The scaffolding will be removed from the facade of Notre-Dame Basilica in Montreal

After close to ten years behind scaffolding, the Notre-Dame Basilica in Montreal is preparing for the grand unveiling of its facade, scheduled for October 25.

While the restoration of the facade is complete, the basilica still has several years of work ahead of it. About 20 per cent of the necessary work has been completed, said Michel Issa, executive director of the Fabrique de la paroisse Notre-Dame de Montréal.

He estimates that work on the exterior of the church will take four years, but said this figure may be optimistic. The interior restoration of the basilica might take another five to ten years, he said.

The total cost of the restoration will add up to $100 million, said Issa. To fund this work, the basilica organizes benefit concerts, generates revenue from its coffee shop, Le Firmament, and holds fundraisers.

The latest fundraising campaign is based on a new idea: leaving a virtual mark on the church’s stones.

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Donors have the option to “sponsor a stone” and inscribe a digital message on the building’s facade.

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“We would have liked to engrave the stones themselves, but unfortunately, that’s a logistical nightmare that’s impossible to pull off,” said Issa, adding that the process would reduce the stones’ durability.

The messages will be viewable using a cellphone directly on the church’s facade via augmented reality, or elsewhere by projecting a model of the facade onto a flat surface. Issa compared this augmented reality process to the one used by the viral app Pokemon Go.

People can already sponsor a stone, but the messages will not be viewable until early 2027.

The renovations come with this steep price tag because they involve the entire structure of the basilica.

“All the masonry in the building needs to be reinforced and restored,” said Mathieu Verreault, director of tourism and operations for the basilica.

“After years of freezing and thawing, the stone has cracked in several places.”

The stones used to build the basilica came from an old quarry in the Mile End neighbourhood of Montreal. Those placed higher up were salvaged from the bottom of the quarry and were of lower quality, said Verreault.

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On top of that, some were placed “the wrong way.”

“It’s sedimentary stone, so there are layers, and they have to be laid horizontally. If you lay them vertically, the stones are more permeable to rain,” he said.

Some of the mortar that held the stones in place was also replaced with epoxy, which put greater pressure on the stones.

“People were doing the best they could with the knowledge they had at the time, and, of course, in the long run, all these choices — which have proven questionable over time — have led to the situation we see today,” said Verreault.

These exterior weaknesses also affect the interior, with water infiltration and moisture problems leading, for example, to the deterioration of painted decorations.

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These are not being repainted. Instead, the parish is attempting to reattach each flake of paint.

“(It’s) very labour-intensive, very time-consuming, but it’s best practice in heritage conservation,” said Verreault.

The basilica’s star-studded blue vault is among the sections that will need to be restored.

“We’re talking about scaffolding about ten storeys high, which means our concerts and tours will most likely be interrupted,” which will cut off the church’s revenue, said Issa.

If all this work is not done, the deterioration threatens to progress exponentially, causing even more problems in the future.