REGINA -- The Saskatchewan Legislative Building is made of dolomitic limestone, more commonly known by it’s trademarked name, Tyndall stone. The province said cleaning the heritage property is tricky.

Government officials said the approach is tailored to every specific cleaning need. The stone does have environmental build-up on it from time to time, which sometimes comes from the stone itself. You may see a black film form at points, that’s a good example of environmental build-up. Staff report it’s common for the exterior stone to require multiple cleanings because it’s quite porous.

The province said all methods of maintenance and cleaning are non-invasive in order to maintain the building’s integrity, history and to avoid any environmental impact. Due to several issues that may a tailored approach, that’s about as specific we can get without writing a small novel.

It’s a mixture of painstaking brushing, scrubbing and repeating, for most issues.