Flat Roof Insulation Requirements

Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof.

Flat roof insulation requirements.

Cold roofs have insulation beneath the roof deck which is beneath the roofing material. For a 1 inch board equivalent of 6 r value. It is top quality and the most cost effective product for your flat roof. Where insulation is mechanically fixed the fixings must be of sufficient length to.

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. This means that your approach to insulation will differ from a standard pitched roof. Applicable roofing assemblies designers may view unvented attic i e. It depends on where the insulation is installed.

If insulation is installed below the flat roof deck this is called a cold roof. Hot roofs have the roof deck then insulation then the roofing material. Consider geography budget and use for the roof to determine the best option. A cold roof or hot roof.

A note to consider before construction. Attic space enclosed rafter or joist space above normally occupied and conditioned interior space assemblies as an economical arrangement of roofing and insulation materials. See the department of energy s doe ranges for recommended levels of insulation below. You can expect to pay about 55 100 sq ft.

In most cases there will not be a loft in a building that features flat roofing. 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. Insulation requirements for roofs are therefore spread across ibc chapters 12 13 and 15. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines.

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. How much ventilation does a flat roof need. If the insulation has a sufficiently high vapour resistance a separate vapour control layer may not be required and the. The answer depends on the type of roof you have.

We recommend having at least 20 r value worth of material for optimal energy efficiency. The insulation may be fully or partially bonded to the vapour control layer or laid loose. 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. While expensive the best insulation is polyiso rigid foam.