Minimum R Value For Wall Insulation

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.

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. The table below shows what levels of insulation are cost effective for different climates and. 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. This will determine the r values required for different parts of your home.

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

Insulation level are specified by r value. 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 higher the r value the better the thermal performance of the insulation. 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.

Specific insulation requirements of section c402 2 thermal requirements of either. 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 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. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4.

The r refers to absolute thermal resistance. Thickness density and type of materials are some factors that contribute 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. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope.

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 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.