Restoring Natural Slate Roof Takes Expert Craftsmanship

Photos: Charles F. Evans Company Inc.

When it came time to replace the roof on Howard W. Jones Hall, Youngstown State University wanted to closely re-create the original graduated natural slate roof. Photos: Charles F. Evans Company Inc.

Even slate roofs have to be replaced sometime.

Howard W. Jones Hall is one of the oldest buildings on the campus of Youngstown State University in Youngstown, Ohio. The limestone structure with its twin towers is an iconic structure, and when the original slate roof finally deteriorated, the university wanted to keep the stately look of natural slate on the building’s exterior.

Charles F. Evans Company Inc. of Elmira, N.Y., was awarded the Jones Hall restoration job in early 2017 and named 37-year veteran Ken Dennison as the project manager. “We seem to excel in doing difficult projects, including specialty systems of slate, tile, and architectural sheet metal,” Dennison says. “We emphasize quality workmanship and uncompromising customer satisfaction. We also emphasize safety, and currently we are the only roofing contractor to be an approved OSHA VPP mobile Mobile Workforce STAR contractor.”

The university wanted to replicate the existing 6,500-square-foot graduated slate roof with random widths, and slate roofing tiles in the same color and size range were chosen. The scope of work included repairing the existing masonry and installing copper gutters, valleys and flashings.

Going Old School

The first step was removing the old slates, which proved a tough task. “We had to remove them almost one by one,” recalls Dennison.

Copper details were custom fabricated for counterflashing and step flashing.

Copper details were custom fabricated for counterflashing and step flashing. Photos: Charles F. Evans Company Inc.

The existing wood plank deck was in very good shape, and Carlisle Water & Ice Protection self-adhering underlayment was installed at the eaves, valleys and rakes. It was also applied around all of the details. Then two layers of 30-pound felt were tacked into place with plastic-capped nails.

Natural hand-split roofing slate was delivered pre-cut and pre-punched by Evergreen Slate Co., located in upstate New York. The slates were mixed to ensure proper color distribution and arranged in piles for installation on the site. Once the underlayment was in place, the slate was installed just as it might have been a century ago. “We used copper nails,” Dennison notes. “Everything was nailed by hand—two nails per slate.”

The installation called for a 3-inch head lap. “With random slate, you don’t need to put any vertical lines in, because nothing is going to line up vertically,” Dennison explains. “Every side lap has to be at least 3 inches, but there is no set pattern for the widths—we just mix them up. That’s why they use the term ‘random.’”

Handcrafted copper details completed the distinctive, traditional look. Flat-seam copper panels from Revere Copper were installed in the valleys, using clips to allow for expansion and contraction. Copper counterflashing and step flashing were also custom fabricated. “We bend it to fit whatever we might need,” notes Dennison. “We have a talented sheet metal shop at our office where we fabricate the big stuff, but we also cut and shape panels on site.”

Photos: Charles F. Evans Company Inc.

Photos: Charles F. Evans Company Inc.

A detailed safety plan was set up for the building, which was open and active during the entire installation process. Scaffolds with decking were erected at the eaves, and temporary tunnels were engineered to protect pedestrians at the entryways.

The rake edges did not have scaffolding, so a safety perimeter was set up 6 feet from the roof edge. Workers outside the line had use a personal fall arrest system, which was secured to anchors screwed into the rafters. “All of our mechanics are extensively trained, and each year everyone goes through additional training sessions,” Dennison says. “We all know what we’re supposed to do. We have a very stringent plan on project safety.”

Slate itself can pose its own set of safety concerns. “Slate can be heavy and sharp,” Dennison says. “It’s rock. You have to be very careful, but the guys that do it love it. A lot of roofs these days are totally hidden. On a slate project, at the end of the day you can step back, see what you’ve done, and be proud your work.”

Charles F. Evans is just putting the finishing touches on the roof at Jones Hall. “When we’re done with a project and the customer is happy, that’s the best satisfaction you can get,” Dennison says. “When the client is happy and you look back and see a beautiful product that you know you had a hand in—that’s what I like about it. A slate roof is really a work of art that will stand the test of time.”

TEAM

Architect: eS Architecture and Development, Dublin, Ohio, esarchitecture.com
Roofing Contractor: Charles F. Evans Company Inc., Elmira, N.Y., Evans-roofing.com
Slate Supplier: Evergreen Slate Co. Inc., Grandville, N.Y., Evergreenslate.com
Copper Supplier: Revere Copper Products, Rome, N.Y., Reverecopper.com

Project Profiles: Retail

Sierra Nevada Brewery, Mills River, N.C.

About 58,000 pounds of copper were installed on the brewery.

About 58,000 pounds of copper were installed on the brewery.

TEAM

Roofing Contractor: The Century Slate Roofing Co., Durham, N.C.
Architect: Matthew Galloway of Russell Gallaway Associates Inc., Chico, Calif.

ROOF MATERIALS

Approximately 423 squares of 1/2-inch-thick, 18-inch-tall by random width Unfading Green Slates were installed by hand on the project. This was close to 750,000 pounds of slate, or 375 tons.

About 3,000 feet of custom copper gutters and downspouts, conductor heads and 100 squares of painted standing-seam panels were fabricated, and pre-built copper clad dormers and decorative copper cornices were installed.

The project also included 35 squares of copper standing-seam roofing, 25 squares of soldered copper flat-seam roofing and 115 squares of copper wall cladding. About 58,000 pounds of copper were installed on the brewery.

Everything on the building is oversized and that meant everything had to be built to support the heavy structural loads and live loads from wind and mountain snow. The large roof faces called for 10-inch custom copper gutters. When you have gutters that large in the mountains of North Carolina you have to consider the extraordinary weight of the annual snow.

In addition to snow guards being installed on the slate roof, custom 1/4-inch-thick copper gutter brackets fastened the gutter to the fascia. It is typical on steel-framed construction, particularly on this scale, that the framing is out of square and there is widely varying fascia and rake dimensions.

Approximately 423 squares of 1/2-inch-thick, 18-inch-tall by random width Unfading Green Slates were installed by hand on the project.

Approximately 423 squares of 1/2-inch-thick, 18-inch-tall by random width Unfading Green Slates were installed by hand on the project.

However, these items should not appear out of square or have varying dimensions. Great care had to be taken to measure and custom bend onsite all the detail flashings so everything appeared perfect. This took many skilled craftsmen, a great deal of time and the absolute drive to provide the highest quality work.

Slate Manufacturer: Evergreen Slate Co. Inc.
Copper Fabricator: K&M Sheet Metal LLC
Supplier of Underlayment, Copper Sheets and Coil, Insulation and Nailbase Sheathing: ABC Supply Co. Inc.

ROOF REPORT

The new-construction project began in November 2013 and was completed in September 2015.
The team completed the slate installation so well that The Century Slate Co. was awarded the 2015 Excellence in Craftsmanship Award by Evergreen Slate for the project.

PHOTOS: The Century Slate Roofing Co.

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