Riddiford Roofing of Arlington Heights, Ill., has been in business for more than a century. Today the company installs practically every type of commercial roofing system.

Riddiford Roofing installed metal replacement roofs on three school buildings in Manteno, Ill.Here the 22-gauge steel panels are lifted to the rooftop. Photos courtesy of Riddiford Roofing Company


Riddiford Roofing of Arlington Heights, Ill., has been in business for more than a century. Today the company installs practically every type of commercial roofing system - from traditional asphalt built-up roofing systems to the latest designs of metal roofing systems - on buildings throughout the Midwest, including Illinois, Indiana, Iowa and Ohio.

George Riddiford is the President and CEO. His grandfather and a partner formed Murdock Roofing Company on Chicago’s South Side in 1901 and his father founded Riddford Roofing in 1964. Nowadays, Joe Riddiford and Chris Riddiford are Vice Presidents, continuing the family tradition through four generations, a rarity in any business.

Four generations of Riddifords not only witnessed 100 years of changes in the roofing industry but also led the way in the adoption of new materials and new technology. Such is the case in the re-roofing of schools in the Manteno Community Unit School District 5, located in Manteno, Ill., on Interstate 57, approximately 50 miles south of Chicago. The district is made up of four schools, educating over 2,200 students in pre-school through grade 12.

Tarco LeakBarrier PS200HT self-adhering underlayment was installed on the project. The peel-and-stick product was specially designed for use under metal roofing, is watertight, and can withstand high temperatures.

A High Achiever

Riddiford Roofing successfully bid on a large metal re-roofing project, including the elementary school (900 squares), the middle school (25 squares) and the high school (175 squares) for a total roof area of 110,000 square feet.

New roofs comprised of McElroy 22-gauge, standing-seam steel panels were to be installed on the school buildings. The existing 24-gauge, standing-seam panels had to be torn off.

According to Joe Riddiford, Vice President of Riddiford Roofing, purchasing and evaluation of roofing products is usually driven by the architect’s specifications. The specification and McElroy allowed the roofer to install either a new 30-pound felt or a self-adhering underlayment. “We probably could have saved a few dollars in materials by using 30-pound felt,” said Riddiford, “but the self-adhering underlayment offered many important benefits.”

Riddiford explained that 30-pound felt does a good job at shedding water but that it does not provide a watertight covering. “We had a very wet June this year. We were very concerned about the underlayment getting wet before we could install the metal panels,” he said. The wet weather motivated him to inquire about using a self-adhering underlayment instead of 30-pound felt. “That’s when a representative from our sheet metal company told us about the Tarco PS200HT underlayment.”

Both the architect and the metal roof manufacturer approved the use of Tarco LeakBarrier PS200HT self-adhering metal underlayment. “The architect is the eyes of the school district,” said Riddiford, “so we needed his approval as well as the approval of the metal roof manufacturer.”

Choosing the self-adhered underlayment was an easy decision to make. The underlayment was specially designed for use under metal roofing. It is a peel-and-stick product with a high softening temperature. In other words, it remains stable up to 260 degrees Fahrenheit as measured by ASTM D-5147. This stability is crucial because temperatures can soar beneath a metal roof. In addition, its polymer surface slides beneath the metal roofing without abrading.

The metal roofing manufacturer had approved 30-pound felt as an underlayment and Riddiford could have gone along with that original specification. Yet, the self-adhering underlayment was clearly a superior product and, in the end, its advantages and convenience outweighed any consideration about material costs. The school district would benefit from the performance of a premium, watertight, self-adhering underlayment, and the roofer would benefit as well.

While some sections of the roof have slopes of 6:12, most of the roof areas have slopes of 2:12. The peel-and-stick underlayment provides a watertight barrier, which is especially important for the low-sloped sections.

No Fishmouthing, Please

For metal-roofing, a premium underlayment allows contractors to add value while minimizing added labor. Contractors can offer building owners a significant upgrade without a major increase in the overall job cost.

Riddiford and his field technicians were astonished at how easy the self-adhering underlayment was to handle. “There were no fishmouths. The underlayment remained flat with no curling at the ends,” he said. In roofing parlance, a fishmouth is a half-cylindrical or half-conical shaped opening or void in a lapped edge or seam, usually caused by wrinkling or shifting of ply sheets during installation.

“The premium underlayment adhered very well and it didn’t take any longer to install,” he continued. “We were not hindered in any way using the premium underlayment compared to using the 30-pound felt. In fact, in terms of the entire project, productivity increased.” He explained that he had projects in the past where there were a lot of problems with the 30-pound felt. “When 30-pound felt is exposed to rainy weather, a lot of time is wasted, because the damaged felt has to be torn off and new felt applied. The 30-pound felt does not hold up well in wet weather. It begins to warp when left exposed for just a couple days to inclement weather.”

Labor-saving materials and techniques are highly valued by contractors. “Productivity is dramatically improved by eliminating the extra labor required when the 30-pound felt is exposed to wet weather and has to be replaced because of warping,” Riddiford noted. “The self-adhering underlayment is a lot more productive than 30-pound felt when that extra-labor factor is taken into account.”

Another factor in selecting a premium underlayment is the adhesion strength. The “right” amount of tack can be subjective and preferences vary among roofers. Some contractors prefer lower adhesion, which allows for easier re-alignment if the sheets are initially misplaced; others prefer stronger adhesion to ensure a good grip to a particular material or slope. For many installers it is a matter of what feels right, and one membrane is often chosen over another because of the contractor’s familiarity with the product. “The PS200HT product adhered well and yet was easy to handle,” said Riddiford.

Riddiford confided that he was a lot more confident with the self-adhering underlayment. “The school district is getting a much better roofing system,” he commented. “Most of the roof areas have slopes of 2:12, although some sections slopes have slopes of 6:12. The 30-pound is only meant to shed water but the peel-and-stick provides a watertight barrier, which is especially important for the low-sloped sections.” Windblown rain could build up and seep through the 30-pound felt. The underlayment also has the advantage of adhering exceedingly well to the deck and sealing around nail holes. The combination of the metal roof protecting the watertight secondary water barrier ensures there will be no leaks for a very long time. The metal roof protects the underlayment from ultraviolet radiation and wind-blown debris; meanwhile, the underlayment prevents water intrusion into the building.

Riddiford further elaborated on the issue of rainfall during installation and how that can affect productivity. “The Manteno area saw a lot of storms this past summer,” he said. “The underlayment was exposed on a lot of roof areas for a period of time during and after the storms. We cannot always install the metal panels on the same day. Until we catch up with the steel panels the underlayment is exposed. I am a lot more confident with the PS200HT product in these circumstances. It was much easier to phase in the installation of the steel panels with the installation of the PS200HT underlayment.”

Change for the Better

Four generations of Riddifords have seen a lot of changes in the roofing industry. The company has roofed many landmark buildings in downtown Chicago and expanded the business both in terms of the types of roofs it installs and geography.

The roofing industry tends to be conservative because failures of commercial roofing systems can be costly. Nonetheless, when a new technology emerges that provides superior performance and is easier to install then it will be quickly adopted. As has often been the case in the past 100 years, Riddiford Roofing is leading the way. That’s why it’s one of the largest commercial roofers in the Midwest - and still growing.


For more information about Tarco, visit www.tarcoroofing.com. For more information about Riddiford Roofing, visit www.riddiford.com.