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.