A Trade Association Brings Roofs to the Sustainability Discussion

Roofs, first and foremost, keep water and the elements out of a building. The roofing industry has done this quite well since the modernization of buildings began more than a century ago. Along the way, a number of trade associations—ARMA, ERA, MCA, NRCA, PIMA, SPFA, SPRI—have formed and evolved as materials and trends have changed. Each group provides excellent information relative to its mission and goals. Yet we know change keeps coming.

THE BYRON WHITE COURTHOUSE, DENVER, features a RoofPoint-certified high R-value (R-30) roof for energy savings. A dual-reinforced Derbigum modified bitumen membrane, 90-mil base sheet and a high-density coverboard were installed.

THE BYRON WHITE COURTHOUSE, DENVER, features a RoofPoint-certified high R-value (R-30) roof for energy savings. A dual-reinforced Derbigum modified bitumen membrane, 90-mil base sheet and a high-density coverboard were installed.

Since the turn of the century, the awareness and push for energy efficiency of buildings and the sustainability for materials and building design has grown substantially and has become an important topic in the public forum. Sustainability and environmentalism are universal topics.

Serving as a unified voice for issues involving roofing, energy and the environment, the Center for Environmental Innovation in Roofing was established in Washington, D.C., in 2008. The non-profit organization’s focus is to advocate and promote the use of environmentally friendly, high-performance roof systems, not just within the U.S., but in North America and globally. The center is a member-based association consisting of roofing manufacturers, roofing contractors, roofing consultants, raw-material suppliers and other trade groups within the roofing industry.

To promote the sustainability of roof systems, the center develops resources, products and educational information that can be used by the building industry to advance the longevity, durability and overall sustainability of roofs. Increased awareness of the importance of a building’s roof is critical to the center’s mission. The roof can be a large contributor to the energy efficiency of the building, a long-term asset and, increasingly, a location for energy production (solar, wind).

ROOFPOINT

The center’s premier program is RoofPoint, a guideline for environmentally innovative nonresidential roofing. RoofPoint is used to evaluate new and replacement roofs for commercial and institutional buildings based on their environmental performance during the life cycle of the building the roof covers. This provides a useful measure for what constitutes a sustainable roof during design, construction, operation and decommissioning.

RoofPoint is primarily a rating system, and when certain minimums are met, a roof can become a RoofPoint Certified roof. Certificates and plaques noting RoofPoint certification can be awarded and used to validate a commitment to sustainability and the environment.

RoofPoint is based on current state-of-the-art processes and methods, remaining technology neutral. It does not rank or prioritize materials or systems; however, RoofPoint emphasizes energy efficiency and long-term performance and durability as overarching key attributes of a sustainable roof. Material recycling and reuse, VOCs, water capture and reuse, hygro-thermal analysis, and operations and maintenance are a few of the categories within RoofPoint.

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Roof Decks: Don’t Underestimate the Backbone of the Roof System

NOTE: This article is intended to provide general information while conveying the importance of the roof deck as an integral part of a roof system. Additional information about specific effects and concerns in regard to roofing can be found in The NRCA Roofing and Waterproofing Manual and various roof-cover manufacturers’ design guides.

Wood plank decks can provide a dramatic exposed roof deck.

Wood plank decks can provide a dramatic exposed roof deck.

The roof deck is the backbone and an integral component of all roofing systems. Its main function is to provide structural support for the roof system and, therefore, is a building element that needs to be designed by a licensed design professional because proper support of the roofing above is critical to the roof system’s success.

Roof decks also add thermal performance and fire resistance and ratings, provide slope for drainage and enhance wind-uplift performance. They must accommodate building movement and often determine the attachment method of the vapor retarder, insulation and membrane.

Roof Deck Types

There are many types of roof decks being installed today:

  • Steel
  • Precast concrete panel
  • Structural concrete
  • Cementitious wood fiber
  • Wood planking
  • Plywood/OSB
  • Poured gypsum

Some decks are covered with topping fills that become the base for the roof system and may also be an integral structural component:

  • Concrete
  • Lightweight insulation concrete topping
  • Lightweight aggregate concrete topping

Other deck toppings are available, such as poured gypsum and lightweight concrete with integral insulation, but these are considered substrate covers and not roof decks.

The most prevalent roof deck in the U.S. for commercial buildings is steel. On the West Coast, plywood/OSB is very popular. In addition to the roof decks already mentioned, in the course of roof-replacement work the designer may come in contact with the following:

While the “plate” test is not a preferred method, it can quickly and inexpensively give an indication of retained moisture in lightweight aggregate concrete roof deck covers.

While the “plate” test is not a preferred method, it can quickly and inexpensively
give an indication of retained moisture in lightweight aggregate
concrete roof deck covers.

  • Book tile
  • Lightweight precast concrete planks
  • Precast gypsum planks
  • Transite

Collaboration with the Structural Engineer

Because a roof deck is the foundation for the roof system, the designer needs to coordinate the roof system design requirements for the roof deck with the structural engineer to ensure the performance of the roof system. For example, the roof deck may need to extend to the roof edge. In this example, the roof deck may not need to extend to the roof edge for structural concerns but is needed to support the roof system; the roof designer must address this. If the roof deck is structurally sloped, the designer and engineer must determine whether the low point is a potential drain location. Are there steel beams in the way of the drain location? The roof deck must be attached to the structure to prevent uplift. And the designer and engineer must determine what the deflection of the roof-deck span may be between structural supports. For example, steel deck is sometimes installed with spans of 7 feet between joists and flexes (deflects) under foot traffic. This typically is not a good condition onto which a ridged roof system, such as a bituminous one, should be installed. It cannot be expected to accommodate such deflection. PHOTOS: Hutchinson Design Group Ltd. [Read more…]

Several ‘Sandwich’ Roof Assemblies Mitigate Sound Transfer

We all want a roof over our heads to protect us from the cold winter months, hot summer months and precipitation year round. How much thought goes into the sound-control construction of a roof, though? Have you considered the acoustic properties of your roofing system? Admittedly, acoustics is not a topic that many roofing contractors think about. The construction of a roof, however, can have a significant impact on the sound quality of the building interior. While this may not seem important in every project, it can be a critical element of the design for concert halls, theaters, auditoria and even school classrooms.

Sound Isolation

The acoustics of a space depend on many criteria, including sound isolation, sound reflection, impact noise and sound transfer. In many cases, particularly in noisy, urban environments, there is a need to prevent loud outside noises, such as traffic, sirens and airplane noise, from entering quiet spaces. Sound isolation depends on the entire envelope of a space, including external walls, windows and roofs.

Green roofs, particularly the “intensive” version, which includes several inches of heavier-weight soil, can provide effective sound control.

Green roofs, particularly the “intensive” version, which includes several inches of heavier-weight soil, can provide effective
sound control.

Historically, roofs over sound-sensitive spaces have been built with fairly dense materials, such as concrete, which by themselves are relatively effective in blocking sound transfer. As construction methods have developed, however, more lightweight construction is being used. If thought and care are not given to the assembly, these lightweight construction methods can cause serious issues with acoustics. Rain noise, mechanical noise and other exterior sounds can all transfer readily through a thin, lightweight roofing system.

In an effort to use lighter-weight construction, a “sandwich” assembly may be used to mitigate sound transfer. Similar to an Oreo cookie, a sandwich assembly’s outer layers are comprised of a heavy, dense material, and the inner filling consists of insulation and/or airspace. The materials of this assembly can differ from concrete to roofing board, rigid insulation to fibrous insulation, gypsum board to acoustic ceiling tiles. The components can be combined in a variety of ways, each with varying levels of sound isolation.

One of the principle phrases often heard when discussing sound isolation is “mass air mass”, which refers to the separation of two bodies of mass by an air space. The greater the mass and the deeper the air space, the more sound isolation will result. For this reason, a heavy mass, such as 5-inch concrete, followed by a deep air space, such as an 18- to 24-inch ceiling cavity in which ducts are run, followed by a continuous layer of drywall ceiling will provide a high level of sound isolation. Additional steps, like adding sound-absorptive material to the air space and/or using resilient connections when supporting drywall, further improves the sound isolation of the assembly.

Sandwich Roof Assemblies

Several sandwich roof assembly approaches are possible, including:

Good: Multiple layers of dense roofing board (at 2.5 psf per board, a final density of 10 psf or four-ply is often recommended) on either side of insulation, which ideally would be a sound-absorptive fibrous fill, like mineral wool, can reduce sound transmission. This approach is similar to a “floating floor”, often used in interior spaces to isolate sound transfer from one room to another. (Equivalent Sound Transmission Class, or STC, ratings can range from low 50s to low 60s, depending on whether a ceiling is included below the deck.)

Drywall ceilings hung on resilient hangers in conjunction with a lightweight roofing system provide even greater sound isolation by virtue of the resilient connection or “decoupling” of the drywall layer from the rest of the building structure.

Drywall ceilings hung on resilient hangers in conjunction with a lightweight roofing system provide even greater sound isolation by virtue of the resilient connection or “decoupling” of the drywall layer from the rest of the building structure.

Good: Green roofs, particularly the “intensive” version, which includes several inches of heavier-weight soil, can provide effective sound control. These can be part of a sandwich approach with airspace or rigid insulation between soil and a more-dense roofing material, similar to the roofing board described in the previous example. The mass-air-mass combination is similar to the approach just mentioned, and the benefits of green roofs appeal to many building owners for a multitude of reasons, including minimizing urban heat islands and storm-water management.

Good: A 5-inch slab of normal-weight concrete (150 pcf) has a density of 62 psf. This tried-and-true method is still used regularly and often proves to be the most cost-effective method of enclosing a space. The best sound isolation will occur if this is used in conjunction with a ceiling below, but on its own it still provides a reasonable level of isolation in many environments. This isn’t technically a sandwich system unless paired with a ceiling below or a green roof above. (Equivalent STC ratings can range from low 50s to low 80s. The highest ratings require pairing a resiliently hung ceiling with the concrete, as described under “Multi-function Roof Assemblies”.) IMAGES: Threshold Acoustics LLC [Read more…]

Improve Your Relationship with Condo Associations

Is your roofing company struggling to make ends meet, or are you searching for new ways to make your company thrive? I think at some time in every business owner’s career they come to a point where they realize that just being “good” isn’t good enough in today’s competitive marketplace unless your service or product is truly niche.

In the roofing industry, let’s be honest, there are quite a few of us out there. In my neck of the woods it’s not difficult to find two-dozen or more competitors. This is why my firm has to come up with ways to set ourselves apart from the pack. One of the best ways to do this is by improving our business relationship with condominium associations and board members, as well as property managers. These relationships have led to us not only being the first contractor called when there’s a problem at a building, but we also have received a number of referrals.

There are many ways to build relationships with condo associations and management companies, and I can almost guarantee that if you do it right your company will see gains like never before.

Network

To get your foot in the door, search the Internet for “condo management associations”. In my area of southwest Florida, the Falls Church, Va.-based Community Associations Institute is active. We joined the group and attend its chapters’ networking events. Groups like these are where condo managers decide on their “favorite” contractors. They talk to each other; “word of mouth” is a huge marketing tool. If you want to be on their minds, you need to be on their invitation list for these meetings. Once these relationships are built, managers won’t be looking for cheap bids anymore. You put yourself closer to the driver’s seat for potential negotiations.

If you personally don’t have a profile on LinkedIn, you’re missing a HUGE opportunity to network on America’s largest social-networking platform for professionals. Join LinkedIn for free and, if you own a company, be sure to build your company page, too. Then search for groups in your state or city that relate to property managers or condo associations. Most importantly, don’t just be a fly on the wall in these groups. Comment on other members’ posts and share your knowledge. This is how you add value and what makes your company unique. Being active online will increase activity toward your website; by the way, you should have a website worth sharing.

Don’t Sell; Educate

When joining these groups, don’t just sell yourself or your company because people are tired of being sold. Instead of touting how great your company is to every property manager you meet, try finding out their pain-points and objections and then educate them about how your services will make life easier for them. This is HUGE!

We recently asked approximately 50 building managers via email what frustrated them the most in dealing with contractors. We received informative answers that will help our business. Consider the following frustrations building managers cited:

  • Long response times: 25 percent
  • Taking too long to perform tasks: 25 percent
  • Not returning phone calls: 25 percent
  • Not following HOA rules/regulations: 15 percent
  • Dirty contractors and vehicles: 10 percent

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Four Tips for Great Leadership

In the past three and a half years, Saratoga Roofing & Construction of Oklahoma City has grown from $6.5 million in annual revenue and four employees to a company earning $50 million with 265 employees. To what do we attribute this phenomenal growth? Great leadership.

It has been said: “A good leader inspires people to have confidence in the leader. A great leader inspires people to have confidence in themselves.” Being a great leader takes commitment, confidence and clarity. The old-school method of employing scare tactics—“If you don’t do what I tell you to do, then there’s the door!”—doesn’t cut it anymore in today’s business world. Besides, if you still subscribe to the “It’s my way or the highway” way of thinking, you’re going to alienate everyone who works in your company or organization and nothing will be accomplished. During my career, I have experienced owners and/or leaders who used authoritarian leadership and, in my opinion, they will not make it during the next decade.

Denver Green, Saratoga Roofing & Construction’s president, shares four reasons why Saratoga will continue to be a successful company during the next decade:

1) We continuously work to set a clear direction for our teams. Clarity will always lead to desired results. If you aren’t clear about where you’re going, do you think your team will be? As a leader, my role is to be the visionary who paints the picture for them to follow. If our leaders aren’t clear about the necessary steps our staff needs to accomplish goal, then a lot of time is going to be wasted running around in circles. Our consultant, Masterthink, ensures every company executive has a clear goal with action plans tied to dates and people who are accountable for executing the goal. If needed, we draw a roadmap on paper outlining the full process, starting with the objective and detailing what each person is responsible to complete. The better your directions are, the easier it will be to meet the goal.

2) I work hard to make sure my actions match my intentions and visions. As the leader, I always need to know what I envision being the final outcome of the project/task we’re asking our employees to execute. Do you want to “wow” a client with an exceptional product presentation? Can you see the final project completed? What does it look like to you? Are you excited about this task? The level of my commitment and enthusiasm needs to come across loud and clear to our team. If I’m “ho hum” about the outcome, then guess what? That’s the attitude that will be adopted by members of my team. Some of us are “big picture” thinkers. We forget about all the details that lead to the big picture, but as the leader of Saratoga, I can’t allow myself to let those last-minute details slide. If I do, then the final outcome will definitely not be to our liking.

3) Creating a cohesive team has been a real key to our success but also a big challenge. I must have confidence in my team and their abilities. Knowing who fits in where on our team is crucial to creating success. We know it is critical to assign the “right” people to the “right” tasks. If one of our employees doesn’t like dispatching but loves to work on data entry, then we assign him or her that job. Knowing the strengths of each member of our team is crucial in achieving a successful end result. Forcing someone to take on duties he or she absolutely hates creates resentment, and resentment slows down the entire project or leads to poor performance. Our company utilizes the online assessment tool StrengthsFinder as a means to understand
the strengths of our employees so we can maximize their abilities and strengths to the fullest extent.

4) Work smarter, not harder. I know we have heard this phrase a million times, but it bears repeating. Learning to delegate the workload to the right person will lift some of the weight of turning in a top-notch end result off your own shoulders. My role is to be the visionary—not the micro-manager. I model what it means to be a leader and a follower and, in turn, I take great pride in inspiring and creating great leaders for the future.

As a member of the Saratoga Roofing & Construction team, I can truly say this is the “Saratoga Difference”.

Cold-weather Considerations

During the next several months, it will not be unusual to see roofing crews working hard to complete projects or trying to get an early start on spring projects. Executing roofing projects during the cold months of winter creates a unique set of safety hazards and challenges for designers, contractors and building owners. Not understanding or failing to address cold-weather considerations will impact installation quality and long-term roof performance.

In many cases, designers don’t plan on specifying a roof system specifically for installation during the cold winter weather. However, anticipated funding approval and construction schedules can change, quite often forcing a designer to make changes to accommodate the cold weather. Designers should consider changes related to roof installation methods, as well as adhesive type, to ensure the roof can be installed as designed in colder, potentially snowy, wet weather.

Materials

This adhesive is not stored properly.

This bonding adhesive is not stored properly.

When choosing materials to install, it is important to remember most roofing materials are not designed to be installed in cold-weather situations, especially when ambient temperatures dip below 40 F. Membranes, adhesives, equipment and contractors will perform differently in colder temperatures, so planning ahead and considering how the cold weather will impact material selection, installation time and quality is critical.

Membrane: Storing roof membrane at the job site during warm months is straightforward: Keep the rolls off the ground and protect them from moisture using breathable tarpaulins. As the weather grows colder, the dew point and temperature typically come closer together, increasing the potential for condensation and frost forming on materials. Keep material goods warm and dry by storing them inside a conditioned space or in a heated job trailer. Keeping materials warm and dry will reduce the risk of moisture being introduced into the roof system during construction and minimize the possibility of blisters and other deficiencies in the completed roof system. In addition, material rolls will become more rigid as they get colder, requiring additional time to kick out and relax before installing.

Adhesives and asphalt: When dealing with membrane adhesives, there are generally two main categories to consider solvent-based and waterborne adhesives. Recently, the use of waterborne adhesives has been growing steadily as a result of low odor and VOC code requirements. Both types of adhesives have similar manufacturer recommendations for storage temperature, typically between 60 and 80 F.

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Nashville, Tenn., Begins Revitalization of Its City Center with a New Convention Space that Features a Truly Unique Roof

It isn’t often that a nightmare becomes a pleasant reality. Andy Baker, vice president of Raleigh, N.C.- based Baker Roofing, recalls the year he spent as project manager for the roofing of the new Music City Center in Nashville, Tenn., as one of his most challenging jobs. “The logistics, a tight spot downtown, the size of the project and everything that goes along with that—thousands of people trying to work and everyone needs their material in that area at the same time. Even the unique shape of the building made it hard,” Baker remembers. “We’re glad it’s done and we can look back on it now and say: ‘Wow! We did that.’”

The Music City Center was built to be the catalyst for more development in the SoBro neighborhood of Nashville, Tenn. It is intended to create a diverse economy that won’t be affected if flooding occurs, like in May 2010.

The Music City Center was built to be the catalyst for more development in the SoBro neighborhood of Nashville, Tenn. It is intended to create a diverse economy that won’t be affected if flooding occurs, like in May 2010.

Baker and his crew of up to 50 roofing workers have much to be proud of. The completed project is the largest capital construction project in Nashville’s history and was designed to bring prosperity to the area known as SoBro, or South of Broadway, which was affected by massive flooding in May 2010. The Music City Center lies outside the flood-prone areas and hopefully will be the catalyst for more development, which will create a diverse economy that won’t be affected if another flood occurs.

In addition to the Music City Center’s imaginative design that resembles various musical instruments, the building boasts a number of features that are ideal for a high-profile project. Many of these features are located in the most opportune of places—the roof. An Energy Star-qualified thermoplastic PVC membrane covers the 643,752-squarefoot roof while a 186,700-square-foot vegetated roof literally mimics the rolling hills of Tennessee’s Highland Rim. The rooftop also hosts a 211-kilowatt solar-power system on the 1-acre area that is over the Grand Ballroom, a rooftop space that resembles an acoustic guitar in shape. Lastly, the roof collects rainwater that is funneled to a 360,000-gallon tank before it is used to irrigate the site and flush hundreds of toilets inside.

Construction Challenges

Baker and his colleagues knew the Music City Center would present many challenges even before work began. “We knew it was going to be a logistical nightmare going in but then you have to live it,” he recalls. “You would think four city blocks would be a large enough area to work from but there were thousands of contractors working and receiving materials at the same time. Trying to keep truck drivers and suppliers happy was difficult. The community was great though; there were a lot of police officers around to direct traffic.”

Baker Roofing's team of up to 50 roofing workers spent one year working on the Music City Center.

Baker Roofing’s team of up to 50 roofing workers spent one year working on the Music City Center.

Installation also proved perplexing because of the roof’s undulating slopes of 1/4:12 to 12:12. Baker likens the rolls to waves and points out in some places they were almost conical in shape. In the areas in which there was no vegetated roof, the crew fastened two layers of 1.7-inch polyisocyanurate insulation followed by 1/4-inch roof board. Then a 60-mil thermoplastic PVC membrane in a light gray color was fully adhered to the assembly. The membrane features a lacquer coating to reduce dirt pickup.

Photos: Keri Baker

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Rooftop Alterations, Like Skylights and Roof Monitors, Can Drive Building Value and Performance

Rooftops are an immensely underutilized resource for optimizing building performance. Rooftop strategies can include painting the roof white or installing a solar reflective “cool roof” to reduce summer cooling loads; covering the roof with vegetation to improve insulation, reduce storm-water runoff and provide community spaces; and mounting solar photovoltaic or solar hot-water panels to reduce utility bills.

The multiple functions of rooftop monitors. RENDERING: FCGA Architects

The multiple functions of rooftop monitors. RENDERING: FCGA Architects

Adding daylighting and ventilation through skylights and roof monitors is a strategy with growing popularity and potential. Common sense might lead us to believe that penetrating the roof with skylights and monitors could compromise a building’s insulation and thermal performance. However, with the availability of advanced products, such as glazing, suspended film and high-performance sealants, well-designed and constructed rooftop penetrations can successfully lower energy costs and improve occupant comfort and health.

Rooftop prescriptions vary for every individual project, and a variety of factors must be considered before proceeding with construction. For example, rooftop penetrations will primarily only affect the floor directly beneath the rooftop, so single-story buildings or multistory buildings with a central atrium are ideal. When further determining which types of projects would benefit from roof penetrations, the design team must perform thorough climatic analysis, examine the existing infrastructure and occupancy conditions, and weigh all variables through cost balancing. Before diving deep into analysis, it’s important to understand different types of rooftop penetrations in this capacity and how their design and operational synergies can enhance the value and performance of a building.

Design Synergies

Traditional skylights, tubular skylights and roof monitors are the main types of rooftop daylighting/ventilation penetrations and should be considered individually because of their varying benefits. Traditional skylights offer natural daylight, which can improve the health and productivity of building occupants. Tubular skylights capture sunlight from a small, clear dome on the roof; pass the light through a highly reflective tube; and diffuse the light through a lens into the building. Because of their high efficacy and smaller penetration area, tubular skylights have better thermal performance and are more suitable for harsher climates than traditional skylights.

Roof monitors are vertical fenestrations built into raised structures atop the roof. If the monitors are operational, they contribute exponential building-performance enhancements beyond the other penetration types, including stack-effect ventilation. The figure above depicts the many functions of roof monitors: natural daylighting, ventilation, passive heating and cooling, glare reduction and structural support for rooftop solar-power systems.

As with skylights, roof monitors help disperse natural daylight more evenly and completely throughout a room than windows on the side of a building. When paired with thermal mass, such as concrete or water, vertical glazing on the roof helps capture heat from the sun to offset the building’s heating load.

Glare presents a big problem for worker productivity in buildings; careful design of roof monitors and ceiling systems can help distribute the light and reduce contrast glare. Finally, monitors can be topped with angled roofing that matches the optimal sun exposure angle for solar panels mounted atop.

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Attention Roof System Designers: Numerous Roof Components Work Together to Affect a Building

There has been a great deal of opinion expressed in the past 15 years related to the roof cover(s), or the top surface of a roof system, such as “it can save you energy” and “it will reduce urban heat islands”. These opinions consequently have resulted in standards and code revisions that have had an extraordinary effect on the roofing industry.

The building type should influence the type of roof system designed. Some spaces, like this steel plant, are unconditioned, so insulation in the roof system is not desired.

The building type should influence the type of roof system designed. Some spaces, like this steel plant, are unconditioned, so insulation in the roof system is not desired.

Let’s say it loud and clear, “A single component, does not a roof make!”. Roofs are systems, composed of numerous components that work and interact together to affect the building in question. Regardless of your concern or goal—energy performance, urban heat-island minimization, long-term service life (in my opinion, the essence of sustainability) or protection from the elements—the performance is the result of an assembled set of roof system components.

Roof System Components

Energy conservation is an often-discussed potential of roofs, but many seem to think it is the result of only the roof-cover color. I think not. Energy performance is the result of many factors, including but not limited to:

Building use: Is the building an office, school, hospital, warehouse, fabrication facility, etc.? Each type of building use places different requirements on the roof system.

Spatial use and function be low the roof deck: It is not uncommon in urban areas to have mechanical rooms or interstitial spaces below the roof—spaces that require little to no heating or cooling. These spaces are typically unconditioned and unoccupied and receive no material benefit from the roof system in regard to energy savings.

Roof-deck type: The type of roof deck—whether steel; cast-in-place, precast and post-tensioned concrete; gypsum; cementitious wood fiber; or (don’t kill the messenger) plywood, which is a West Coast anomaly—affects air and moisture transport toward the exterior, as well as the type of roof system.

Roof-to-wall transition(s): The transition of the roofing to walls often results in unresolved design issues, as well as cavities that allow moisture and vapor transport.

Meanwhile others, like this indoor pool, require extreme care in design and should include a vapor retarder and insulation.

Meanwhile others, like this indoor pool, require extreme care in design and
should include a vapor retarder and insulation.

Roof air and/or vapor barrier: Its integration into the wall air barrier is very important. Failure to tie the two together creates a breach in the barrier.

Substrate board: Steel roof decks often require a substrate board to support the air and vapor barrier membranes. The substrate board also can be the first layer of the roof system to provide wind-uplift resistance.

Insulation type: Each insulation type—whether polyisocyanurate, expanded polystyrene, extruded polystyrene, wood fiber, foam glass or mineral wool—has differing R-values, some of which drop with time. Many insulation types have differing facer options and densities.

The number of insulation layers: This is very important! A single layer of insulation results in a high level of energy loss; 7 percent is the industry standard. When installing multiple layers of insulation, the joints should be offset from layer to layer to avoid vapor movement and thermal shorts.

Sealing: Voids between rooftop penetrations, adjacent board and the roof-edge perimeters can create large avenues for heat loss.

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A Solar Installer Explains the Many Ways Roofing Contractors Can Be Involved in Solar Installations

The solar-power industry has changed dramatically in the past five years. Products and manufacturers have come and gone; tax incentives have become less attractive; and requirements for utilities to maintain a certain percentage of their energy portfolio from renewable sources are not enough to help the market in most places. Despite these negatives, unique financing mechanisms and the remarkable decrease in the cost of solar panels keep the industry booming. These ups and downs demonstrate why Matthew Bennett, vice president for design and engineering and founder of Dovetail Solar & Wind, Athens, Ohio, refers to the industry as the “solar coaster”.

Bennett’s business, which was established in 1995, installs solar on residential and commercial buildings. As such, he has worked with a number of roofing contractors over the years and sees synergies between the trades. Roofing asked Bennett how roofing contractors and solar installers can improve their relationship and achieve successful solar installations upon watertight roofs.

Roofing: When must you coordinate with roofing contractors?

Bennett: On almost every commercial roof where roof penetrations are required we’ll have a roofer come in and flash the penetrations and sometimes install a sleeve to get our conduit off the roof and into the building.commercial solar array

The other common reason for coordinating with a roofer is because the roof may be under warranty. Sometimes the warranty is held by the roof manufacturer, so we receive a list of roofers who can do the inspection. Usually there’s an inspection that needs to happen before and after the solar installation. We’re sometimes paying $1,000 to get inspections.

A lot of times we’re not fastening solar panels to flat commercial roofs; we’re installing what’s called a ballasted system where we may need to use an approved pad or put down an additional membrane to protect the roof from the pan that is holding ballast and keeping the array on the roof. Sometimes different roofing manufacturers are picky about what they allow on the roof and different kinds of roofs require different treatment, so it’s important to have a good roofing contractor available.

Roofing: When you hire contractors, what are you looking for?

Bennett: We’re looking for a roofing contractor that does quality work at a fair price because, I’ll be honest, we’ve been overcharged by roofers more than any other subcontractor. We take notes when we work with a roofing contractor: how easy they are to work with, how responsive they are to emails and phone calls, the quality of work and the price. We know roughly what to expect after being in business all these years. If we get a fair quote from a recommended contractor, we’ll often go with them without looking at other bids. We prefer to use a roofer who is familiar with the roof. A good relationship with the customer also is an important consideration.

Roofing: Are there situations in which you defer entirely to the roofing contractor?

Bennett: It’s a little unusual. We just put a system on a slate roof on a million-dollar home. The roof was very steep and we didn’t even want to get on the slate, so we hired the roofer to install the rails and solar panels. We did all the electrical work and procurement. We provided one of our crew leaders to be there the entire time to train the roofing crew and help them because they had no experience with solar. They knew how to get around on a slate roof and mount the solar flashing and they actually installed the whole array. They did it in not much more time than we would’ve done it. We were very impressed with them.

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