I had an opportunity last month to participate in a webinar with a leading roof consultant who turned my idea of roof maintenance upside down. Like lots of challenges in life, I tended to view maintenance to be the “90 percent perspiration” part of the old saying. Yes, you need a good maintenance plan, but your success at holding down costs and extending roof service life mainly involves the tedious work of carefully inspecting a roof and making timely repairs. However, this consultant offered a chart from the CSI Manual of Practice that showed how the early inspiration of planning and designing a roof system may have a much greater effect on cost and service life than the perspiration of the years of maintenance that follow.

Intrigued, I did a little research and found that the idea behind the CSI chart came from a research study conducted over 30 years ago by the late Boyd Paulson, a distinguished civil engineer. Based on his investigation of costs associated with construction projects across the world, Paulson suggested that the “ability to influence costs” follows a typical inverted “S” curve, with most of the potential for cost control occurring very early in the design stages of a project. Figure 1 illustrates Paulson’s concept of this curve of diminishing results.