 # Calculations and Coverage

Calculating the amount of foam you might need for your project can be challenging. There are many factors to consider prior to even doing the math, such as what R value you may be targeting or even just knowing what solution you are trying to provide.

Starting with the basics, The Foam it Green 602 kit is closed cell foam providing an R value of approximately 7 at a cured thickness of one inch. So, if you are shooting for a total R value of approximately 14, then you would want to end up with a cured thickness of two inches. (*It’s best to apply Foam it Green 1/3” wet so that it can expand to 1” cured. For two inches, do this a second time after the first inch has fully cured.)

Let’s look at an example of a wall that is 30 feet long and 8 feet tall. The surface area of this wall is 30’ X 8’ or 240 squared feet. So, if you intend on spraying this surface at a thickness of 2”, then you would multiply the square footage by the thickness. In this case, 240sf X 2” equals 480 board-feet. Wait a second! What the heck is a “board foot” you say? A board foot is a squared foot that is one inch thick. It essentially gives thickness to the two dimensional calculation of “squared feet”. If you were going to spray this 240sf at a thickness of 3”, then it would be 720 board feet (240 X 3).

Regarding the coverage you can get out of a kit, Foam it Green makes it easy by numbering them with the potential board feet they can yield. The Foam it Green 202 and 602 kits have enough foam in them to cover 202 board feet and 602 board feet respectively. So, in our above example, if you needed 480 board feet, you should opt for the Foam it Green 602. If you wanted to go with a third inch, your 720 board feet would take a 602 and a 202.

Let’s look at an example of a wall that is 30 feet long and 8 feet tall. The surface area of this wall is 30’ X 8’ or 240 squared feet. So, if you intend on spraying this surface at a thickness of 2”, then you would multiply the square footage by the thickness. In this case, 240sf X 2” equals 480 board-feet. Wait a second! What the heck is a “board foot” you say? A board foot is a squared foot that is one inch thick. It essentially gives thickness to the two dimensional calculation of “squared feet”. If you were going to spray this 240sf at a thickness of 3”, then it would be 720 board feet (240 X 3).

Regarding the coverage you can get out of a kit, Foam it Green makes it easy by numbering them with the potential board feet they can yield. The Foam it Green 202 and 602 kits have enough foam in them to cover 202 board feet and 602 board feet respectively. So, in our above example, if you needed 480 board feet, you should opt for the Foam it Green 602. If you wanted to go with a third inch, your 720 board feet would take a 602 and a 202. ## Here are a few additional quick tips when calculating what you need:

1. Ignore the studs, rafters, and joists when doing the math. When you apply the foam it will build up a bit next to these edges anyway, plus it really over complicates the calculations.
2. The coverage a kit yields is calculated based on ideal conditions. That means that tank temperature, surface temperature, wet application thickness, spray technique etc. have a lot to do with getting all 602 board feet out of a 602 kit. You should always calculate in some room for error because running short and having to delay the project while you wait for another order of foam can be frustrating.
3. Call us, call us, call us. We do these calculations all day, even the tricky ones like curved Quonset hut roofs and geodesic domes. Don’t hesitate to get in touch if you’d like a second set of eyes on your numbers.