Minimum R Value For Wall Insulation

The values in this table can also be used as a guide when installing insulation into alterations and additions or retrofitting existing homes with no insulation.

Minimum r value for wall insulation.

It should be noted that these are minimum values only and that upgrading your insulation to a higher material r value can provide a better level of the resistance to heat in your home. The whole construction is measured taking into account additions to the r value like the inherent r value of things like brick walls as well as subtractions caused by windows or any other. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. While wall insulation is limited by the width of the studs different materials provide higher or lower r values.

Specific insulation requirements of section c402 2 thermal requirements of either. The r refers to absolute thermal resistance. The higher the r value the better the thermal performance of the insulation. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better.

The table below shows what levels of insulation are cost effective for different climates and. 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. R value is a standard unit of measurement for determining among many things how effective your insulation will be. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4.

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. 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. Minimum insulation r value requirements non residential above roof deck. R value is a measure of insulation s ability to resist heat traveling through it.

Thickness density and type of materials are some factors that contribute to. 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. 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.

These r value objectives aren t measured through insulation alone though. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Recommended home insulation r values.