Minimum R Value For Wall Insulation

R value is a standard unit of measurement for determining among many things how effective your insulation will be.

Minimum r value for wall insulation.

Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state local mo missouri 2012 iecc 4 r 25 5 r 25 state only mt montana 2012 iecc 6 r 30. These r value objectives aren t measured through insulation alone though. Thickness density and type of materials are some factors that contribute to.

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. 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. 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. Specific insulation requirements of section c402 2 thermal requirements of either.

Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. While wall insulation is limited by the width of the studs different materials provide higher or lower r values. Minimum insulation r value requirements non residential above roof deck.

Recommended home insulation r values. 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. Fiberglass batts for standard 2 4 walls are now available in low medium and high density products that range from r 11 to r 15. The r refers to absolute thermal resistance.

The higher the r value the better the thermal performance of the insulation. R value is a measure of insulation s ability to resist heat traveling through it. The table below shows what levels of insulation are cost effective for different climates and. This will determine the r values required for different parts of your home.

For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. Insulation level are specified by r value. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4.