What foam board has the highest R-value?

Polyisocyanurate: Known as polyiso for short, polyisocyanurate foam has the highest R-value per inch (R-6.5 to R-6.8) of any rigid insulation. This type of rigid foam usually comes with a reflective foil facing on both sides, so it can also serve as a radiant barrier.

What is the R-value of rigid foam board?

Rigid foam R-values range from R-1 for 1/4-inch thick sheathing panels to R-15 for 3-inch thick panels. R-value is not entirely a function of the thickness of the material, as the facing material and type of foam used will affect the R-value of the material.

What insulation has highest R-value?

Vacuum insulated panels have the highest R-value, approximately R-45 (in U.S. units) per inch; aerogel has the next highest R-value (about R-10 to R-30 per inch), followed by polyurethane (PUR) and phenolic foam insulations with R-7 per inch.

What is the difference between pink and blue foam board?

Both are manufactured using the same process and contain similar chemical components. The two products also have the same insulating power. However, blue foam boards are manufactured by Dow Chemical Co. whereas the pink foam boards are manufactured by Owens Corning company.

What is the thickest foam board insulation?

The thickest foam board insulation goes up to 6 inches thick, but needs to be custom ordered. Standard thicknesses available for most foam board insulation ranges from 1/4-inch to 2 inches, depending on the type. Obviously, the thicker the foam board insulation, the better it will be at insulating your home.

Busting R-value insulation MYTHS

What is the thinnest insulation with highest R-value?

Aerogel insulation offers the highest R-value of any insulating material at less weight and thickness—ideal for construction, refineries, pipelines, and thin-gap thermal barriers.

What is the R-value of 1 inch Styrofoam?

STYROFOAM extruded polystyrene insulation is rated at an R-value of 5.0 per inch at 75°F.

Which R-value is best?

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.

What is the R-value of 2 rigid foam?

With an R-value of 13.1 for a 2" thick sheet only two 2" sheets are required to achieve R-25. 2. Extruded polystyrene or XPS (foam is usually pink or blue) XPS has an R-value of 5 per inch of thickness requiring 5" of insulation to achieve R-25.

Which board is best for insulation?

Polyurethane (PUR) is one of the most efficient insulation materials on the market. PUR is available in the shape of insulation boards or foam. However, the boards have a better insulation value than the foam variant. Moreover, these boards guarantee a certain thickness in advance and nothing has to be taped over.

What is the strongest foam board?

Gator Board is an extruded polystyrene foam encased between layers of a melamine and wood fiber veneer. Gatorfoam / Gator Board has a much harder outer surface than other foam core boards and resists warping.

What is the R-value of Foamular 250?

(1) “R” per inch: 5.0 (at 75°F mean temperature).

Does foam board insulation need a vapor barrier?

Foam insulation usually does not require a vapor barrier. For some foam insulation types, such as closed-cell spray foam and foam board insulation, the insulation itself stops the movement of most water vapor.

What is the R-value of R Tech InsulFoam?

InsulFoam EPS has R-values that vary depending on temperature and the density of the product installed. For instance, our standard R-TECH, sold in home improvement stores, has an average R-value of about 3.9 per inch at 75°F.

Does concrete have any R-value?

Concrete has a low R-value. Concrete by itself has a very low R-value, a measure of thermal resistance. Its insulation value comes primarily from using it in thick slabs, and hence isolating the insulated space from thermal fluxes in the environment.

What is the R-value of aluminum foil?

Most brands of foil-faced bubble wrap are only 3/8 inch thick or less, and have an R-value of only 1.0 or 1.1.

How thick is r30 insulation?

8¼ ” thick, R-30C EcoTouch® Thermal Batt insulation prevents moisture damage and helps assure long roof life by providing 1" of ventilation air space between the insulation and roof deck. Easy Installation R-30C EcoTouch® Thermal Batt insulation is easy to handle and install.

What is the highest R-value insulation for a 2x4 wall?

Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.

What is the most efficient insulation?

Fiberglass insulation still allows for airflow into the attic. Spray foam insulation is the most energy-efficient insulation to create an air barrier in the attic. Certain spray foams can expand up to 100 times its original size, so it fills all of the nooks and crannies in the attic.

Does drywall have an R-value?

Drywall, for instance, has an R-value of about R-0.5 for its half-inch thickness. This is minimal when you consider that filling a 4-inch-thick wall cavity with insulation increases the R-value to about R-15.

What is the R-value of 6 inch Styrofoam?

One common use of extruded polystyrene foam board is for foundation insulation panels. Polyiso (Polyisocyanurate). This is an even more dense and more expensive foam board insulation. It provides an R-value of 6 per inch of thickness and often comes foil-faced to help reflect radiant heat.

Which side of foam board insulation faces out?

The reflective side of the board should be oriented to the exterior and the non- reflective white side should be oriented to the interior. EXCEPTION: If vinyl siding is to be installed over AP™ Foil- Faced sheathing, install foam boards with the white nonreflective side toward the vinyl siding.