Ten years ago, Cort and Helene Dondero finished building their dream home in Chattanooga, Tenn. — a sprawling, 20,000-square-foot modern-day castle overlooking the Tennessee River. The home’s original roof featured cementitious roofing tiles, which emulated the look of a traditional slate roof. Unfortunately, the tiles had a manufacturing defect and became very brittle over time.

They were severely damaged during a hailstorm in 2010, with several pieces breaking off and falling to the ground or slipping into gutters.

The tiles were under a 50-year warranty, but when the homeowners contacted the manufacturer, they found that the company had gone out of business. Fortunately, the roof damage was covered by their policy with Chubb Insurance, and they began carefully comparing real slate tiles with durable slate-alternative roofing products the insurance company recommended. In the end, they chose CertainTeed® Symphony™ roofing shingles. Symphony is a composite roofing product that mimics the look and feel of natural slate, but is lighter, more durable and has a lower installed cost. Unlike traditional slate, it has excellent weathering qualities, withstands foot traffic and cold temperatures and resists curling.

“We were looking for a slate-like roofing material that would have much better resilience and longevity than our previous roof tiles,” Cort Dondero said. “Symphony was one of two products Chubb Insurance recommended to us, and we liked the look of it, as well as its warranty. We contacted CertainTeed to ask about certified installers of their product, and they gave us the names of two local roofing contractors.”

The homeowners hired Sprout Roofing, of Signal Mountain, Tenn., which agreed with their product choice for a durable slate-style roof.

“I felt Symphony was the better product, not just because of the quality and the price, but also because of the way CertainTeed stands behind its products,” said Joe Sprout, owner of Sprout Roofing. “If there is a problem, they always respond, and they respond quickly. It’s one thing to say you have a warranty and another to actually do something about it when a problem arises.”

Sprout Roofing began work in August 2012, with a roofing crew of six and a painting crew of three, and encountered the biggest challenge of the project — accessing a roof with a maximum height of more than 70 feet and maneuvering the necessary heavy equipment.

“We had to use 45-, 60- and 80-foot hydraulic lifts, in addition to a standard roofing lift, to bring materials up and jobsite waste down. We couldn’t just throw the old roofing material down, due to the height of the roof and the weight of the tiles,” Sprout said. “We used the larger lifts in the front and the smaller in the back because the larger equipment was about 2 inches too wide to pass through the arched stone breezeway that was our only path to the backyard. When we were in front of the house working from the boom, the 80-foot lift was just barely tall enough to reach the highest point of the roof.”

To ensure safety, the crews wore OSHA-compliant harnesses and ropes. The painting crew began by washing the parapet walls and painting a portion, while the roofing crew removed the old roofing tiles and roofed one section, all to give the homeowners a visual sample of the finished product for their approval. With the Donderos’ blessing, the crews moved ahead. The full CertainTeed roof system, from bottom to top, consisted of DiamondDeck™ high-performance synthetic underlayment, Flintlastic® SA PlyBase self-adhering base sheet and 105 squares of Symphony shingles in a color mix of 85 percent Colonial Gray and 15 percent Capital Blend. The crew also installed CertainTeed’s Symphony hip and ridge accessory.

Instead of ice and water shield under the painted aluminum in the roofs eaves and valleys, the crew installed Flintlastic® SA PlyBase for its extra thickness to accommodate the heavy foot traffic over the roof. The roofing crew had a positive experience installing the roofing materials. The crew members were particularly impressed with the water resistance of the DiamondDeck underlayment.

“On most of the roofs we work on, we’ll tear off the old shingles and roof in the same day so we won’t have to worry about the new underlayment being exposed to the elements. Most standard roofing felts would be damaged by a good rain,” Sprout said. “With the DiamondDeck underlayment, we were able to tear off the old roof, install the underlayment and start putting on the shingles without having to worry if there were underlayment sections left exposed at the end of the day. We’d done another job where we’d left the product exposed for five weeks while there was some heavy wind and rain, and it was dry as a bone after we got back.”

This was the crew’s first experience with Symphony, and it turned out to be a good one. “We loved it,” Sprout said. “It’s just so much easier to work with than real slate.”

The roofing crew also installed 108-inch-tall custom-fabricated copper exhaust pipes, custom copper chimney shrouds and copper gutters and flashing. Most of the copper was treated to expedite the patina process. Despite the challenges of the roof height, tight corners, eight gables and a steep 12/12 roof pitch, the project moved along very well, aided partially by the ample time frame the contractor was allowed.

“The homeowner requested that we use a small crew and just work systematically around the house, as opposed to using a large crew and creating more commotion but getting it done quicker,” Sprout said. “We agreed to two months, but we finished in four weeks, so he was pretty happy.”

The homeowners are pleased with the look of their new roof, with its vibrant color blends and 8-inch shingle exposures.

 “Truly, when you look up at the roof, it does look like a real slate roof — 99 percent of people would not be able to tell the difference,” Dondero said. “And, I feel confident that we’ve now got a roof that will handle a hailstorm, backed by a warranty that will outlast us.”