Flat Roof Insulation Requirements

It depends on where the insulation is installed.

Flat roof insulation requirements.

For a 1 inch board equivalent of 6 r value. 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. Where insulation is mechanically fixed the fixings must be of sufficient length to. Consider geography budget and use for the roof to determine the best option.

If the insulation has a sufficiently high vapour resistance a separate vapour control layer may not be required and the. 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. While expensive the best insulation is polyiso rigid foam.

The insulation may be fully or partially bonded to the vapour control layer or laid loose. Cold roofs have insulation beneath the roof deck which is beneath the roofing material. In most cases there will not be a loft in a building that features flat roofing. From there the flat roof system you choose will determine the materials you apply.

A note to consider before construction. See the department of energy s doe ranges for recommended levels of insulation below. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. Any type of roof from tpo to epdm can be either hot or cold.

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. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines. 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. 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. Insulation requirements for roofs are therefore spread across ibc chapters 12 13 and 15. You can expect to pay about 55 100 sq ft. Attic space enclosed rafter or joist space above normally occupied and conditioned interior space assemblies as an economical arrangement of roofing and insulation materials.

Applicable roofing assemblies designers may view unvented attic i e. The answer depends on the type of roof you have. It is top quality and the most cost effective product for your flat roof. A cold roof or hot roof.