Where archaeological remains are concerned, the Museum has a threefold objective: protection, integrity and accessibility. This means that we work to extend the lifetime of the remains for future generations; preserve their original composition and material aspects; and lastly, with all the appropriate precautions, take steps to allow the public to see the remains up close, to understand their contribution to our knowledge and exploration of history. To properly carry out this essential mission of conserving its collections, the Museum has adopted objectives to ensure excellence in terms of preventive conservation and its emergency response policy.

Conserving collections

To achieve its fundamental mission of conserving its collections, the Museum has set objectives for excellence in terms of preventive conservation and emergency response policies. Pointe-à-Callière applies optimal environmental standards (temperature, relative humidity, lighting, air quality) and museum standards for handling, packing, transporting and displaying objects.

Conserving the in situ remains

The Museum conserves and exhibits thousands of square metres of archaeological remains in situ. They consist mainly of stone or brick masonry, paving stones and stone slabs, wood, and both horizontal and vertical archaeological soils.

Every year, a regular maintenance program is carried out in the remains (removing dust, securing loose stones or bricks, reapplying consolidating products).

With the goal of presenting the remains properly, major conservation work has been planned and carried out since 1992. The soil on which the Museum stands acts as a sponge, drawing the moisture from the water table upward, causing salt deposits to fracture the soil surface and erode the base of the remains. The Museum has developed a very specific conservation program to address this problem.

The conservation approach respects the archaeological and authentic nature of the remains. Since the Museum opened, these principles and methods have been strictly applied. The Museum consults and works closely with conservation experts, including those from the Centre de conservation du Québec and the Canadian Conservation Institute.

In recent years, the most important project has doubtless been the complete restoration of the Ville-Marie cemetery, lasting just over one year and calling on the expertise of Museum staff and outside professionals. Lately restorers have turned their attention to other parts of the Museum, i.e. the wooden pilings of the Royal Insurance Company building.

Work on the cemetery

Pointe-à-Callière is responsible for protecting the oldest traces of the founding of Montréal: the in situ remains of the small Catholic cemetery that Maisonneuve placed outside the walls of Fort Ville-Marie.

These priceless remains are subject to erosion, however, and require very special attention. After many expert analyses, Pointe-à-Callière chose the transfer technique, used mainly in Europe for conserving mosaics and wall paintings and applied successfully at the Museum in the past. Our archaeologists, with the assistance of experts, first consolidated the exposed soil surface with resins, before removing the top layer of soil, section by section, transferring it to a rigid, waterproof backing and then replacing it. This complex and exacting task was carried out in full view of visitors, who had a chance to watch the restoration work in progress.

Preserving remains of the former Royal Insurance Company building

The remains of the Royal Insurance Company building were unearthed during archaeological digs in 1990-1991, and are now displayed at Pointe-à-Callière. The goal of preserving a set of pilings – remains of the former Royal Insurance Company building – meant the Museum first had to study the best methods for meeting the technical challenges linked to conserving and displaying the wooden pilings and the architecture of the former building.

When the Royal Insurance Company building went up, in 1861, a large part of its foundations rested on the older walls of the Berthelet building and the walls along the riverbank adjacent to the building. Where there were no older walls and where the new foundations had to rest on soil beneath the frost line, the builders decided to strengthen the new foundations with wooden pilings driven into the ground. Some of these pilings were 2.5 metres long.

Over the years, consecutive wet and dry cycles and microbial activity in the unstable and porous soil caused the pilings to deteriorate. After a fire in 1947 the tower was deemed unstable, and the Royal Insurance Company building was demolished in 1951. Archaeological digs in the late 1980s unearthed the remains of different periods of occupation on the Pointe à Callière site, including those of the Royal Insurance Company building, a historic witness to the rise and rapid development of Montréal in the 19th century.

Conserving and displaying the pilings
The pilings had been preserved during the excavations in 1990-91, in keeping with the Museum’s conservation mission, but only two of them were displayed in the Museum. They were left in place, wrapped in jute and treated with polyethylene glycol (PEG). This in situ treatment was carried out over a two-year period. Since the pilings were very damp (98% humidity) and had to be displayed without having time to dry out, the challenge was to perform this PEG treatment in situ, to have the PEG replace the water in the wood and thereby keep the wood from warping and splitting. The other pilings were gradually dried out under isolated and controlled conditions in a laboratory.

When the permanent exhibition was renewed in 2003, we decided to give visitors a better understanding of these pilings in the building’s architecture, and of their importance, by displaying a number of pilings in the museum’s remains. After all, they were evidence of the methods used by 19th-century engineers to solve the problem of the unstable ground on the Pointe à Callière site, where the Royal Insurance Company building had stood. Their reinsertion was completed in 2007.

The team began by excavating the part of the ground where the pilings were to be reinserted, where any kind of mechanical excavation was all but impossible. They also began designing customized supports to surround the pilings, of up to 2.5 metres high. The supports developed came with tightening mechanisms that would hold the pilings in place without damaging them. Since they are made from surgical-quality stainless steel, they will not rust, and hence will not interfere with the conservation of the pilings. The supports are not only reversible and versatile, but also discreet, allowing the pilings to be displayed esthetically and in a way that meets both museographic and conservation standards.

All this hard work took three months and required a wide range of expertise – not only on the part of Pointe-à-Callière staff, but also from the Centre de conservation du Québec, the Montréal property and heritage development department, the Quebec Department of Culture, Communications and the Status of Women, and a number of professionals from design, transportation and excavation firms.

Monitoring plan

Since they were displayed in 1992, the remains in the basement of the Éperon building, in the collector sewer and the archaeological crypt have been exposed to environmental conditions and wear much different from before they were unearthed and became part of the Museum. The site is anything but static, as Museum staff members well know. Fluctuations in the water table, variations in underground conditions with the seasons and damage to underground infrastructures near the Museum can have an impact on the condition of the remains. Other factors, like the air conditioning and heating inside the Museum at the basement level, and the presence of visitors (several million since the Museum opened) also affect the integrity of the remains.

To plan its actions and preventive measures, the Museum team implemented a monitoring program in 2009, consisting of systematically collecting long-term information concerning the moveable and immoveable remains within its walls. The program serves a basis for planning conservation measures and decisions regarding conservation policies, and gives an ongoing picture of the condition of the remains and their environment.

Observations of the various and cumulative problems in the remains over the past three years revealed the need for this kind of program. In the crypt, moisture on the old paved surface in the marketplace was affecting the soil between the stones. In the Éperon building, the floor of the Royal Insurance Company Building (stone slabs) where staff and visitors circulate has been settling in certain places, in particularly near the cemetery and the tower. This situation harms the old masonry – some large cracks have been detected – and could eventually have an impact on the contemporary parts of the Museum.

The program consists of a series of concrete measures, in particular the installation of a large number of thermohygrographs at strategic places in the remains (crypt, collector sewer, Éperon building) and detailed 3D surveys of the remains and especially any anomalies observed. This allows us to track or stabilize such anomalies and detect any new problems.

The goal of the project is to improve and standardize the process of monitoring the heritage treasures showcased in the Museum’s permanent exhibition in the remains. The program will help us safeguard the remains and give us a better idea of conditions, so that we can protect the integrity of the site, today and in future.