|Reprinted From "Roofing Solutions Magazine , Reference Manual for Property Managers, Owners, Architects and Specifiers"
April 2004; Vol.I, No. 1
|Aggressive Maintenance Positively
Pays Big Dividends to Building Owners
By Chuck Marvin, RRC
What percentage of your clients have formal aggressive maintenance programs? Do you insist on evaluating the good roofs along with the clients’ specific request to replace older failed roofs? Is every applicable roof surveyed for moisture annually, visually observed, and identified work made a priority? Often it is said, “The owner will not pay for it,” or “it’s too complex.” As roof consultants we should not base our success on the number of roofs replaced but the number we prevent from failing. A discussion on maintaining roofs should be a part of every client meeting.
Most of us understand if $500,000 is spent on roof replacement while several other restorable roofs fail costing more, we are not progressing. The replacement may be a lower priority to a restorable roof. If repairs can buy a few years (or the leaks do not present a safety hazard, structural concern, or otherwise can be controlled) then spend the money to prevent failures first.
Of course, if the roof does not leak in the building and an aggressive maintenance plan is absent, the owner will not know a roof is in trouble until it is in a more advanced stage. As their consultants we should be convincing our clients to make aggressive maintenance a high priority for their benefit.
The number of articles written about the benefits of preventive maintenance programs is vast and wide. Almost as many articles have been written about management programs and the incorporation of moisture surveys to enhance effectiveness. To many the benefits are obvious. Mr. Dennis Firman, PE, who is the Chief, Maintenance Division of the Department of the Air Force, has written a dynamic article on this subject. It was published during June of 1988 in Roofer magazine and drew a conclusion that the owner’s choice not to have a maintenance program could cost 15 cents per square foot per year. Why is it, then, that so few owners have aggressive maintenance programs for their roofing assets?
More recent articles, including one by Richard Fricklas published in November, 1993 in RSI magazine, suggests 7 cents per square foot is lost per year based on an ASTM formula designated E-917. This article is interesting because Mr. Fricklas acknowledges that proof is lacking. The formula used in ASTM E-917 is offered as a way to obtain evidence to back these conclusions. Although it’s a different source confirming again the virtues of a formal maintenance program, it’s still not fact.
Thinking the missing element might be empirical proof, I solicited a few of my long established clients for help. I asked them if I could conduct an audit of existing programs with the results available for publication. Upon review of the written responses, one client stood out: a large manufacturer in North Carolina that produces compact discs and has critical production areas inside. Mr. Gerry Martin was in charge of correcting and maintaining the roofs that were about (12) twelve years old in 1988. Some leaks were occurring which needed repair; however, his focus was always on maximizing their long-term service life.
As a result, Mr. Martin set up an aggressive maintenance program. Hard choices were made in response to several recommendations from different sources. Mr. Marin’s choice to employ an aggressive program has easily saved a few hundred thousand dollars. This option is normally not selected. Rarely, however, are the results from the good or bad decisions documented well enough to show verifiable results. Mr. Martin and his company are an exception.
We need to define the basic contrast in approaches for this article. The first approach is to do nothing. This entails calling for repairs only when the roof leaks. A moderate maintenance plan would require visually inspecting the roof once a year or so and perhaps scanning it near the end to determine if a re-cover is possible. An aggressive approach would be to have a formal inspection twice a year combined with an annual moisture survey. An in-depth, computerized management program should be included for larger, more complicated facilities. The above definitions are similar to those used by Mr. Firman and Mr. Frickas.
Depending on the roof’s construction, different equipment would be used for moisture surveys to maximize effectiveness. For this client’s example, infrared was chosen as the construction lends itself well.
I was previously reluctant to recommend an aggressive approach. Perhaps a scan every third year would be practical. Based upon factual results obtained, there are few exceptions where an aggressive program with annual moisture surveys would not be my recommendation today. The following represents the original situation, reasoning for selecting the aggressive maintenance plan, and the results.
Status In Late 1988:
A few leaks existed over clean room type environments. A general survey was conducted to recommend short and long term needs. The inspection included a moisture survey with an infrared scan and membrane tensile strength evaluations.
Approximately six wet areas were defined. The largest area was roughly 120 square feet while the smallest was closer to 2’ X 4’. One existing roof leak was identified as originating from a smaller wet area located with the scan. Negative air pressure in air handling units was creating leaks blamed on the roofs. Once properly identified, this was handled separately.
The roof membrane had consistent tensile strength readings in the two-hundred- pound range meeting the recommended minimum of NBS Bulletin #55 (now NIST). This bulletin determined 200 lbs./in. as the recommended minimum concerning strength for a sound roof. Over eight random samples were taken and tested to ASTM D 2523 at 0 degrees F. Core samples appeared to have all plies well adhered and to be sound.
Problems existed: walk treads trapped water underneath, rotting the membrane, and drain valleys ponded water for several days after rains. The roof also has substantial traffic to service the formidable amount of equipment on the roof. These conditions, along with voids or other installation shortcomings, allow for an occasional leak to develop. For its size, this facility was in relatively good shape.
Rationale For Program Selection:
Based on the above findings, replacing the wet areas of insulation and roofing was specified. Additionally, repairs to the walk treads, pitch pockets, flashing and other items were included. To reduce the massive amounts of ponding water in the valleys, the installation of additional drains was recommended. That is when it became more complicated. The near clean room environment inside would mean the loss of critical production time. Also, if dust and debris reached the production equipment, a work stoppage would be required for a thorough inspection. The amount of money lost could pay for the replacement of an entire roof section.
Installing saddles, double pouring, and other methods to move the water to the drains were evaluated. The spacing between drains is as much as eighty-five (85’) linear feet. Equipment location limited the use of saddles or any tapered solution to the ponding. Insulation thicknesses, weight factors, flashing heights, and other conditions resulted in our concluding the addition of drains is the only war without increasing risk beyond its current level. Drains were the choice from a roofing standpoint. Unfortunately, the clean room conditions in the plant eliminated this as an option for now.
Not being able to include drains to ensure a sound roofing system helped in deciding to incorporate the aggressive maintenance program as a compromise. Two visual inspections combined with an infrared moisture survey annually would identify any potentially critical problems before they fully developed.
The facility is now approaching twenty (20) years of age. Excluding air handling equipment, there have never been more than a couple of minor roof leaks at any given time. The vast majority of time the facility is leak free during rain storms. How much benefit was realized from the aggressive maintenance program, if any, could now be evaluated. The answer is a great deal.
The original survey, including the infrared scan, located and defined six wet areas of insulation in 1988. Each subsequent year, up to three new wet areas were discovered until this last year when the number jumped to six. The key is to remember each of these areas is a different location and that only one or two leaked into the facility.
The enclosed drawing correlates the infrared surveys results by year. Observation of the main roof from an adjacent higher roof section reveals the repaired wet areas. The existing rock color is dark grey. The restored areas are surfaced with light colored gravel resulting in a clear contrast. This helps as the years pass to identify location, tie-ins, and any patterns that develop.
The table below summarizes the total number of wet areas found:
As mentioned, each year all wet insulation is replaced and new roofing installed. The cost of this restoration process is a valid factor in selecting a maintenance approach. Wet areas average out to be about thirty (30) square feet. The largest one identified was in 1988 in MFG. area #2 and was only one-hundred-twenty (120) square feet. This means they are repaired while small. The costs below include all inspections, restoration work, and general preventive maintenance such as the filling of over two-hundred (200) pitch pockets and coating several hundred feet of flashing (see figures on page 8).
Based on the facility being approximately 220,000 square feet and the program being provided over a seven year period, the cost is only 3 cents per square foot per year! Remember, this program was started after the roofs exceeded ten (10) years in age. The earlier years are typically much less costly and would pull this average lower still. This 3 cents per square foot number is exactly the estimated cost Mr. Firman suggested based on his experience with over 600,000,000 square feet of roofing with the U.S. Air Force. A review of five other clients conducting this type of aggressive maintenance program for at least five years also proved to be around this 3 cent number. It is conservatively accurate to say the cost of an aggressive maintenance program will fall between 3 and 4 cents per year, per square foot.
Costly Alternative – An Owners Choice Not To Employ Aggressive Maintenance.
Mr. Firman suggest the choice not to have a maintenance program can cost on owner as much as 15 cents per square foot, per year. Based on this estimate our owner would be losing $33,000 per year! If only a fraction of this amount is correct, the cost savings more than offsets the most aggressive of programs. At this point we decided to see what the PolyGram facility would look like if only patching was done to stop leaks and minimum maintenance. Very conservative estimates were used to paint a best-case scenario for the owner.
The following illustration displays the appearance of the previously charted wet areas as they would conservatively appear in 1996 with only minimal maintenance. The charted linear dimensions were expanded at a rate of about 5% per year. The fifteen-foot dimension for the largest area identified in MFG. are #2 in 1988 would have about seven years of growth. This results in a forty (40) foot dimension (it expands in both directions). To show the conservative nature of this projection, review the photographs showing two aerial infrared surveys conducted several months apart at the same location. This is another source, as the company is unrelated to the one in this example and obviously would have benefited from a maintenance plan (see page 10 and 11).
Of course this is unrealistic in evaluating the true cost to your client. If the wet insulation remains, the following are sure to happen:
A. Freeze thaw cycles will cause splits and accelerate the leaks and saturation of insulation. This takes place because the moisture is left in the insulation.
There are other negatives that play as well. We did say we wanted a best case scenario so let’s look at what happens beginning in 1996 through the year 2000. We will also give the unrealistic cost advantage of no money being spent prior to this point.
Making the above leak look even more conservative is the fact that on average three new wet areas are discovered each year. Try to chart the fifteen or so new wet areas and their growth. Replacement roofs could reduce this number: however MFG. areas 4, 5, 6, and others are expanding to the point where they are now being considered for replacement. The only question is the degree of impact, and it has been removed to provide a best case example for low maintenance. There are additional factors making the low total unrealistic. Tax consequences such as repairs being deductible in one year while new roofs are depreciated on a straight line for 39 years is just another; however, we’ll stop here.
Compare this to comparative expenditures under our aggressive maintenance program. We know, for example, there is virtually no wet insulation except the few new wet areas just beginning. We also know the facility is leak free. The roofs are getting older, however, so it’s logical to add a few thousand per year to be safe. As we are trying to convince our owners, let’s paint a worse case scenario for our aggressive maintenance program for a total cost in the year 2000.
Cost For Aggressive Maintenance Program
1988-1994: $46,500 (Factual cost)
2000: $90,000 (To paint a worst case. MFG. area #2 is replaced. Our aggressive maintenance has resulted in completely dry insulation so the roof can be re-covered. A re-cover is conducted at $3.99 per square foot).
Total Through The Year 2000:
Owner’s Bottom Line:
Now compare the best case scenario for the low maintenance approach (spends much less than is likely) versus a worst case for aggressive maintenance (spends much more than is likely) versus a worst case for aggressive maintenance (spends much more than is likely).
PLUS: Tens of thousands in energy savings,
The maintenance program now spans thirteen (13) years. Square footage is approximately 220,000 square feet. The cost savings per square foot, per year is close to 10 cents. This is based on making the aggressive program look as cost ineffective as possible. Mr. Firman’s conclusion of 15 cents is probably more realistic.
Assumptions play a huge role in this type of costing and are always subject to challenge. In this article we demonstrate a real situation with real numbers past the ten-year point that is quite common. We use assumptions late that are, on the whole, a worst case for aggressive maintenance. This is done to the point of being ridiculous by not including loss of capital and energy – hard, factual, and substantial losses.
To effectively manage our clients’ roofing assets we must be proactive. To what degree and at what cost are the questions. Try your own numbers with your own assumptions. I strongly believe you will find the aggressive approach will save your client substantial time and money.
It is conservatively accurate to tell building owners that their business decision not to employ an aggressive maintenance program is costing them between 10 cents and 15 cents per square foot, per year. Multiply this times the number of square feet your client owns or manages and show them their bottom line as an annual loss.
NOTE: The best time to start a program is after year one. In 1995 two new roofs (one year old each) under guarantee by two different manufacturers were found to have wet insulation. Read the guarantee for written coverage and typically only the leak will be stopped. Also, the program’s design and the type of equipment is critical and will vary depending on construction. For example, infrared, nuclear, capacitance, and even new monitoring systems are all vastly more beneficial on different systems and conditions. Proper care in selecting even between infrared equipment is needed. Options and recommendations will be discussed in a later article.