How to Achieve a Balanced Approach to Ventilation

Intake vents at the eaves allow cool, dry outside air to be drawn up into the attic, while exhaust vents at the ridge direct moist, warm air out of the attic and back into the environment. A balanced ventilation system, with equal distribution of intake and exhaust vents, helps optimize air exchange and prevents problems including ice dams. Photos: Owens Corning Roofing

What do blisters, bumps, and mole runs on a home’s roof have in common? Beyond detracting from exterior curb appeal, they may indicate a ventilation problem contributing to a range of comfort and performance concerns. Even the highest-performing roofing system will not deliver its full performance if a home’s roof is not properly ventilated.

Below, we look at how a balanced approach to ventilation supports a home’s structural performance and its occupants’ comfort. Balanced ventilation can prevent problems ranging from ice dams on a home’s exterior during winter to uncomfortable indoor humidity in the summer.

Ventilation supports the natural flow of air into and out of the home’s attic space. The forces of wind pressure and thermal effect work together to ventilate the attic. Intake vents allow cool, dry outside air to be drawn up into the attic, while exhaust system components direct the flow of excess heat out of the attic and back into the environment. A balanced ventilation system has an equal distribution of intake and exhaust vents (50 percent near the eave and 50 percent near the ridge), helping optimize air exchange and supporting effective thermal and moisture management.

Balance between intake and exhaust is key. Inadequate intake vents can cause negative air pressure air blowing across the roof surface to force higher pressure air to move outside the attic. As the displaced attic air needs to be replaced, insufficient intake ventilation will cause air to be drawn in through exhaust vents, potentially drawing in moisture/precipitation from outside.

Managing both the roof’s thermal and moisture profiles demands a balanced approach to ventilation. This balanced approach is comprised of three components: ample insulation, balanced ventilation, and controlled airflow through proper sealing and insulation — the ABCs of ventilation.

Ample Amount

The International Building Code (IBC) and International Residential Code (IRC) require a minimum ventilation ratio of 1:150 (1 square foot of vent area for each 150 square feet of attic/roof area). If certain requirements are met, such as balanced ventilation, the ratio can be reduced to 1:300. Always consult local codes for specific requirements. Owens Corning recommends a 1:150 ratio combined with balanced intake and exhaust ventilation. The free online Owens Corning ventilation calculator (www.owenscorning.com/en-us/roofing/components/vent-calculator) is a practical tool for informing insulation levels. By entering square footage or the metrics of the space, users can determine how much ventilation is required for the space.

Properly installed insulation supports a balanced approach to ventilation in the attic space.

Ample ventilation is about much more than code compliance. Properly installed, vents can help manage moisture that leads to performance problems. For example, in cold climates, high moisture levels inside (from showers, cooking, fish tanks, etc.) combined with cold outside air can cause frost to form on the interior of the roof deck, posing a risk for dry rot to occur. By keeping the roof deck temperature closer to the outdoor temperature, ventilation may also reduce ice dam occurrences, which can lead to water leaks on steep-sloped roofs. And in hot climates or during summertime, ventilation helps exchange hot attic air with cooler outdoor air, contributing to a more comfortable home.

Balanced Ventilation

Good ventilation requires a 50/50 balance between intake and exhaust vents to keep conditioned air inside the house and out of the attic. As exhaust vents (typically ridge vents or off-ridge vents) pull air out of the attic, the intake vents replace this “lost” air, drawing in air from outside. Location of the vents is also very important. Intake vents should be installed in soffits or lower on the roof slope near the eaves. An imbalance between intake and exhaust vents can create negative pressure in the attic, drawing in air from the conditioned part of the home via the ceiling, wall cracks, lighting fixtures and/or joints in the framing. This situation can result in a less comfortable indoor environment, lost energy, and higher heating/cooling bills. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation.

Controlled Airflow

The amount of moisture generated by human activities inside the average home is significant. A common estimate is that a family of four’s combined activities will contribute 1.3 gallons of water per day to the home’s indoor environment.

When trapped in various elements of the roofing system, liquid or vapor moisture contributes to problems ranging from structural damage to mildew and indoor odors. Similar to temperature differences, moisture in the air can lead to deck deflection as the wood in the roof deck deteriorates and warps. Too much humidity may also have a corrosive effect on metal components in the attic, including ductwork and HVAC equipment. Inside the home, high relative humidity may help facilitate the formation of mildew or peeling paint.

External Factors To Consider

In addition to proper balance of intake and exhaust vents, adequate insulation, and controlled moisture, other less-controllable factors may also influence ventilation rates — including variations in wind speed, wind direction, and surrounding topography. While higher wind speeds tend to increase ventilation rates, ventilation rates at a given wind speed may vary by a factor of 10. Ventilation rates are highest when the airflow/wind direction is perpendicular to intake openings. Ventilation rates decrease as wind direction becomes more parallel to the opening. Even topography can influence ventilation by influencing the speed and direction of wind. For example, the number and location of nearby structures, a home’s height, trees/vegetation, and variance in surrounding elevations can all affect the flow of wind. Predicting the impact of these factors requires sophisticated building science technologies, which can serve as useful tools for comparative analysis and help influence product innovations.

Modeling and Building Science

Owens Corning uses advanced technologies to inform ventilation approaches for mitigating thermal and moisture challenges. For example, computer simulations were used to evaluate how different ventilation strategies would impact attic temperature. Using AtticSim software, team members simulated temperatures in a Tampa, Florida attic during one week in July. The modeled attic had a gabled construction, measured 50 feet by 27 feet with a 4:12 roof slope, and had R-30 insulation installed in the ceiling. The analysis evaluated two ventilation schemes: one with balanced ventilation (soffit-to-ridge) and one with unbalanced ventilation (soffit-to-soffit only). As a “control” measure, a sealed attic (attic without vents at the soffit and the ridge) was also evaluated. Analysis reveals that temperatures in a sealed attic without any ventilation exceeded 140 degrees Fahrenheit. The balanced ventilation between intake and exhaust was effective in reducing temperature in the attic when compared to the soffit-only approach. The balanced ventilation reflected a temperature difference of more than 30 degrees when compared to the soffit ventilation approach.

What practical application can we make of this building science research to inform a ventilation strategy? This analysis shows the benefits of a balanced approach. When the roof’s intake and exhaust system is balanced, the benefit of wind pressure and buoyancy-induced ventilation work together to increase air exchange and lower attic temperatures. The unbalanced approach (soffit-to-soffit only) is more variable and does not lead to the same air temperature reduction. The unbalanced, soffit-only ventilation is less effective and appears to be impacted by changes in wind speed and direction.

At the end of the day, it doesn’t take a building scientist to understand the benefits of getting the ventilation right with a balanced approach. Balanced ventilation keeps homeowners more comfortable, contributes to the roof system’s proper functioning, and helps a contractor walk away with confidence, protecting both the businesses’ reputation and the bottom line.

About the authors: Lucas Console is Product Manager – Owens Corning Roofing and Greg Keeler is Technical Service Leader  Owens Corning Roofing. For more information, visit www.owenscorning.com/roofing.

Detailed Work on California Home’s Unique Roof Wins Prestigious Award

Photos: IB Roof Systems

Premium Roof Services was built on the philosophy that good relationships are good business. Founded in 1996, Premium Roof Services is proud of its team of skilled roofers, who have more than half a century of experience. Their level of quality workmanship was showcased on a recent residential project in Cardiff, California. The Palm residence was named the Residential Project of the Year by IB Roof Systems, the manufacturer of the PVC roof system installed on the project.

This custom home showcases spectacular ocean views and stunning architecture. Premium Roof Services replaced the 6,000-square-foot roof, which is configured in a unique shape with rounded edges. After removing two layers of old roofing, crews inspected and replaced the damaged sheathing. They then installed Securock cover board over the wood deck, followed by a 50-mil white PVC roof system from IB Roof, which was mechanically attached. The newly installed roof system was accompanied by custom copper and two-piece compression edge trim. The entire project took seven days to complete.

This beautiful estate, which has the ocean as its backdrop, posed some installation challenges, beginning with the abstract configuration of the roof. “Due to its unusual shape and scale, the estimating process needed close attention,” says Peter Codallos, president of Premium Roof Services. “The material yield/waste factor was close to 25 percent. Due to the owner’s request, we attained copper edging locally, which was different from our usual ordering process with IB. It was not a real issue but involved details we had to work though.”

“All involved on this project are extremely humbled being awarded the Residential Project of the Year,” Codallos notes. “The time and attention to detail began with estimator Angel Blas, our amazing roofing technicians, foreman Juanito Lopez, and supervised by Jose Macias. With one of the best residential warranties available that we know of, we feel confident that our client’s amazing home will be well protected with their new IB Roofing System for years to come.”

“We are proud to award Premium Roof Services the Residential Project of the Year Award,” states Jason Stanley, IB Roof Systems CEO. “The beauty and installation of the new roof is amazing. We are proud of them for their ongoing commitment to using the highest performing roofing products, offering extremely strong warranties and providing overall service to their customers and community. They are the type of roofing company that we are proud to work with.”

TEAM

Roofing Contractor: Premium Roof Services, Spring Valley, California, www.premiumroofservices.com

MATERIALS

PVC Roof System: 50-mil IB PVC, IB Roof Systems,  www.ibroof.com 

Cover Board: Securock, USG, www.usg.com

New Roof Secures Child Development Center Against New England Winters

Photos: The Garland Company, Inc.

Snow, rain and precipitation are no strangers to Bangor, Maine, where the average annual snowfall is 66 inches. For Bangor Housing Authority’s Elsie C. Coffey Child Development Center, a secure roof means safety from the wear, tear and moisture of a New England winter and protection for children both in the building and out on the adjacent playground. As maintaining a deteriorating roof and constantly replacing shingles proved costly and ineffective, Director of Construction and Asset Management Bob Rhodes and Project Coordinator Shane Vanidestine decided it was time for a more permanent solution.

The roof required a revitalization. Goals for the project included choosing the best materials to secure the roof, which features multiple hips and valleys that would demand extra attention to detail and creative installation methods.

Because the facility is a child care center, special efforts also had to be made to protect the safety and comfort of students, parents and faculty. So, in addition to the creative and meticulous efforts in creating a stunning and effective roof design, there was even more emphasis on completing the project with minimal disruption to the daily routine of the center.

The Solution

To combat the leaks and cope with the difficult roof design, contracting company Elite Roofing and Restoration combined the forces of Garland’s R-Mer Span and S-5! SnoFence. R-Mer Span metal panels were retrofitted over the existing shingles to reduce waste and prevent any debris from falling onto the playground behind the daycare. This allowed the project to be completed without any disruption to the school’s hours or play time.

Rhodes and Vanidestine knew the metal roof system was their best option, as it would provide a long life span with minimal maintenance. “The products chosen are a cost-saver for the future,” says Rhodes. R-Mer Span ensures a sleek and watertight design for the roof and is tested to protect against the most extreme weather events. For complete protection, SnoFence bars were attached directly to the metal to retain snow and allow it to melt on its own without falling off in dangerous chunks, while R-Mer Span panels keep moisture and precipitation from leaking into the building.

The unique design of the roof called for greater detail in preparation and installation. The hips and valleys of the roof design required most panels to undergo two cuts. To strengthen the seams and combat the weight of ice and snow, R-Mer Span’s I-Span clips were utilized above the valleys. Despite being a slower process, this installation was a highlight among the customers. Rhodes spoke of the preparation preceding installation: “Architects dream of making a design such as this, and we were confident leaving this to Garland and the engineering staff, despite its difficulties. After this, all of our other projects will be a breeze.”

Rhodes and Vanidestine not only understood these products to be a cost-saver for the future, but also knew that R-Mer Span and SnoFence bars would drastically improve their maintenance efforts. Now, R-Mer Span panels will keep the roof strong and watertight, SnoFence bars will alleviate the looming threat of falling snow and ice, and the community will be able to focus on enjoying the positive aspects of New England winters. As an added bonus, the striking sea mist-colored R-Mer Span panels complement the unique architecture and design of the roof.

TEAM

Contractor: Elite Roofing & Restoration, Middlefield, Connecticut, www.eliterrllc.com

MATERIALS

Metal Roof System: R-Mer Span, Garland, www.garlandco.com

Snow Retention: SnoFence, S5!, www.s-5.com

Butterfly Roof and Metal Wall Panels Highlight New Multipurpose Facility

Sevier County Utility District’s new multipurpose facility sports a butterfly roof over the main event space and two lower roof sections that cover offices, conference rooms and the kitchen. Each end of the building is open, with overhanging roofs, allowing for mountain views. Photo: Denise Retallack

The centerpiece of Sevier County Utility District’s new multipurpose facility in in Sevierville, Tennessee is a large event space that can be used by the district or rented to the public. The building also houses large conference rooms, a training room, a fitness area, administrative offices and a catering kitchen.

The design features large clerestory windows that flood the interior with natural light and a front canopy supported by steel columns. The facility’s exterior is dominated by its striking, V-shaped standing seam metal roof and metal wall panels, which are accented by brick and fiber cement siding.

“The roof was a major design element on this project from the beginning,” says A.J. Heidel, project manager for BarberMcMurry Architects in Knoxville, Tennessee. “We used the blue butterfly roof to accent the main assembly space and we used the lower roof as a wrapping element for the support spaces.”

To execute the design, it took a talented group of construction professionals including two Knoxville-based companies: Denark Construction, the general contractor on the project, and Baird and Wilson Sheetmetal Inc., the roof and wall system installer.

Crews from Baird and Wilson Sheetmetal installed approximately 13,500 square feet of Petersen’s PAC-CLAD Tite-Loc panels in Berkshire Blue on the roof. Photo: Denise Retallack

BarberMcMurry, Denark Construction, and Baird and Wilson had teamed up on other projects for the Sevier County Utility District (SCUD) in the past, so they were a perfect fit for this new construction project. The roof system chosen for the building is comprised of Petersen’s PAC-CLAD Tite-Loc panels in Berkshire Blue.

“We chose a standing seam metal roof because its material properties allow for a range of colors and ribbing patterns, and because of its ability to act as a wall cladding as well as roof,” notes Heidel. “We were able to give different characteristics to separate volumes by changing from blue smooth flat lock panels to Musket Gray ribbed panels while maintaining a similar method of installation.”

The design team originally explored using insulated metal panels for the roof and walls. “We were asked by Denark Construction to price this project,” says Jim Galbraith, vice president of Baird and Wilson. “I priced the insulated roof and wall panels and Denark came back asking if there were potential savings through value engineering. We submitted pricing for single-skin roof and wall panels and it was accepted.”

To make sure everyone was on the same page, pre-construction meetings involving the architect, general contractor and roof system installer included a mock-up of the panel system. “We had a mock wall with all of the roofing and wall conditions, and we met with them on site to go over all of the details,” explains Heidel.

The Installation

Baird and Wilson installed approximately 13,500 square feet of Tite-Loc roof panels on the roof, as well as 3,500 square feet of 16-inch Snap-Clad standing seam wall panels. “We also fabricated and installed gutter, downspouts, horizontal flush wall panels, low and high soffit, and fascia,” notes Galbraith.

After the metal deck topped with a nail base, insulation, and ice and water shield, the roof panels were installed and mechanically seamed. “The slope was less than 3:12, so the Tite-Loc panel was a perfect fit,” Galbraith says.

The exterior of the is features a mix of materials, including seamed metal wall panels, flush wall panels, fiber cement siding and brick accents. Photo: Matt Horton, hortonphotoinc.com

Work began on the butterfly roof. The valley features an internal gutter, which drains through downspouts that penetrate through the soffit and go down the front of the building, where they drain through underground pipes. “At the entrance we installed some horizontal blue flush panels that matched the roof,” notes Galbraith. “We also installed the fascia and soffit in Berkshire Blue, which matched the roofs on other buildings on the campus, which were also that color.”

The roof-to-wall transition was designed to make it appear the roof was wrapping around the building. “The roof panels were 16 inches on center, and the wall panels were 16 inches on center,” Galbraith explains. “The seams on the wall panels and the roof panels had to line up perfectly all the way down, so that was a bit tricky. You had to pay attention and do the math as you were going down to make it all work.”

Challenging Site

The limited area surrounding the building proved to be a major challenge on the project. “The building itself takes up much of the buildable area, leaving little room for things like parking and site drainage,” says Heidel. “We were able to avoid a water detention pond by using rain gardens on the site.”

The rain gardens are located against the main road, with parking spaces designed to shed water to that area, which includes native plants that thrive in a wet habitat. The pipes from the building’s downspouts flow there as well.

Tennessee’s spring weather was also a concern. “Construction took place in early spring, and the wind was whipping,” says Galbraith. “It was also rainy, and there was a corner where water would sit, so we had to be careful moving our lifts so they didn’t get stuck in the mud. The most difficult problem was manhandling the long roof panels. Many were more than 50 feet long.”

Photo: Matt Horton, hortonphotoinc.com

Despite the challenges, the project went smoothly. “BarberMcMurry prioritizes long-term client relationships, and this project is a great example of that,” Heidel says. “We have a history of successful projects with SCUD, and we continued that pattern through this project, which was delivered on time and on budget.”

“We work with our clients on designs that fit their brand, reflect their use, and are fully functional as well as beautiful,” Heidel continues. “That outlook is reflected in this project, too, through the overall design of the spaces and our creative use of materials. Finally, BMA is committed to sustainability and stewardship through design. In this project with SCUD, you can see sustainable design elements in the rain gardens, which filter and control the release of storm water as it leaves the site, and in the building’s clerestory windows and shaded curtain wall, which take advantage of daylighting.”

The project also showcases the quality workmanship of Baird and Wilson. Galbraith cited a quote from Charles R. Swindoll that serves as a company motto: “The difference between something good and something great is attention to detail.”

TEAM

Architect: BarberMcMurry Architects, Knoxville, Tennessee, www.bma1915.com

General Contractor: Denark Construction, Knoxville, Tennessee, www.denark.com

Roofing Contractor: Baird and Wilson Sheetmetal Inc., Knoxville, Tennessee, www.bairdandwilson.com

MATERIALS

Roof Panels: PAC-CLAD 24-gaugeTite-Loc panels in Berkshire Blue, Petersen, www.PAC-CLAD.com

Wall Panels: PAC-CLAD 24-gaugeSnap-Clad panels in Musket Gray

New Synthetic Slate Roof Tops Historic Owatonna City Hall

The city offices in Owatonna, Minnesota, are housed in a historic building that underwent a complete roof replacement as part of an ambitious restoration plan. Photo: Lakeshore Drone Services

The massive brick complex in Owatonna, Minnesota, that currently serves as its city hall has an interesting past. According to Aaron Fitzloff, facility manager for the City of Owatonna, the structure was originally built in 1886 as the Minnesota Public School for Dependent and Neglected Children. The facility closed in 1945 and later became the Owatonna State School. “The state closed it in 1970, and the city of Owatonna took it over in 1974,” notes Fitzloff. “In 1975, the building was listed on the National Register of Historic Places.”

The complex now houses administrative offices for the city and the Minnesota State Public School Orphanage Museum. Asphalt shingles had been installed on the roof at some point in the 1990s, but leaks developed over the years, and the city budgeted for a complete roof replacement as part of an ambitious restoration plan. “The intent was to get the building back to its original state,” says Fitzloff.

Specifying a New Roof

The city consulted with Adsit Architecture and Planning, a full service architectural and interior design firm located in Minneapolis. When the firm completed a condition assessment for another historic building in Owatonna— the Firemen’s Hall —that project led to a request from Fitzloff to look at the city’s administration building.

Crews from Schwickert’s Tecta America installed more than 29,000 square feet of DaVinci synthetic slate. Photo: Lakeshore Drone Services

“Aaron realized that all of the roof systems were in need of replacement at this point,” says Gunstad. “He wanted to make sure, first and foremost, that we mitigated any moisture problems that were occurring up in the attic space. The project was about insulation as well as roofing.”

Finding the right roof system was crucial. Evidence suggested that the original roof was comprised of slate, but that couldn’t be confirmed due to a fire that had destroyed the main building in 1904. “Even before we did our research, we knew from our first look at the building that an asphalt roof on a building of this mass and scale did not look right,” Gunstad says.

Adsit Architecture specified a synthetic slate roof system manufactured by DaVinci Roofscapes. “Right off the bat we felt that given the scale of the building that slate would have been prohibitively expensive for them, and they agreed,” Gunstad recalls. “We knew with the cost, ease of installation, the warranty, the weight — all of that — the synthetic slate would be a really good fit, and DaVinci had an enormous amount of color choices for the blends we needed.”

DaVinci’s Color Visualizer Tool was used to help determine the colors. A European blend of gray shades and purple was installed. As the project got under way, the hunch that the original roof was slate was confirmed. “When we got into reconstruction and were up digging around in the attic, we did find some old slate pieces,” Gunstad recalls. “Oddly enough, they were a perfect match for the colors we had chosen.”

Installing the Roof Systems

The installer on the project was Schwickert’s Tecta America, headquartered in Mankato, Minnesota. “We ended up being the only bidder on it, which of course you don’t know at the time,” notes Scott Haefner, Schwickert’s steep slope project manager.

The scope of work on the project included 60-mil Carlisle EPDM, new gutters and custom-fabricated metal trim. Photo: DaVinci Roofscapes

According to Haefner, the difficulty of the project is what made it appealing for the company, which thrives on projects others turn away from. “Those are the ones we look for — the ones that have some complexity to it,” says Haefner. “That’s where we can shine. We have our own metal shop, we can do all our own metal fabrication, and we can do the types of things that can really set us apart. It gives us an advantage because we don’t have to farm some of that work out, and we have complete control over the whole process.”

The scope of work included installing more than 29,000 square feet of the DaVinci synthetic slate. The roof also included low-slope areas, and for these a 60-mil EPDM from Carlisle was installed. Sheet metal work included new gutters and custom-fabricated metal trim.

The safety plan was crucial, as the building would be open during the construction process. “You start with the safety plan,” says Haefner. “With staff and members of the public walking in and out, it is critically important in your pre-construction meetings to address those issues with overhead protection in certain areas, and blocking off certain areas when you’re working above them for the day.”

The safety plan incorporated scaffolding and personal fall arrest systems, as well as overhead protection for pedestrians. Photo: Schwickert’s Tecta America

Coordination with the city staff was critical. “Aaron Fitzloff helped us tremendously in that area,” says Haefner. “We had a standing meeting every Tuesday morning at 9, and that was always a big part of the conversation — safety and the sequence of what we were going to do that day. Aaron and I would also see each other every day also, typically. He was a great attribute to the whole project, for sure.”

Safety equipment included scaffolding and PFAS. “The vast majority of the building was scaffolded,” Haener says. “Fall arrest was anchored to the roof in areas we didn’t have scaffolding, and even where we did, the roof pitch was steep enough that everyone was always tied off with anchors and fall arrest systems.”

Work began in the late fall and progressed in sections. “That’s part of the beauty and charm of the building — its different additions and roof sections,” notes Haefner. “That also allowed us to focus on one area at a time. That’s typically what you do — you start and do a section that’s kind of an easy one to just get your feet underneath you and get a feel for how it’s going to go. There were some big, long planes of roof that we were able to get a start on and get a feel for the whole sequence.”

Schwickert’s steep-slope division handled the composite slate roof installation, while its flat roof division tackled the EPDM roofs.

Tying in flat and steep-slope roof systems was critical. Steep slope-crews completed most of their work first, using a Grace Ice & Water Shield product that is compatible with EPDM. “Let’s say you know the EPDM is going to go let’s say two feet up the slope of the roof, from flat to transition up the steep slope,” Haefner explains. “We’d leave off the bottom two or four courses of shingles, and leave the ice and water shield exposed, but not adhered.”

Photo: DaVinci Roofscapes

Low-slope crew members would just flip up the ice and water shield and install the EPDM. Steep-slope crews would then install the metal flashing, adhere the ice and water shield, and add the final courses of shingles.

A snow retention system from Rocky Mountain Snow Guards was installed in several sections of the roof.

Re-roofing the large turret was made easier by DaVinci’s turret package, which supplies pre-cut tiles. “You give them some basic information, including the circumference and the pitch,” Haefner says.

It worked well on the project, with one minor hitch that was quickly remedied. “This one was a little different because it has a sort of witch’s hat appearance to it, where the pitch changes at the bottom,” Haefner says. “It’s not a typical cone shape. When I sent in the request for the package, I didn’t take that into account, and we needed to order some more shingles to finish the turret.”

The large finial on the turret was taken down, painted and replaced.

A heat mesh system was installed in certain areas that had been subject to ice dams in the past. The Warmquest Zmesh system consists of woven copper mesh, which was installed below the tile, sandwiched between layers of ice and water shield. “That was a tricky part of the installation,” says Haefner. “We had to run big transformers, electrical panels, and run conduit to these areas from the old attic.”

The Minnesota weather brought things to a halt in the mid-winter, and work concluded this spring.

Mission Accomplished

Haefner points to this project as proof of his company’s ability to complete projects with multiple scopes of work. “With steep slope, flat roof, sheet metal work, new gutters, insulation, and the electrical portion involved with installing the heat mesh system — it shows perfectly how we can install multiple complex systems that have to go together in a certain way,” he says. “That type of complexity is where we shine.”

The city and its residents have been pleased with the result, according to Fitzloff. “Feedback has been nothing but positive,” he says. “We cleaned all of the limestone around the whole building as well, and it looks fabulous.”

Gunstad notes that the project fulfilled its design goals: making the building sound and restoring it to its former glory. “Performance and maintenance of the project were our primary concerns, but design-wise, looking at this building, which is rather grand, we knew it lacked something — and that something was a substantial roof,” says Gunstad. “We wanted to give that visual prominence back to that building, which is a hallmark of the city.”

TEAM

Architect: Adsit Architecture and Planning, Minneapolis, Minnesota, www.adsitap.com

Roofing Contractor: Schwickert’s Tecta America, Mankato, Minnesota, www.schwickerts.com

MATERIALS

Synthetic Slate: Single-Width Slate, DaVinci Roofscapes, www.davinciroofscapes.com

Low-Slope Roof: Carlisle 60-mil EPDM

Leak Barrier: Grace Ice & Water Shield

Underlayment: Titanium UDL

Snow Retention: Rocky Mountain Snow Guards

Community Center Sparkles With New Metal Roof

The community center was re-roofed using a structural sub-framing system from Roof Hugger that allowed the existing metal roofing to remain in place while the new roof system was installed above it. Photos: Roof Hugger, LLC

Just down the road from Pigeon Forge, Gallatin, Dollywood and other popular attractions in the Smokie Mountains is the thriving community of Sevierville, Tennessee. This beautiful mountain town has a community center and a civic center that hosts multiple events throughout the year. The community center is housed in a 1985 vintage metal building manufactured by American Buildings. Due to its age, the building recently underwent a complete re-roofing with metal in a process commonly known as a metal-over-metal retrofit. The building was originally constructed using American’s trapezoidal standing seam profile, so the decision was made to utilize a structural sub-framing system furnished by Roof Hugger, LLC. This type of retrofit allows the existing metal roofing to remain in place. The structural sub-framing is installed over the existing roof and then a new metal roof system is installed, which becomes the finished weathering surface.

The local community leaders were not new to this type of re-roofing for aged metal roofs because of their experience with a 2017 project at Lanier Elementary School in nearby Maryville. This project was designed by Chuck Howard of Metal Roof Consultants (MRC) from Cary, North Carolina, the same company selected for the community center re-roof. MRC has years of experience with retrofit roofing of existing metal roofs, as well flat roofs that receive an engineered light-gauge steel framing system to create a sloped roof plane. On the community center project, MRC consulted with Doyle E. Jones of Sevierville, the architect and roof consultant on the Lanier Elementary project.

Morristown Roofing was awarded the community center project through a public bid process in early 2019. Founded in 1962 by the late Paul Horner, Morristown Roofing now has a footprint of quality roofs in six states throughout the Southeast. With an overall staff of about 55 employees, the company installs all types of roofing from single-ply membranes to metal. The company’s motto: “No project is too large, nor too small for Morristown Roofing.”

According to Ashley Horner of Morristown Roofing, this project was only the company’s second Roof Hugger installation. The job went smoothly, even with the building’s roof geometry having had sloped rakes, varying slopes, multiple valleys and other difficult transitions. Horner went on to say the Roof Hugger product has the ability to increase snow loading and has little to no impact on the occupants of the building. It also helps control the contractor’s liability by eliminating the need to remove the existing metal roof. In addition, with existing trapezoidal metal roofs that are notorious for varying center-to-center major rib spacing, the Roof Hugger sub-purlin design compensates for this issue. Factory oversize notching of the Z-shaped sub-purlin’s vertical web permits easy installation directly over the existing roof panel high ribs, allowing for base flange attachment into the existing purlins. The result is a structurally correct, low-profile, finished retrofit framing assembly ready to receive the new metal roof panels.

The project finished out with 54,000 square feet of 24-gauge  System 2500 metal roofing by MRS Metal Roofing Systems, Inc. Approximately 12,720 linear feet of Roof Hugger’s standard Model “D” sub-purlin with a 4.5-inch web height was installed. The new roof included a ColorGard snow retention system manufactured by S-5!

TEAM

Consultant: Metal Roof Consultants (MRC), Cary, North Carolina, www.metalroofconsultants.net

Roofing Contractor: Morristown Roofing, Whitesburg, Tennessee, www.morristownroofing.net

MATERIALS

Structural Sub-Framing: Roof Hugger, LLC, www.roofhugger.com

Metal Roof: System 2500, MRS Metal Roofing Systems Inc.,  www.metalroofingsystems.biz

Snow Retention: ColorGard, S-5!, www.S-5.com

Re-Roof of Busy Post Office Facility Becomes Award-Winning Project

Crews from Roofing Solutions replaced the 300,000-square-foot roof on the United States Post Office General Mail Facility in Baton Rouge, Louisiana. Photos: Sam Barnes

The United States Post Office General Mail Facility in Baton Rouge, Louisiana, manages mail for the entire Greater Baton Rouge area. When the roof on the 300,000-square-foot building was nearing the end of its useful life, it was clear the roof replacement project would pose some big challenges. It was a given that the new roof system must prove durable and reliable to protect the mail delivery system that businesses and individuals rely on every day. It was also critical that the re-roofing work would not interfere with mail processing at the facility, which operates around the clock.

Architect Crump Wilson and Wharry Engineering specified an asphalt roofing system for the project — a two-ply modified bitumen system manufactured by SOPREMA. All parties agreed that asphalt was the best roofing solution for the facility due to its longevity, durability, and long-term dependability.

Roofing Solutions, LLC, headquartered in Prairieville, Louisiana, was invited to bid on the project. “We were the successful low bidder,” says Tupac de la Cruz, the company’s founder and operations manager. “When we started working on the planning and phasing, we realized the job was going to be an undertaking because, number one, it was a big-size job, and number two, the facility works 24-7.”

Completing the project without interrupting operations would be the biggest challenge on the project. Crews could not interfere with traffic flow and mail deliveries, and would have to protect people and sensitive machinery inside.

“Before beginning the re-roof project, we were given a full tour of the facility,” de la Cruz says. “It was an eye-opening experience to see the equipment, systems, and personnel that manage the mail delivery process from start to finish. You had to coordinate with the facility manager, the transportation manager, and multiple stakeholders to make sure that you did not interrupt all of the conveyor lines sorting all of the mail coming in and out of that facility every day.”

Working in Sections

The deck was exposed to the interior, increasing the risk of dust falling onto the equipment, so Roofing Solutions crews installed a 6-mm protective film using a Spyder lift. “We installed special sheathing underneath the deck to protect the conveyor systems and all of the equipment,” noted de la Cruz. “We also had to protect the workers and make sure that there was no noise, no dust, or any disruptions from anything to do with the roof replacement.”

Sunbelt Vacuum Service was contracted to remove the rooftop gravel. Then the old built-up plies were then cut up and removed by hand. “We had a metal deck, and we couldn’t put any heavy equipment on it,” de la Cruz recalls.

Work proceeded in sections to ensure everything remained watertight. “You had to cover everything you’d demo the same day,” de la Cruz says. “In the summertime in Louisiana, it can rain almost every afternoon.”

The new roof system included two layers of mechanically attached polyiso insulation, which was topped with SOPRABOARD, an asphaltic cover board, which was adhered with COLPLY adhesive. The two ply system was comprised of a base play and a cap sheet Designers chose SOPREMA’s Solar Granule cap sheet membrane, which provides the benefit of high reflectivity. Torches were not allowed on the project, so the membrane was set in cold adhesive. “Because we could not use any torches, all of the laps for modified bitumen cap had to be sheet welded with a robot like you were doing single-ply,” notes de la Cruz.

The roof system specified for the project was a two-ply modified bitumen system topped with SOPREMA’s Solar Granule cap sheet membrane.

Most of the roof area was clear sailing, but access at the jobsite was limited due to the busy transportation routes. “It was a nice, wide roof,” says del la Cruz. “The hardest part was getting the material from one end of the roof to the other, because we only had access at one point. No motorized vehicles were allowed up there, but we were able to use carts to move material from one end to the other.”

The roof features four large raised sections framed with clerestory windows, and the multiple levels sometimes made moving material difficult. “In some cases, you had to bring the material across one level, bring it up to another level and back down again,” says de la Cruz.

The existing skylights were replaced with new single-slope skylights manufactured by KalWall.

Safety and Security

The safety plan utilized mix of guardrails, perimeter flagging, and safety monitors, depending on the configuration of each section. “We also had to have a flagging man on the bottom to make sure we were not interfering with the 18-wheelers coming in and out with their packages,” de la Cruz says. “The project extended over Thanksgiving and Christmas, and you couldn’t imagine the amount of trucking that goes through that facility during Christmas.”

Making sure everyone was on the same page was crucial. Weekly planning meetings were supplemented with daily huddles. “We met with the facility manager every morning to make sure we let him know where we’d be and what we were going to do that day,” de la Cruz explains, “Every afternoon, we’d let him know what the plan for the next day was so they could plan ahead. It was a very proactive approach.”

The crew, which included 20 men during the peak of the project, usually accomplished 3,000 to 3,500 square feet of demo and roof replacement per day. The project was completed in seven months — three months ahead of schedule.

The project was recognized by the Asphalt Roofing Manufacturers Association as the Silver Award winner in the 2020 ARMA Excellence In Asphalt Roofing Awards program, which recognizes industry professionals for their high-performing steep-slope and low-slope asphalt roofing projects across North America.

“We had such pride in completing that project because it was so large and we had zero injuries, no issues, and the client was very happy. We decided to submit it, and we got the award,” says de la Cruz.

“We finished the project about three months ahead of schedule, and we were able to complete the job with no interruptions to the facility. We knew if we could do that, in the end it would be a successful project.”

For more information about submitting a project for the Excellence in Asphalt Roofing Awards, visit www.asphaltroofing.org.

TEAM

Architect: Crump Wilson, Baton Rouge, Louisiana, www.crumpwilsonarchitects.com

Roof Consultant: Wharry Engineering, Garland, Texas, www.wharry.com

Roofing Contractor: Roofing Solutions LLC, Prairieville, Louisiana, www.roofingsolutionsla.com

MATERIALS

Membrane: SG Solar Granule Cap Sheet, SOPREMA, www.soprema.us

Cover Board: SOPRABOARD, SOPREMA

Skylights: Kalwall, www.kalwall.com

Acoustical Smoke Vents Are Key Priority for School’s Theater Renovation

The renovation included the construction of a new visual arts wing that integrates a rich cross-section of artistic disciplines with a gallery, studio and classroom spaces. Photos: Sarah Hamlin/Everchangingphoto

Roofing experts are well aware smoke vents can save lives and reduce the amount of property loss. While life and property safety are their primary function, acoustical smoke vents also play an important part in noise mitigation. When Middlesex School in Massachusetts renovated the 55,000-square-foot Bass Pavilion for the Arts and Danoff Visual Arts Center, the architectural team from CBT Architects selected four acoustical smoke vents manufactured by The BILCO Company.

“The features that were included in the smoke vents were geared to student safety,” says Michelle Oishi, the lead architect on the project for CBT. “That was of paramount importance. They were also space considerations, and the automated aspect of the vents was important due to the fact that we wanted very few things interfering with the rigging sets.”

Broad Scope

The primary objective of the project aimed at improving the existing theater and creating a space where the school’s entire 400-plus students and nearly 100 faculty members could assemble. The previous structure was built in the 1960s. The school opened in 1901.

“There’s a commitment to theater and the arts,” says Steve McKeown, the school’s project manager. “It’s not any different than our commitment to clubs, sciences or athletics. We provide spaces for students who are interested in a variety of things. There’s a lot of cool opportunities for students to find their promise.”

Middlesex School recently completed an extensive renovation project of the school theater. The project included six double-leaf acoustical smoke vents manufactured by The BILCO Company.

Architects, engineers and contractors needed a large dose of creativity to execute the project. The theater’s original roof structure and perimeter walls needed to remain standing. In essence, the renovation was a major do-over of the existing space without adding additional square footage. “We had to work within the confines of the existing roof structure and the surrounding walls,” Oishi said. “A certain amount of the existing building was out of character with the rest of the school.”

The acoustical smoke vents used in the Middlesex School renovation are 6-foot-by-6-foot double-leaf smoke vents with motorized operation that allows them to be opened and closed from a remote location. They also include limit switches, which allow for monitoring if the vents are in the open or closed position.

Automatic smoke vents protect property and aid firefighters in bringing a fire under control by removing smoke, heat and gases from a burning building. This ensures better visibility, evacuation time, and protection against fire spread, as well as reduced risk of smoke inhalation and structural damage. They are activated upon the melting of a fusible link, and are ideally suited for large expanses of unobstructed space such as factories, warehouses, auditoriums and retail facilities.

Acoustical smoke vents, however, take on the added quality of controlling noise. They are used in theaters, concert halls and other projects where it is important to limit noise intrusion.

Know Your Ratings

Acoustical smoke vents and their ability to block out noise are determined by ratings in Sound Transmission Class and Outdoor-Indoor Transmission Class. For acoustical smoke vents, the OITC rating is the more important figure for architects to consider.

OITC rates the transmission sound between outdoor spaces and indoor spaces in a structure. Like the STC rating, OITC measures sound intensity loss in decibels. The OITC rating was developed in 1990 and is typically used to measure sound transmission loss over a frequency range from 80 to 4000 hertz. It is most applicable for measuring the prevention of low frequency exterior sounds such as automotive traffic, construction, and low-flying airplanes through exterior building surfaces.

STC measures the extent to which sound is prevented from being transferred from one area to another. The higher the STC value, the less that sound can be transferred through a building product. STC is typically used to measure sound transmission loss over a frequency range from 125 to 4,000 hertz and is most applicable for interior areas that experience mid to high frequency noises, such as conversation, television, telephones, and office equipment.

“OITC is the preferred rating when addressing sound insulation from exterior noise — especially when transportation noise sources are impacting a building facade with significant low-frequency (bass) sound,” says Harold Merck, principal and acoustician for Merck & Hill Consultants of Atlanta. “While STC ratings may be fine for typical interior noise sources such as voices, STC doesn’t adequately address the extended low-frequency noise contribution of aircraft, traffic or even large roof-top equipment. The OITC better addresses low-frequency noise impacts and is the more applicable sound rating for roof mounted automatic smoke vents.”

The BILCO Company recently unveiled a new acoustical smoke vent, with an STC rating of 50 and an OITC rating of 46, that provides the highest level of protection against exterior noise intrusion. In addition, the product has also received an ISO-140-18 sound rating when tested against rainfall sound. The rating measures the impact of sound insulation on building materials — such as roofs, skylights and roof/ceiling systems — incur when exposed to artificial rainfall.

Checking All the Boxes

From the roof on down, the completed project at Middlesex checks all of the boxes that were the target of the two-year renovation.

The main stage now includes balcony seating that allows the entire student body and faculty to fit comfortably as an audience for performances, guest speakers and all-school assemblies. It features a motorized orchestra pit that can be raised up to the stage level.

There are gallery space and pin-up areas as new arenas to celebrate and encourage the artistic pursuits of students. There is also a new “mindfulness” space that will provide “emotional and intellectual space to reflect and recharge,” according to the architect. Workers also improved a courtyard to provide accessible entry to adjacent buildings which includes a terrace that serves as an exterior performance venue.

Thanks to the acoustical smoke vents, it also includes important life and property safety features that also limit exterior noise.

“It’s an awesome space,” McKeown said. “The entire community gathers there on a weekly basis, and it’s very comfortable. It provides a space where our community can gather, and that’s something that is very important to our school.”

About the author: Thomas Renner writes on building, construction, and other trade industry topics for publications in the United States.

TEAM

Architect: CBT Architects, Boston, Massachusetts, www.cbtarchitects.com

Contractor: J.S. Mortimer Inc., Auburn, Massachusetts, www.jsmortimer.com

MATERIALS

Smoke Vents: Acoustical Smoke Vents, The BILCO Company, www.bilco.com

Shingles: Landmark, CertainTeed, www.certainteed.com

State-of-the-Art Wall System Protects New Gymnasium Complex

The new $6 million gymnasium complex at Pacific Christian School features Enerfoil Wall Insulation and the AquaBarrier AVB System from IKO. Photos: IKO

A state-of-the-art $6 million gymnasium for Pacific Christian School in Victoria, British Columbia, replaced the school’s existing facility, constructed nearly 40 years earlier.

The new facility created a double-sized gymnasium with a mezzanine, changing and locker rooms, and a commercial kitchen. The school has 900 students enrolled from preschool to grade 12.

The Pacific Christian School project demanded a wall system that would perform well with the wet weather conditions of the Pacific Northwest. Since school was in session during the project, a fixed timeline was imperative. Brytar Contracting worked around the school’s daily routine, and certain parts of the school were off limits, with only one door accessible to construction staff.

For the building’s walls, Brytar Contracting proposed IKO’s Enerfoil system because of its superior R-Value and ease of installation. According to Brytar Contracting Business Development Manager Les Starling, the company full service general contracting company that specializes in wall panels. “Our work includes lots of multi-family and high rise projects, so we were looking for an alternative to a rigid wall solution for this project,” he says.

In all, approximately 8,640 square feet of wall systems were installed on the project, which qualified for an IKO AquaBarrier Waterproofing Material Warranty. “While we used AquaBarrier AVB on another school project, this was Brytar’s first time to install the IKO Enerfoil insulation product,” notes Starling. “Both are outstanding products and performed perfectly. As we see it, all-insulated wall systems are the way of the future.”

This was the first significant project supplied by Roofmart in Victoria using IKO Enerfoil and IKO AquaBarrier AVB, according to Rob Strickland, Regional Manager, Roofmart Vancouver Island.

TEAM

Architect: HDR, Vancouver, British Columbia, www.hdrinc.com

General Contractor: Kinetic Construction Ltd., Victoria, British Columbia,www.kineticconstruction.com

Wall Contractor: Brytar Contracting, Vancouver, British Columbia www.brytarcontracting.com

Distributor: Roofmart, Vancouver, British Columbia, www.roofmart.ca

MATERIALS

Wall System: Enerfoil Wall Insulation and AquaBarrier AVB System, IKO, www.iko.com

Ford Plant Transformed into Museum and Hotel Is Crowned by Rooftop Deck

Built on the site of a Ford assembly plant, the 21c Museum Hotel in Oklahoma City is crowned by a rooftop deck that provides access to the plant’s original water tower. Photo: Mike Schwartz

The 21c Museum Hotel in Oklahoma City encompasses a contemporary art museum, a 135-room boutique hotel, event spaces, and Mary Eddies Kitchen x Lounge. It also features a rooftop deck with stunning views of the city.

The hotel was built at the site of an idle Ford Motor Company assembly plant originally designed by Albert Kahn. The building was refurbished to serve as the hotel and museum in the first phase of an ambitious development project. The Ford plant’s original water tower was retained during the renovation, and it is accessible via a catwalk from the rooftop deck, which also frames a green roof area.

The deck’s 1,500-square foot wood paver system was manufactured by Bison Innovative Products and installed by Elevated Paver Systems (EPS), headquartered in Oklahoma City.

According to Adam Fink, president of EPS, the company was founded in 2011 to serve the pedestal-set rooftop paver market in Oklahoma. The company specializes in difficult hardscape projects including rooftop pavers, pavers at grade, and architectural stone, including cut-to-size marble and granite. EPS was tapped for the deck installation by Lingo Construction, the general contractor on the project.

“It is a really unique venue and it was a unique construction project,” Fink says.

The building is crowned by its rooftop deck, which is comprised of 2-foot-by-2-foot, eight-plank Ipe Wood Tiles set on Bison Versadjust Pedestals. The pedestals were installed atop steel I-beams that were erected above the newly refurbished roof, which features a 60-mil PVC roof system manufactured by Johns Manville. The beams were installed along with the catwalk and an integrated railing system.

“This was a unique project for us because we are usually installing our systems right on top of the roof membrane,” Fink says. “Here we had a newly installed steel substrate that our pedestals rested on.”

Proper placement of the beams was crucial. “The flat part of the beam was pretty narrow, all things considered, so the biggest challenge in the whole scenario was to make sure that the steel was exactly right,” notes Fink.

The steel beams had to be at the correct elevation and proper spacing throughout their length, with a tolerance of plus or minus a quarter inch. According to Fink, the key to success was communication between the design and installation teams. “We worked carefully on the shop drawings and dictated the on center spacing,” Fink recalls. “Little things that usually don’t matter very much were critical here because the tolerances were so tight. The steel subcontractor did an excellent job.”

The pedestals were adhered to the beams using Dow Corning 795 silicone sealant, and the wood tiles were then locked into place. Crews used an automatic laser to make sure the tiles were level, using shims in areas where the steel beams were slightly off.

The green roof was also supported by a steel substructure. Since the roof framed the rectangular garden area, coordination was crucial here as well. The goal was to ensure that the tiles fit optimally. “We coordinated the shop drawings to make sure we didn’t have any small pieces,” notes Fink.

Safety concerns were minimal, as the area was surrounded by a large parapet wall and railings, and material could be brought to the roof by the freight elevator. The biggest concern for EPS crews was the trip hazard posed by the steel beams. “It was kind of like working above a kids’ jungle gym,” says Fink. “But it’s nothing we couldn’t cover in our toolbox talks.”

The deck installation went smoothly, and Fink credits detailed planning for the successful outcome. “Coordination was the key,” he says, noting that precise shop drawings and pre-engineering meetings were the most crucial elements of the project. “Once the steel was in place, we just took out field measurements and went at it from there,” he says. “It was all a downhill slide after that.”

Fink points to in-house drafting capabilities as a key strength of EPS. “We pride ourselves on our pre-construction submittals,” he says. “This job went really well. There weren’t any glitches because we prepared a very good plan and executed it.”

TEAM

Architect: Deborah Berke Partners, New York, www.dberke.com and Hornbeek Blatt Associates, Edmond, Oklahoma, www.hornbeekblatt.com

General Contractor: Lingo Construction Services Inc., Oklahoma City, Oklahoma, www.buildwithlingo.com

Roofing Contractor: Coates Roofing Company Inc., Seminole, Oklahoma, www.coatesroofing.com

Roof Deck Installer: Elevated Paver Systems (EPS), Oklahoma City, Oklahoma, www.okeps.com

MATERIALS

Pavers: Ipe Wood Tiles, Bison Innovative Products, www.bisonip.com

Pedestal System: Versadjust Pedestals, Bison Innovative Products

Roofing Membrane: 60-mil PVC,Johns Manville, www.JM.com