In Roof Leaks, Roof Maintenance, Uncategorized

Alternatively, how not to lose $0.15 per square foot per year on your roofs

I believe it is best to use actual events to prove a point. It beats theoretical events by a long shot. In this month’s “It Pays To Maintain” blog, I like to use a real case study to prove that a proactive roof maintenance program is similar to a good investment. Is a good investment because it pays back more than what was originally invested.

Case history:

The Polygram Facility in July of 1996, the Polygram facility was approaching 20 years of age. Excluding air handling equipment, there had never been more than a couple of minor roof leaks at any given time. The vast majority of the time, the facility was leak free during rain storms due to an aggressive roof maintenance program.

How much benefit was realized from the proactive maintenance program for this building? The answer is a great deal:

Polygram Facility

  • Roof size: 220,000 square feet
  • Cost of aggressive roof maintenance program: $0.03 per year
  • Roof and related costs without a maintenance program: $0.15 per year
  • The annual cost to the owner of not having a roof maintenance program: $54,700 per year

Cost without a roof maintenance program*

  • Year 1                                                                                   $135,000

Tear-off of roof section #2; more than 20% of insulation wet in six locations, ranging from 30 to 120 square feet in size.

  • Year 2                                                                                   $0

Nothing is done. However, wet insulation increases in roof sections #1 and #3

  • Year 3                                                                                   $135,000

Complete tear-off required for roof section  #1.

  • Year 4                                                                                   $180,000

Complete tear-off of roof section #3.

  • Year 5                                                                                   $20,000

Major replacement and repairs for misc.


*Based on a conservative estimate of expansion of existing wet areas (30-120 square feet); assumes (unrealistic) cost advantage of no money spent prior to Year 1.

“The decision not to employ an proactive roof maintenance program is costing owners between $0.10 and$0.15 per sq. ft. per year.”

The decision not to employ an proactive roof maintenance program is costing owners between $0.10 and $0.15 per sq. ft. per year.

—Dennis Firman, P.E., U.S. Air Force

Why roof maintenance worked

The Polygram story begins with its original roof survey, including an infrared scan, that located and defined six wet areas of insulation. Each subsequent year, up to three new wet areas were discovered until the last year, when the number jumped to six.

Each year all wet insulation was 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 30 sq. Ft. The largest one identified was in 1988 at only 120 sq. ft. This means they were repaired while still small.

Based on the facility being approximately 220,000 sq. ft. And the program being provided over seven years, the cost is only $0.03 per sq. ft. Per year. Remember also that this program was started after the roofs exceeded ten years of age. The earlier years are typically much less costly and would pull this aver-age lower still.

This $0.03 per sq. Ft. Number is exactly the estimated cost Dennis Firman suggested based on his experience with more than 600 million sq. Ft. 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 $0.03 number. It is accurate to say the cost of an aggressive maintenance program will fall between $0.03 and $0.04 per year, per sq. ft.

The costly alternative

Firman suggests the choice not to have a maintenance program can cost an owner as much as $0.15 per sq. Ft., per year. Based on this estimate, the owner would be losing $33,000 per year. If only a fraction of this amount is correct, the cost savings more than offset the most aggressive maintenance programs.

At this point, we decided to see what this facility would look like if only patching were done to stop leaks with minimum maintenance. Very conservative estimates were used to paint a best-case scenario for the owner.

Included in the study were actual infrared photos of one wet area taken eight months apart. In that time, the area of wet insulation increased 20%or more. However, to be ultra-conservative, we charted linear dimensions of the wet areas to expand at a rate of only 5% per year. Of course, this comparison is unrealistic in evaluating the true cost to the 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.

B. Wet insulation does not insulate and will cost substantially more through wasted energy dollars. Our client heats and cools the facility. Ask yourself: What effect would several hundred or thousand square feet of uninsulated roof area have on your monthly bill?

C. Structural concerns arise due to water weight gain and corrosion of structural components. This adds remedial cost and becomes a potential safety issue.

Owner’s bottom line

Now, let’s compare the best-case scenario for the low maintenance approach versus the worst case for aggressive maintenance: low maintenance: $470,00 versus aggressive maintenance at $196, 500. The savings equal to $273,500. There are also tens of thousands in energy savings, return on capital and more.

With a maintenance program spanning 13 years and square footage of about 220,000 square feet, the cost savings per square foot, per year is close to $0.10. This is based on making the aggressive program look as cost as ineffective as possible. Firman’s conclusion of $0.15 is probably more realistic.

Assumptions play a huge role in this type of costing and are always subject to challenge. To effectively manage your roofing assets, you must be proactive. To what degree and at what cost are the questions. Try your own numbers with your own assumptions. You will likely find the aggressive approach will save you substantial time and money.

It is conservatively accurate for us to tell building owners that their business decision not to employ an aggressive maintenance program is costing them between $0.10 and $0.15 per sq. ft. Per year. Now, multiply this times the number of square feet you own or manage and show this bottom line as an annual loss. It’s a powerful argument to start a formal roof maintenance program today.

Update: A few years ago, my North Carolina client initiated recovers for all of his roofs. They were all past 20 years of age and never experienced more than a few minor leaks in any given year thanks to an aggressive roof maintenance program. At the time of recovery, no wet insulation was found, and the metal deck remained structurally sound.

So, what do you think? Does it pay to maintain? Let me know your thoughts.

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