Maximize Roof Service Life

09/01/2013 | By Eric Hasselbusch

Use lifecycle models and cost analysis to raise the ceiling on your roof's value

To ensure that your costs don’t go through the roof, equip yourself with the tools to plan roofing initiatives effectively. Justifying capital funds for these jobs can be challenging, especially when competing for funds with projects that generate revenue for your company.

Because roof investments are rarely justified on the basis of ROI alone, it is important to consider asset management benefits, lifecycle costs, consequential damages, and other potential business risks as part of your funding request.

The following tools and analysis will help you plan effectively, avoid disasters, and justify the sizable investment that many roofing projects represent.

Lifecycle and Cost Analysis
Lifecycle costing gives facility managers a way to evaluate roof projects and management programs based on long-term payback, not just initial costs. It also provides you with additional financial information that can be used to justify roofing decisions and expenditures.

One lifecycle model comes from ASTM E 917, Standard Practice for Measuring Life Cycle Costs of Buildings and Building Systems. The model incorporates variables such as time study period, inflation rate, discount rate, and combined tax rate. Results comparing various scenarios are provided in present net value and equivalent annual value.

To ensure the results are as accurate as possible when using lifecycle costing, the model incorporates building owner input regarding the discount rate and all critical assumptions. Accurate models of roof performance and projected costs should incorporate an initial evaluation of the facility roof(s), discussion with the building’s operators and representatives, and expert insight.

A lifecycle cost model does not replace the human thought process. It is simply another tool you can use to support your efforts in making sound business decisions. In a perfect world, facility managers could compare several lifecycle costs and make the right decision regarding their roofs.

Unfortunately, it is not that simple. A lifecycle cost model doesn’t provide right or wrong answers – it provides information. Each situation and facility is unique. To make the best decision for the specific situation, facility managers and building owners must weigh lifecycle cost information along with other factors such as available funding, location, contaminants, interior sensitivity, and many others.

The quality of the output of a lifecycle study is dependent upon the quality and accuracy of the assumptions and input. As shown in the example on page 55, making a relatively minor change to assumptions and inputs can have a significant impact on the outcome.

Using the provided example, you can equip yourself with a blueprint for how to analyze your situation and put your best foot forward. Replacement, repair, or a simple coating all may be viable options, but the best decision depends on your specific situation.

The model can help you decide which management strategy to take, whether that entails simpler maintenance and repairs or full-scale reroofing.

Replace, Recover, or Coat?
Determining if you should replace, recover, or coat a roof is a typical situation where lifecycle analysis can be useful. In this scenario, the existing roof is 15 years old and approximately 100,000 square feet. The existing roof consists of two layers of modified bitumen and a base sheet over a wood deck. The field membrane, seams, and flashings appear to be in maintainable condition and exhibiting normal weathering. There is no evidence of leaking, but ponding water is impacting approximately 5% of the roof.


Based on lifecycle costs alone, coating the modified bitumen roof immediately appears to make the most economic sense. However, there are some additional factors that should be considered before selecting the coating as the best option.

  1. Are you confident the coating will last 10 years and it can be coated a second time? Long-term performance of a coating depends on coating type, proper surface preparation, and correct application. If not applied properly, the likelihood of reaching 10 years with a coating is remote, especially when coating a second time.
  2. Precautions must be taken to ensure the ponding areas have been addressed as some coatings fail in standing water. These areas will likely require special materials that can tolerate ponding water.
  3. Repairing a coated modified bitumen roof can be more difficult and time consuming than repairing an uncoated roof.

Even if all these factors are adequately addressed, there are still other issues that may impact the outcome and decision-making process. For example, if short-term funds to coat the roof are not available, a facility manager may address emergency leaks as they happen and then replace the roof in five years – or, as seen in the chart below, if it is determined that the replacement cycle can be extended by five years (from 20 to 25), then the replacement scenario is the best option to consider.


A lifecycle model should be used carefully or poor decisions can result. A model doesn’t provide right answers – it simply provides additional information that helps to make informed business decisions.

Pages: 1  2  View All  

Related Coverage

antalya escort
escort antalya
xxx movies ladyhammer casino
18 film izle
ankara escort
replica watches
istanbul escort
British Shorthair Cat
manavgat eskort