Minimum R Value For Wall Insulation

The higher the r value the better the thermal performance of the insulation.

Minimum r value for wall insulation.

While wall insulation is limited by the width of the studs different materials provide higher or lower r values. The table below shows what levels of insulation are cost effective for different climates and. 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. 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.

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 is a measure of insulation s ability to resist heat traveling through it. The r refers to absolute thermal resistance. 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. 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. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. Recommended home insulation r values.

Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. Specific insulation requirements of section c402 2 thermal requirements of either. This will determine the r values required for different parts of your home.

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 values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Minimum insulation r value requirements non residential above roof deck. Thickness density and type of materials are some factors that contribute to.

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