Historic renovations are always challenging, especially when the building is listed on the National Register of Historic Places. But when the renovation requires part of the building to be removed, stored on site, repaired and re-installed to the original specifications, and new slate to be installed on steep sloped round turret roofs, that takes the project to a whole new level.
But that’s exactly what happened with the Green County Courthouse in Monroe, Wisconsin.
The classic Richardsonian Romanesque-style Courthouse was built in 1891 from red brick and limestone. It is a large, asymmetrical two-and-a-half story structure that includes two steeply sloped round turret roofs, a steep slope square pyramid turret, as well as a 120-foot square ‘clock tower’ with a steep pyramid roof — all typical features of the architectural style.
A Restoration to Historic Natural Beauty
The building has had some issues over the years: in the 1950’s, the clock tower’s peaked roof blew down in a windstorm. It was repaired and re-installed with a standing seam metal roof, and the original slate roof on the rest of the structure was replaced with asphalt shingles.
Renaissance Historic Exteriors was hired to restore the Courthouse to its original design with a natural slate roof. Ultimately, the project would include not only the installation of some 18,000 square feet of ¼-inch thick, 20-inch tall by 10-inch wide slate to match the original design and aesthetics of the historic courthouse. The project also involved replication of the original copper finials, cornices, flashing, gutters, and downspouts, as well as extensive structural and masonry repairs.
The Right Slate for the Job
For the historic restoration project, Renaissance specified North Country Unfading Black Slate Tiles, from North Country Slate in Ontario, Canada, to match the original slate roof and ensure the historical accuracy and integrity of the project. Unfading Black Slate tiles are exclusively available through North Country Slate and only produced in one quarry. The premium roofing slate not only offers a rich black color with a slight luster but also has a long and successful track record of performance, having been used for decades in both new construction and historic renovations around the world.
North Country’s Unfading Black slate is rated as an S-1 rated roofing slate and exceeds ASTM’s requirements for roofing slate. The ASTM specification sets standards for the physical properties of the slate, including water absorption, weather resistance and breaking load, as well as tolerances for planarity, squareness and dimensions. It also comes with a guaranteed service life of 75 years.
Renaissance had to erect a significant scaffolding system and rely on man-lifts and elevated platform ‘decks’ to install the new slate roofing, particularly on the steep slopes and high elevations of the round and pyramid shaped turret towers. Their extensive expertise in traditional, old-world construction techniques, along with superb craftsmanship, were critical to this renovation project, and in giving the old Courthouse new life.
The project included removing the clock tower’s pyramid-shaped roof structure by crane and storing it on the courthouse grounds until it was rebuilt and replace into position before having the new slate roof installed.
Hower, the most challenging part of the project was installing the slate tiles on the steep conical shaped turret roofs, which required a high level of craftsmanship and expertise. For the slate to lay flat on the curved surface, the team had to snap lines from the top center of the cone shaped roof and then hand trim the upper corners of each slate tile for a perfect fit. All while standing on a narrow six-inch wide platform ‘deck’ secured to the roof.
Top of the Mountain
The hard work was all worth it in the end, as Renaissance was awarded the 2025 Gold Circle Award for Outstanding Workmanship on a Steep Slope Roofing Project. Gold Circle Awards are presented annually by the National Roofing Contractors Association to recognize outstanding achievements in all facets of roofing design and construction. North Country Slate is proud to have been the supplier for yet another Gold Circle Award-Winning roofing project.
North Country Slate was the perfect partner for this project and will be your perfect partner, too. Their slate is 100% natural, highly resistant to moisture and chemicals, unaffected by freeze/thaw cycles, and non-combustible with a Class A Fire Resistance Rating. In short, North Country Slate can add beautiful aesthetic appeal and 75 years of life expectancy to any structure, as it did for the Green County Courthouse.
