Uncovering the Answers

Jan. 28, 2003
Roofing Questions Addressed By One of the Industry’s Experts
When Richard (Dick) Fricklas talks roofing, everyone listens. Based in Centennial, CO, this bona fide roofing guru has spent more than 40 years immersed in the industry as a chemist, lecturer, consultant, and author. In 1999, Fricklas was given the J.A. Piper Award by the National Roofing Contractors Association (NRCA) and a Lifetime Achievement Award from the Educational Foundation of the Institute of Roofing and Waterproofing Consultants, in addition to the MRCA’s McCawley Award and ASTM’s Voss Award he received previously. Recently, the editorial staff at Buildings had the fortunate opportunity to discuss roofing basics with him. What follows are excerpts from that conversation.Dick, how does a building owner know it’s time to re-roof?It really depends on the owner’s threshold of pain. Some buildings are just simply much more important than others and as soon as the roof starts giving the owner fits, it’s gone. On the other hand, a more involved owner has had leaks in the past and he’s got some maintenance people who can do more than just put a bucket out. In that case, when they do get some water in, they’ll send somebody up on the roof and make some emergency repairs. As soon as the weather allows, they’ll go back and try to fix it. Their ability to live with a little water is much greater and because of that, there’s not one snappy answer to when it’s time to re-roof. It’s more to do with the owner’s tolerance than a technical issue.In terms of trying to crunch some numbers on it, when [the roof] gets up in age and it’s been properly depreciated, you should replace it whether it needs it or not. That comment sounds silly, but for many materials [there] is a wear-out factor at which point the economics are such that you are spending too much money patching it, and you would have been better financially (because the re-roof is capitalized, rather than an operations and maintenance account) to just spring for the capital, tear it all off, and start fresh. On a percentage basis, my guess would be, if you get much above five percent of the replacement cost of the roof in repairs every year, you’re spending too much money and you’d probably be better off to get rid of it.What about recovering? How can an owner company determine whether it should recover or do a total tear-off and re-roof?Certainly the major determinant is going to be the condition of the substrate. For example, the building codes now specifically say you can’t roof over wet material. They’re not quite as clear about deteriorated material, because something could have gotten wet and pulverized and turned to mush but it’s dry now. That would still make a terrible substrate. To make that determination, I think the average owner needs to hire a roof consultant. The consultant will want to cut into the roof at various places that are reportedly the worst or have known leakage, and other areas which have had no problems so that he can compare the condition of good and bad [samples].The consultant [can conduct] a number of non-destructive tests available as well. These are based on three physical principles – one of them is infrared (IR). This is a survey that is typically done at night. Infrared measures heat loss or heat radiating from the roof. The second physical principal is one [that involves the] detection of the presence of excess hydrogen atoms. Everything has hydrogen in it – but if when they’re doing the survey, they find one area where the numbers are higher than everywhere else, you can guess that that area has H2O. [Then the consultant will] do a contour map of the roof, plotting the level of hydrogen off what is called nuclear backscatter. That’s the second method for surveying a roof, non-destructively. Either you look for temperature anomalies, which is infrared, or hydrogen anomalies, which is nuclear. And then the third physical principle is called electrical capacitance. In the capacitance method, you’re measuring the electrical resistivity of a field. What you’re looking for is some places [where] the conductivity is greater than other places, and usually that’s due to the presence of water.[The consultant will return] after they’ve made a contour map of the IR or capacitance data and core areas that have the highest numbers and the areas that have lower numbers. These will be taken back to the lab and physically measured to determine how much water is in them. That validates the moisture survey. All false anomalies have to be eliminated and you do that by actually punching holes in the roof and verifying that the contour map is correct.Once you have that information, you can examine the plan of the roof and if only five percent of the total area is wet and it’s all confined to one section of the roof, you would do a partial replacement. [Simply remove] that five or 10 percent of the wet insulation, go right down to the deck and replace it with dry [insulation], and then recover the entire roof.On the other hand, if you have the same amount of wet material but it is six square feet here, and thirty square feet there, and it looks like the roof’s got freckles (of wet areas), one would probably decide to tear everything off. By the time the roofer ties in all those replaced areas with the areas that he’s not replacing, fits the insulation – from a labor point of view, it would be much more efficient just to tear it all out.What can happen if you recover over wet material?The presence of water in that old roof has been found to be acidic and will eat the screws. So all of a sudden the new roof looks beautiful but it’s no longer attached. When a hurricane or severe wind comes along and the roof blows off, nobody knows why. That’s one reason why you don’t want to roof over wet material – the corrosion factor. It becomes very important to an owner to know what the moisture situation is before he contemplates a recover. It is a higher risk, in terms of durability.Another reason why one would NOT recover would be that many of the manufacturers will not warrant a recover. They’ll only give you a warranty if you go down to the deck or they will give you a very limited warranty (10-year warranty). But if you tear everything off, they might give you a 20- or 25-year, no dollar limit (NDL), top of line, best warranty they have. They’re certainly not going to give you a blue ribbon warranty in a high-risk situation.How can you be sure about getting a quality installation?My opinion is to hire the best roof consultant and have that roof consultant provide full-time inspection. The other benefit one gets out of [hiring a consultant] is if it’s known at the time of bidding that “This consultant of good reputation is going to be on the job,” it may scare away some of the people who were going to bid low, planning to cheat.I would want to work with approved contractors, and I would want an outside independent consultant to actually be there … from when the deck is installed on up.Light-colored roofs – is this THE best environmentally friendly choice for every facility?It’s unfortunate that asphalt is not white and dirt isn’t white. There are two issues – one of them is simply heat load on the building. And in that case, the more you go into the south (everywhere from Florida along the Gulf Coast, all the way to San Diego), one would think that white roofs would be ideal because they reduce air-conditioning load, because the roof simply doesn’t get as hot. Mainly what you’re looking for is high reflectivity.There is certainly an emotional issue or aesthetic issue, that’s going to [cause some to] say, “White may be good on your air-conditioning load, but it is not something that I prefer or accept aesthetically.” The second issue will be that nothing shows dirt as well as white. So even if I choose the whitest of the white, it isn’t going to stay white. And everything will darken it – from wind-blown dirt and dust to algae and mold to flaking off of the coating (showing the dark substrate underneath), to the foul things that wind up on a roof (the greases and oils that are coming out of stacks).The other issue is good drainage – if the roof ponds water, or the drainage is poor, it will darken much quicker. So if you really want white for reflectivity on a big, flat commercial roof, [pay] more attention to drainage. And, probably, there will have to be a program for washing the roof.There are secondary issues – one of them is the choice of a white roof in a cold climate. The problem is, if you live in Chicago and you put these smooth, white single-ply roofs on, it’s not going to melt ice and snow very well. When the sun shines on it, that reflectivity is going to be your enemy and there is a potential to have greater build-up of ice, which could lead to collapse and other problems. In addition, a wet, white plastic is about as slippery as you can get. So we may run into some safety issues, which nobody has paid much attention to.What advice do you have for building owners regarding managing their roofs?I think it’s going to be essential that they have more knowledgeable people in-house. If I managed a big facility, I would want to have one or two people on my staff whom I send to roofing symposia on an annual basis.I would want my trained facility people to start tracking every roof. I would put together a computerized performance folder, so I knew the age of each roof (so that when somebody asks in the future, they’d be able to tell me that the PVC roofs on this facility are only lasting X years, and the rubber roofs last Y years). They just don’t simply have the analytical tools to tell what is actually giving them the best performance. Roofing has gotten so diversified that the personnel need to know what’s up there and what the proper technique for repairing it is. In the old days, you ran over to the hardware store and you bought a bucket of plastic cement asphalt mastic and you smeared it on everything that looked like it might be leaking. But you can’t do that with a plastic, rubber, metal, or other system. One has to [select] materials that won’t degrade the roof, recognizing that if it’s a weldable plastic, [the roofer will] need to have appropriate patching materials as well as an electric outlet on the roof to plug in a welding tool. The owner needs to have skilled people and to find a way to budget for their salaries, to budget for the tools and equipment they’ll need (in cases of emergencies and normal maintenance), and to have computer systems to analyze and schedule the maintenance and to schedule the re-roofing.Jana J. Madsen ([email protected]) is senior editor at Buildings magazine. To hear more about roofing from Richard Fricklas, visit (www.buildings.com/newsletters) to subscribe to “Roofing News,” an e-mail newsletter he authors monthly.

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