New Roof Insulation Requirements

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.

New roof insulation requirements.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. Energy efficient designs should still be considered when using these systems. Images courtesy simpson gumpertz heger. Insulation level are specified by r value.

You should consider attic or roof radiant barriers in hot climates reflective insulation and foundation insulation for new home construction. Minimum insulation r value requirements non residential above roof deck. General requirements for all low slope roofing systems new and replacement 1. A u value of 0 55 w m k is used for cavity insulation and 0 30 w m k for internal or external wall insulation.

Roof insulation configurations for unvented rafter truss assemblies. Ibc dictates acceptable placement and composition of roofing materials in chapter 15 but describes required thermal efficiency of the roof in chapter 13 which references the international energy conservation code iecc the minimum required thermal resistance varies. Existing buildings requirements are sprinkled throughout the i codes. R value is a measure of insulation s ability to resist heat traveling through it.

Roof replacements shall comply with section c402 1 3 c402 1 4 c402 1 5 or c407 where the existing roof assembly is part of the building thermal envelope and contains insulation entirely above the roof deck. See the department of energy s doe ranges for recommended levels of insulation below. Continuous insulation zones ashrae 90 1 ashrae 189 1 igcc ibc iecc 2004 2007 2010 2013 2016 2009 2011 2014 2012 2015 2009 2012 2015 0 25 1 15 20 2 15 20 25 3 15 20 25 4 15 20 302535 5 15 20 302535 6 15 20 3035 7 15 20 3540 25 8 20 3540 25 minimum r value non residential above roof deck. Iecc 2015 requirements by climate zone 3.

England new dwellings. On new build or replacement pitched roofs the ideal build up would be insulation fitted over and then between the rafters giving a big boost for airtightness image credit. The higher the r value the better the thermal performance of the insulation. Kingspan with a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same.

Consider products that provide both insulation and structural support such as structural insulated panels sips and masonry products like insulating concrete forms. For roofing replacements it is necessary to look at the ibc. Exception can be taken when built up roofing or epdm is justified.