance of the site. Photo: Sílvia Llobet

DETAILS

GENERIC CLASSIFICATION: archaeological and palaeontological material | OBJECT: site | MATERIAL/TECHNIQUE: mural painting | DATE/ERA: Roman, from the 1st century BC to the 7th century AD | LOCATION: National Archaeology Museum of Tarragona. Roman villa of Els Munts, Altafulla (Tarragonès) | CRBMC REGISTRY NO.: 14145 | CATALOGUING: Archaeological ensemble of Tàrraco declared a UNESCO Human Heritage Site. 2000. Cataloguing BCIN 2044-ZA