Five warehouse buildings erected in the early 1900s were converted into mixed-use rooms in 1980. The complex was equipped with a new roof system in 2020. Photos: Central Roofing Company
In the trendy North Loop area of Minneapolis, the Warehouse District is anchored by condominiums from Itasca Lofts. The converted warehouse is more than 100 years old and houses 71 residential units as well as a restaurant, a comedy club and commercial space on the first floor. Six stories high, the structure’s old roof failed until Encompass Inc. and Central Roofing Company stepped in to help.
Itasca’s five warehouse buildings were built in the early 20th century and converted into mixed-use rooms by the Cuningham Group in 1980. Four decades later, age-related problems and leaks resulted in Itasca getting a new roof in 2020. The difficult project revealed layers of roof challenges.
“We first removed a built-up roof (BUR) that was probably 35 to 40 years old,” says Henri Germain, project manager at Central Roofing Company. “When we got to the original roof terrace, we were surprised to find that it was made of old, three-inch-thick boards. Today’s roof decks are made from half an inch of plywood. These original planks were an old style of tongue and groove. It’s fascinating to see how structures were built more than a century ago. “
Forensic Roof Review
Before the Central Roofing team began to cover the 30,000 square meter loft, Encompass was called in to analyze the faults in the roof system and oversee the construction. As part of a tendering process, they hired Central Roofing.
“At the beginning of the project there were various unknowns and unforeseen conditions,” says Ben Sandvig, project engineer at Encompass, Inc. “Central Roofing’s experience was evident and critical to the effective execution of this project.”
Obstacles on the roof
The challenging aspects of the project included numerous penetrations, curbs, paving stones and HVAC units on the existing roof.
According to Germain, the most difficult aspect of the project was machining dozens of different roof elements. There are various ducts, curbs, paving stones and HVAC units on the roof of the apartment. To make the job easier, a Potain crane was brought to the site.
“We first installed plastic on all of the interior ceilings to protect each home owner unit,” says Germain. “Then our foreman Adam Freitche and Superintendent Matt Tueffel led the effort to demolish all of the wooden decks and railings that belong to the owners of the top floor. After that, we removed the flashing on the parapets between the sections. Next, the old tar and gravel roofing system was taken out down to the wooden boards. “
Rebuild the roof
To begin rebuilding the roof, the Central team used a variety of Johns Manville products. The fully bonded roof system contains a 90 mil EPDM to reduce the potential for future leaks. JM Enrgy 3 3-inch ISO insulation was installed along with a 30-inch cover board. The roof system comprised a JM Vapor Barrier SA.
Over the course of the working weeks, 17 Wasco and Velux skylights were installed and curbs raised to allow for the height of the roof. Walkway cushions and walkways have been installed at the roof entrance doors, as well as at the base and top of the stairs, to provide access to HVAC units. Paths have also been created for the top floor owners to access their newly built roof decks.
The Central team worked on the standout roof structures and installed 24 gauge Firestone Una-Clad sheet metal to create a roof with a stunning appearance. Just over five months of the canopy was completed in late August 2020.
After the roof was rebuilt, the leaks are gone and condo owners are enjoying their living space in the warehouse district again.
“The Encompass and Central Roofing teams worked really well together on this project,” said Brian Droske, association manager at FirstService Residential. “Our company has headed the homeowners association for Itasca Lofts for around 40 years. The owners of the condominiums on the top floor are particularly pleased with the roof renovation.
“These owners have the option to purchase a licensing agreement from the housing association that allows them to build roof terraces directly on their units. Some of these owners also have rooftop stairs that lead from their unit to their rooftop decks that overlook the Mississippi. The new roof and its roof terraces make these condominiums all the more valuable for the residents.
“Despite many challenges that everyone recognizes, this project was completed successfully. Central Roofing’s experience was evident and critical to the effective execution of the project given the various unknown and unforeseen conditions of the existing structure. “
Architect: Cuningham Group, Minneapolis, Minnesota, cuningham.com
Roofer: Central roofing company, Minneapolis, Minnesota, centralroofing.com
Consulting engineer: Encompass Inc., Minnetonka, Minnesota, includes ass.com
Membrane: 90 mil EPDM, Johns Manville, jm.com
Insulation: JM ENRGY 3 ISO, Johns Manville
Vapor barrier: JM Vapor Barrier SA, Johns Manville
Edge metal: Bare 24-gauge sheet metal, Firestone Building Products, firestonebpco.com