Spray Foam Insulation R Value Vs Fiberglass

As a benchmark one inch of solid wood has an r value of 1.

Spray foam insulation r value vs fiberglass.

For instance a 5 5 inch wall cavity can be filled with 2 inches of foam and an r 13 fiberglass batt as a cost effective system that seals the walls with an r 25 insulation system exceeding u s. The common denominator among varieties of insulation is the r value. Fiberglass insulation is less than half the price of rigid foam insulation when calculated by r value per square foot. A spray foam rig can cost upwards of 70 000.

Average cost of spray foam vs fiberglass insulation one board foot 12 x 12 x 1 of open cell foam insulation averages 0 45 to 0 80 cents the same amount of closed cell insulation costs between 1 and 2 a square foot of fiberglass costs between 1 30 and 3 50 on average. Available spray foam types include cementitious phenolic polyisocyanurate polyiso and. Open cell foam is soft and spongy impermeable to air but permeable to moisture and according to the doe has an r value per inch ranging from r 3 6 to r 4 3. Once applied closed cell foams become rigid and have an r value range from r 6 to r 7.

Home improvement stores will often rent you a machine to blow in the fiberglass. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Spray foam insulation vs fiberglass r value is about equal for open cell insulation and about double for closed cell insulation per one inch layer. 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.

1 additionally spray foam insulation has a high cost of entry with required training and equipment. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and. For example insulating a 10 square foot wall area to r 15 costs about 3 40 to 4 00 with fiberglass insulation while a comparable r value for rigid foam costs roughly 10. The r value is a measurement of how resistant the product is to heat flow the higher the r value the more heat will be prevented from transitioning through the insulation.

R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. Compare spray foam vs fiberglass insulation costs summary. The r value of fiberglass insulation is approximately 2 2 per inch so much thicker fiberglass insulation is required to achieve the same r value of 38. The installed cost for r13 of spray foam insulation has been shown to be nearly 3 4 times as much for the same r value as fiberglass.