Wall Insulation R Value

In the context of building and construction the r value is a measure of how well a two dimensional barrier such as a layer of insulation a window or a complete wall or ceiling resists the conductive flow of heat.

Wall insulation r value.

R value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the warmer surface and colder surface of a barrier under steady state. An r value tells you how well a type of insulation can keep heat from leaving or entering your home. Raycore s 5 1 2 inch thick polyurethane sip panel has an r value of 42. 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. Insulation ratings are measured in r values per inch of thickness. Basics of faced fiberglass insulation from r 13 to r 19. Insulation r values vary based on the type thickness and density of the insulation material.

While wall insulation is limited by the width of the studs different materials provide higher or lower r values. The r refers to absolute thermal resistance. The higher the r value the greater the thermal resistance of the insulation. That s 75 percent more r value for half the price.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. What r value do i need. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation.

Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. 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. Calculating the r value of insulation involves multiplying its thickness in inches by its r value inch. Typically a higher insulation r rating means better climate control and better energy efficiency for your home.

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. For example a wall with 3 fiberglass batting r value of 10 8 11 9 may have an overall r value of nearly 14 because of siding sheathing and drywall. To reach a similar r value with a sandwich panel you would have to purchase their 10 1 4 inch thick panel with an r 40 or their 12 1 4 inch thick thick panel with an r 48 insulation value. R value is a standard unit of measurement for determining among many things how effective your insulation will be.

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.