Between you and the sky

Jan. 25, 2007
Paying attention to the complex overhead structure might prove to be a huge difference to your bottom line.

At the most basic level, the typical plant manager or plant engineer is responsible for the integrity of the building envelope and its contents. Security demands that doors and windows be capable of keeping the undesirable elements outside. Safety demands that the floors be smooth enough for forklift traffic but not so slick that someone can slip in a wet spot. HVAC efficiency demands that exterior walls be sealed against infiltration. All this is covered by the great umbrella we call the roof. Paying some attention to that complex overhead structure might permit the plant professional to make a difference in the plant’s bottom line.

So, keep those ideas in mind and come with me for another dip into the digital morass we call the Web in search of practical, zero-cost, noncommercial, registration-free resources you might find useful for keeping the rain off your equipment as well as making a positive contribution to society. Remember, we search the Web so you don't have to.

Reading the roof

First, you’ve got to start with a sound platform. Many of you are familiar with the idea of using thermography to inspect roofs. The images the camera generates can reveal the sometimes subtle temperature differences that indicate incipient roof problems. These inspections can help you decide whether the problem you uncover deserves immediate attention or if it’s something that can be postponed a bit longer. The Infraspection Institute, Burlington, N.J., is a noted source of information about thermographic analysis as it applies to the full spectrum of industrial applications. To that end, the organization’s Web site offers its “Tip of the Week,” and if you dig into the organization’s archives, you’ll find no less than 15 roofing-related items that might be useful. The way to access these tips is to go to and hover your cursor over “Technical” in the upper left to access the drop-down menu, while you select “Tip of the Week” and then “Sortable List.” Click on the word “Category” and the entries will sort alphabetically. Scroll down to “Roof.” Voila!

Due diligence

As published in the pages of Inside Self-Storage Magazine, Greg Thirnbeck’s article “Got It Covered” is aimed directly at the person responsible for metal-roof maintenance, repair and restoration. The part of the article covering preventive maintenance offers a list of the elements that you ought to inspect and it tells you what to look for during your foray to the roof. On the other hand, if it’s time to replace the roof, answer Thirnbeck’s dozen questions, which are designed to help you decide which type of roofing would be best. Also, you’ll find an overview of the available options if you merely need to reroof the building. Finally, check out the eight questions you should answer before selecting a roofing contractor. You’ll find this material built up at Enjoy the read.

Design tips

Despite the multi-year warranty that came with your current roofing product, there’ll come a time when you’re going to be looking for a roofing contractor, perhaps in desperation. Unless your corporate plan is to roll over and play dead during the project negotiations, you should take an active role in specifying what’s to be installed up there. That requires knowing something about best practices. After all, you want your roofing project RFP to describe the most cost-effective roofing system for the prevailing situation.

Johns Manville offers some product-neutral material you might find useful at Simply click “Roofing” (at the top center) then click “Literature and Bulletins.” A final click on “Trade Magazine Articles” will access links to a collection of 10 roofing-related tutorials. Topics include roofing system selection, closed-cell foam insulation, roof inspections, use of edge metal, recovering a roof, roofing trends and more. This should give you a start on specifying exactly what your plant needs to have installed.

Hot wired hardware

The National Electrical Code addresses the relationship between wire size, ambient temperature and current. The difficulty is that your local meteorological services measure temperature in the shade. When a hot sun is baking the roof, it’s likely that the relevant ambient temperature — the one found inside the conduits running across the roof — will be far higher than you ever imagined. This might lead to the very unsafe condition the NEC was intended to prevent. So, if you’re concerned about any of the electrical equipment on your roof, you might want to read “Effect of Rooftop Exposure on Ambient Temperatures Inside Conduits,” an article by Lindsey, Black and Sharpe that appeared in the January/February 2006 issue of IAEI News, published by the International Association of Electrical Inspectors. This document presents the results of meticulous research into the temperature corrections, all as a function of roofing type, color and height of the conduit above the roof surface, that need to be added to the standard temperature calculations and estimates. This is something you ought to have in your back pocket. It’ll come in handy one day and you can get the goods at

Active roofs

Unless you take some affirmative action pretty soon, that ol’ summer sun will be beating down on your roof, and that will do more than increase your air conditioning load. You could, of course, install light-colored roofing material and add layers of insulation beneath the roof deck, but it might be better to turn the roof into something more than a passive building element.

Why not put that otherwise wasted sunlight to work by heating water, as is sometimes done in the residential sector? Before you respond, check out some basic ideas from the U.S. Department of Energy. Dip your mouse into the hot water found at The site houses two clusters of what appear to be unduplicated content. Accessing the first batch requires a click on “Solar Energy Technologies” at the left side of the screen, which opens a link-rich page. Access the second cluster through a click on “Consumers” found under the Quick Links heading on the right side of the screen. When the page loads, click on “Solar Water Heating” that appears under the new set of quick links. Whatever your response, it should compare the cost of heating water with fossil fuel with the payback solar heating provides.

On the other hand, how about rearranging the roof elements for ecological purposes? Aramis Velazquez from, LLC, in Alpharetta, Ga., runs a site that bills itself as “the greenroof industry resource portal.” You make the decision about that claim after you examine the offerings. As an aside, this site explains why these projects should be called “greenroofs” instead of “green roofs.” You’ll find Velazquez’s site to be one of the more technically oriented resources. For example, it offers a searchable Greenroof Projects Database, a tabulation of more than 450 greenroof projects around the world, showing project name, location, roof size, planting type, whether the project is open to the public and more. Public access should prove valuable to the plant professional wanting to tour a few greenroofs before taking the next logical, bold step. Because the deadload on the roof is important, the site also has a link to Green Roof Stormwater Tool, a free download that quantifies the split between rainfall runoff and absorption. Finally, this is where you can access Greenroofs 101, a lengthy tutorial covering nearly every initial decision you’ll need to make for your own greenroof project. Your desk rodent should climb way up to the top of the stairs to get into for the details.

The research team at the University of Wisconsin runs the Great Lakes Wisconsin Aquatic Technology and Environmental Research (WATER) Institute in Milwaukee. In 2003, as part of their Green Roof Project, the Institute installed a garden covering nearly 8,000 sq. ft. of their building’s roof. The goals were to minimize storm water runoff and associated pollution, quantify the economic and ecological benefits of greenroofs, develop expertise in their design and installation, and provide an opportunity to educate surrounding businesses. You can get the full story by going to and entering “green roof home” in the search function at the upper right corner. From there, finding the appropriate page is pretty intuitive. You’ll learn the four direct benefits that rooftop plantings offer, the differences between intensive and extensive greenroofs, and the differences between modular and built-in-place roof gardens. There’s also a page of links to other relevant Web sites. Unfortunately, the link to “Detailed Specifications” wasn’t functional when this engineer explored the site. Nevertheless, here’s an educational opportunity that’s worth your time.

It’s a record

In the abstract, you’d naturally expect the folks at Georgia Tech to know a little something about rooftops. That they actually possess such knowledge is nothing remarkable in itself, until you understand that the knowledge we’re talking about resides in the School of Electrical and Computer Engineering. The connection between rain cover and electrons is found in one of the school’s laboratories, located on a campus building rooftop. On that lofty site, they’ve installed a large-scale, standalone photovoltaic system that’s connected to the grid. The 342-kilowatt system is reported to be the largest such installation in the world. While it covers less than an acre, its output is sufficient to power 28 average homes. Imagine for a moment what you could do with some of the area on your own otherwise unused plant roof. If you think it’s a spark of an idea worth exploring, send your mouse over to and have it click on “Research Horizons magazine,” found in the upper left corner. When the page loads, scroll down and click on “Summer/Fall 1997.” Click on the image and read what happens when there’s no rainy night in Georgia.

Bright ideas from the government

While we’re on the subject of solar power, you shouldn’t be surprised to learn that our tax money is funding the National Center for Photovoltaics, a facility operated by the U.S. Department of Energy's National Renewable Energy Laboratory and headquartered in Golden, Colo. The Center’s home page ( has a pair of good features. The first is a set of estimation tools that roughly evaluate the practicality of connecting your rooftop sunlight to the grid. Be patient — it might take you a few minutes to figure out how to use this map-based application. Once you input your chosen location, the basic output you’ll get back is a month-by-month tabulation of the energy that can be generated and its value. Of course, you can input the relevant variables manually if you don’t want to use the default values the software assigns. When you’re done testing this feature, check out the second goodie — the FAQs. It will give you a clue whether this is a viable project.

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