Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Photo courtesy of GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico.
Kellogg Co. is the world's leading cereal manufacturer and a leading manufacturer of many other convenience foods. Although the company began with only 44 employees at a facility in Battle Creek, Mich., where its headquarters remain, Kellogg's products now are manufactured in 18 countries and sold in more than 180 countries.
One of Kellogg's facilities, Kellogg de México, a cereal manufacturing plant in Queretaro, Mexico, began experiencing roof leaks in 2009, and the company decided the facility needed to be reroofed. Conley Group Inc., Irving, Texas, was hired as the reroofing project's consultant, and Steve Drennan, Conley Group's project manager, invited GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico, to bid on the project.
After attending a pre-bid meeting, GRUPO CUBIMSA Professional Roofing submitted its bid and won the reroofing project. The company was asked to tear off the facility's existing roof system to the concrete deck and install a protected polymer-modified bitumen roof system.
Extreme measures
GRUPO CUBIMSA Professional Roofing began tearing off Kellogg de México's 186,000-square-foot existing roof system in May 2009; it was an extensive undertaking.
First, crew members using fall protection and wearing personal protective equipment installed 65- by 65-foot tarps over the existing roof areas to act as tents so workers could remove the roof system without contaminating the plant's processes with any possible rainwater leaks. The tarps weighed about 220 pounds each.
"Once installed, the tarps constantly had to be supervised," says Miguel Arzola, GRUPO CUBIMSA Professional Roofing's chief operations officer. "They were drained after each rain to avoid pulling down the entire roof system. Additionally, sometimes the wind would tear them and they had to be replaced."
GRUPO CUBIMSA Professional Roofing also installed a reinforced 6-mil-thick polyethylene protective layer inside the plant to prevent equipment damage and product contamination.
"Because it is a food manufacturing plant, hygienic measures had to be extreme," Arzola says. "Internal protection was used to prevent any dust, dirt or debris from contaminating the products, as well as protect the equipment. Any product line contamination would have required cleanup of the entire line, 48 hours of observation and bacterial testing."
After installing interior and exterior protection, crew members began removing the existing roof system.
"All the facility's internal production process equipment is on the roof, so removing the existing roof system required extreme measures," Arzola says. "We had up to 180 workers involved during peak times to allow tear-off of the existing roof system and installation of the new roof system to progress simultaneously."
Workers used jackhammers to remove the existing roof system, which consisted of volcanic rock layered to provide slope; 3-inch-thick structural concrete; two-ply polymer-modified bitumen membrane; 3/4-inch face brick; and a concrete slurry coating. The system was between 9 and 14 inches thick.
"Debris was bagged to avoid dust," Arzola says. "Each load weighed more than 110 pounds. Loads were carried 1,000 feet across the roof and lowered 65 feet to the ground in some areas.
"At maximum working capacity, we removed about 10,600 cubic feet of the existing roof system in one shift, filling 12 trucks," he continues.
Layer by layer
As tear-off progressed, crew members began installing the facility's new polymer-modified bitumen roof system.
First, crew members cleaned and primed the existing concrete deck with asphalt primer. Then, a Firestone Building Products APP 160 smooth-surfaced polymer-modified bitumen membrane was torch-applied to the deck as a temporary roof.
"We then flashed typical details such as parapet walls, roof curbs, gutters, drains and scuppers with Firestone Building Products' EPDM FormFlash membrane for flexibility," Arzola says. "We had special approval from the manufacturing company in that regard.
"Tear-off of the existing roof system, APP 160 installation and flashing of details were performed concurrently," he continues. "Entire roof areas that were removed had to be sealed by installing a temporary roof system formed by the APP 160 layer and flashing details given the irregularity of the equipment's bases."
Next, crew members installed a Siplast tapered lightweight insulating concrete system, which consisted of applying a lightweight insulating concrete slurry, molded expanded polystyrene insulation board and lightweight insulating concrete top-fill.
"The lightweight concrete was pumped vertically about 65 feet, and we used about 1,000 feet of hose," Arzola says. "This was difficult because of the amount of equipment on the deck.
"After pouring the lightweight insulating concrete, we removed the covering tarps and moved them to areas where work was to be performed next," he continues.
Then, crew members installed Firestone Building Products' APP Premium Base—a nailed, vented APP polymer-modified bitumen base sheet—with appropriate fasteners over the lightweight insulating concrete system. An intermediate APP 160 polymer-modified bitumen membrane was torched over the APP Premium Base.
"The APP Premium Base and APP 160 were installed on the same day because the base sheet could not be exposed," Arzola says.
Crew members torched a Cap Sheet APP 170 polymer-modified bitumen membrane over the previous membranes to help avoid damage from roof traffic. Additionally, an APP 180 membrane was used to flash more than 6,000 details. New bi-level drains then were installed and equipment supports replaced.
"Once the APP 170 was installed and the details had been flashed, we installed a Carlisle Coatings & Waterproofing CCW MiraDRAIN® GR9200 drainage mat," Arzola says. "Three-inch-thick, fiber-reinforced concrete immediately was installed over the roof system to prevent damage from traffic or wind."
Many consistency and compression tests were performed while pouring the reinforced concrete.
"Once the concrete installation was complete, control joints were cut to prevent the concrete from cracking," Arzola says. "Control joints were cut on a 20- by 20-foot grid—269,000 linear feet total—and each control joint was filled with backer rod and NP1 sealant."
Crew members then flashed the expansion joints, which had to be done meticulously because the joints are located over critical food processing locations inside the building. Additional areas then were coated with United Coatings' Roof Mate elastomeric coating.
Put to the test
Despite the challenges GRUPO CUBIMSA Professional Roofing faced during the project, crews finished reroofing Kellogg de México on time.
"Our crews never interfered with the plant's processes, and work was completed May 22, 2010," Arzola says. "The project tested our capability, creativity, patience and expertise as a company and individuals.
"Javier Perez, Ruben Mares and Francisco Marrero, our project manager, regional manager and construction manager, respectively, were instrumental during this project," he continues. "Additionally, Bill Conley, Conley Group's owner; Bill Moran, Conley Group's site supervisor; Bernardo Camacho, Kellogg's Queretaro engineering manager; Pablo Calvo, Kellogg's Queretaro plant manager; Hector Padilla, Kellogg's safety engineer; Sergio Rosas, Kellogg's project engineer; Miguel Ángel Lopez, Kellogg's Latin America facilities manager; and Tim Stafford, Kellogg's Latin America engineering director, deserve special thanks."
For its excellent work on the facility, GRUPO CUBIMSA Professional Roofing received a 2011 NRCA Gold Circle Award in the Outstanding Workmanship: Low-slope category.
"We always try to do our work with passion and excellence, so being recognized and trusted by our clients is great because it is a sample of their satisfaction," Arzola says. "The Gold Circle Award also represents appreciation from people and companies who do the same work we do, which is rewarding. But there's nothing like the appreciation, recognition and support of our customers."
Ashley St. John is Professional Roofing's associate editor.
Project name: Kellogg de México
Project location: Queretaro, Mexico
Project duration: May 25, 2009-May 22, 2010
Roof system type: Polymer-modified bitumen
Roofing contractor: GRUPO CUBIMSA Professional Roofing Co., Chihuahua, Mexico
Roofing materials manufacturers: Carlisle Coatings & Waterproofing, Wylie, Texas; Firestone Building Products Co. LLC, Indianapolis; Siplast, Irving, Texas; and United Coatings, Phoenix
Gold Circle Award category: Outstanding Workmanship: Low-slope
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