Flat Roof Insulation Requirements

Applicable roofing assemblies designers may view unvented attic i e.

Flat roof insulation requirements.

Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. It depends on where the insulation is installed. Where insulation is mechanically fixed the fixings must be of sufficient length to. For a 1 inch board equivalent of 6 r value.

The answer depends on the type of roof you have. A cold roof or hot roof. 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. Hot roofs have the roof deck then insulation then the roofing material.

Attic space enclosed rafter or joist space above normally occupied and conditioned interior space assemblies as an economical arrangement of roofing and insulation materials. A note to consider before construction. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines. See the department of energy s doe ranges for recommended levels of insulation below.

If insulation is installed below the flat roof deck this is called a cold roof. 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. We recommend having at least 20 r value worth of material for optimal energy efficiency. From there the flat roof system you choose will determine the materials you apply.

It is top quality and the most cost effective product for your flat roof. Insulation requirements for roofs are therefore spread across ibc chapters 12 13 and 15. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. How much ventilation does a flat roof need.

In most cases there will not be a loft in a building that features flat roofing. Cold roofs have insulation beneath the roof deck which is beneath the roofing material. Consider geography budget and use for the roof to determine the best option. While expensive the best insulation is polyiso rigid foam.

You can expect to pay about 55 100 sq ft. This means that your approach to insulation will differ from a standard pitched roof. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. There must be a slope of 1 80 part h of the building regulations regarding drainage state that water should drain to one or two edges waterproofing should extend up the adjacent walls at least.