Roof Insulation R Value Code

State applicable energy ashrae zone.

Roof insulation r value code.

R value measures how well certain building insulation materials can resist heat. Tapered insulation is the most common method for creating a slope on a low slope roof but frustratingly neither code addresses compliance for tapered systems. Know exactly how much you need with our project calculators. State applicable code ashrae zone minimum r value state local al alabama 2015 alabama commercial energy code 2 r 25 3 r 25 state.

Insulation level are specified by r value. Energy codes and roofs. These energy code r value requirements change from state to state and even city to city. Recommended home insulation r values.

When determining how much insulation you need don t guesstimate calculate. Minimum r value non residential above roof deck 19727 57th avenue east puyallup wa 98387. R value is a measure of insulation s ability to resist heat traveling through it. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.

In addition the common belief that an average r value is just as good as the code requirements is just that a common belief not a fact. 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. See the department of energy s doe ranges for recommended levels of insulation below. While the r value for a material is typically given per inch the rsi is typically given per millimeter so please be aware that the r values and rsi values for the materials in the following table are not for equivalent thicknesses.

The table below shows what levels of insulation are cost effective for different climates and. The higher the r value the greater the insulation performance. Types of roof insulation. The higher the r value the better the thermal performance of the insulation.

If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used to maintain a consistent total sheathing thickness.