Soldiers in green fatigues, hard hats and harnesses are climbing the walls of St. Alphonsus Church in Victoria Mines, Cape Breton.

CFB Gagetown's 4 Engineer Support Regiment is replacing the roof of the 101-year-old building known as the Stone Church.

The construction project is part of Exercise Nihilo Sapper 2017, an annual engineering exercise that gives members hands-on technical training to make sure the military is ready to deploy soldiers when called upon.

The Stone Church with scaffolding

The scaffolding to reach the roof is six metres high. (Yvonne LeBlanc-Smith/CBC)

The president of the volunteer Stone Church Restoration Society, Melanie Sampson, said she was "overjoyed" at the sight of soldiers climbing the six-metre scaffolding and tearing off the old shingles.

"I'm overwhelmed. I am absolutely overwhelmed."

Sampson said she convinced the military to take part in the project, but it wasn't until Thursday morning that the Roman Catholic Diocese of Antigonish agreed to let the work begin.

She said the military would have done even more if the society had been given the deed to the church.

Stone Church with soldiers

The soldiers will work on the church for two weeks. (Yvonne LeBlanc-Smith/CBC)

"They were willing to do not only the roof, but the electrical and the heating upgrades," she said.

The society has been negotiating with the diocese for three years to buy the church.

About a dozen soldiers will rotate the work on the roof with other projects around Cape Breton. It is expected to take two weeks to complete the job.

Capt. Jamie Tobin said the regiment supports the Disaster Assistance Response Team (DART).

"That team will often be called at short notice to deploy anywhere in the world that has been struck by natural disaster," he said.

"When they do get to those locations, it's very often the case where they have to assist with infrastructure repairs, infrastructure restoration."