During the code hearings for the 2105 International Energy Conservation Code (IECC), an important clarification was added for commercial roofing systems. This clarification features new definitions for re-roofing activity to make it very clear that almost every commercial re-roofing project must be upgraded to the same R-value level as required for a roof installed on a new building whenever the existing roof covering is removed and replaced.

Although this requirement may sound simple, the language used in the code for many years has caused a lot of confusion. Instead of talking about a typical commercial roofing system installed over a roof deck, the old code language referred to the roof deck as “sheathing” and included language referring to a “cavity” located somewhere below the roof. As a result, the code language called for an upgrade in roof insulation for roofs “without insulation in the cavity and where the sheathing or insulation is exposed.” Unfortunately, this language could be very confusing for the local code official.

Instead of attempting to describe the exact conditions of a typical commercial roof replacement within a single sentence in the code, the new code clarification establishes specific definitions for each major type of roofing activity that can occur on a commercial building:

  • Re-roofing. The process of recovering or replacing an existing roof covering.
  • Roof Recover. The process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.
  • Roof Replacement. The process of removing an existing roof covering, repairing any damaged substrate and installing a new roof covering.
  • Roof Repair. Reconstruction or renewal of any part of an existing roof for the purposes of its maintenance.

With these new definitions in place, the task of describing when insulation must be upgraded to the most recent energy code is very simple. First, the new, clarified code language specifically exempts “roof recover” and “roof repair” from the latest insulation requirements. Next, the new language specifically states that “roof replacement” must meet the latest insulation requirements when the roof replacement is applied to the typical above-deck commercial roofing system installed over a conditioned (heated or air-conditioned) space. This new code language is especially important because the re-written code requirement is considered a clarification rather than a new addition to the code. This means that code officials don’t have to wait until the 2015 version of the IECC is adopted in their jurisdiction to start enforcing this requirement.

Because the new re-roofing code language is considered a clarification of existing code language, this is immediately relevant everywhere in the United States where some version of the International Energy Conservation Code has been adopted, as it has here in the Chicago. As a result, there is no longer relief to building owners needing to replace their existing roof system. Under these clarifications by the IECC, roof torn down to the deck will need to comply with the R-values of a brand new roof system. This costs more money, but provides more motivation to the owner to care for and service the current roof system for as long as possible in order to maximize ROI.

NOTE: The depreciation on a new commercial roof still stands at 37 years even though the average roof life of these systems is 17.5 years.

Categories: NIR Blog


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