Ceiling Insulation R Value Recommendation

The r value depends on the type of insulation its thickness and its density.

Ceiling insulation r value recommendation.

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. Where you live different climates require different insulation r values. Insulate the garage s ceiling by using the recommended r value for your area as advised by the department of energy s oak ridge laboratory. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.

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. When insulating ceilings in warmer climates or when using higher density materials as little as 8 inches of thickness may suffice. Insulation level are specified by r value. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better.

Basics of faced fiberglass insulation from r 13 to r 19 r value is a standard unit of measurement for determining among many things how effective your insulation will be. See the department of energy s doe ranges for recommended levels of insulation below. The amount of insulation recommended for your home will vary depending on a number of factors. The table below shows what levels of insulation are cost effective for different climates and locations in the home.

When calculating the r value of a multilayered installation add the r values of the individual layers. According to the doe 8 inches of high density batt insulation will provide around an r 30. Foam in place insulation can be injected into walls to reduce air leakage and improve r value. R value is a measure of insulation s ability to resist heat traveling through it.

Foam insulation r values range from r 4 to r 6 5 per inch of thickness 2 54 cm which is up to 2 times greater than most other insulating materials of the same thickness. The r refers to absolute thermal resistance. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. The higher the r value the better the thermal performance of the insulation.

The r value of some insulations also depends on temperature aging and moisture accumulation. Exterior walls if your exterior walls are constructed from 2 by 4 inch studs the most insulation that can go into the wall while retaining its r value is r 13 or r 15 as these are both made to fit a cavity 3 1 2 inches deep.