If you remember, we are discussing the differences between open cell and closed
cell spray foam insulation. Here’s a quick recap of yesterday’s post: R-value is the
ability to prevent the transfer of heat. The higher the R-value number, the better
the insulation works to prevent heat transfer. Open cell spray foam has a lower
R-value per inch than closed cell spray foam. Open cell is an air barrier, while
closed cell is an air and moisture barrier. Finally, open cell spray foam is sponge-
like and moves with the building, whereas closed cell spray foam provides
If you’re wondering what this means in terms of your home, read through the
1. You realize that your 20 to 100 plus year- old home seems cold and drafty in the
winters and hot in the summers. Your friends with newer, larger homes
brag about their utility bills, and yours is double!
Since your home is a bit older, and you live in Southeast Louisiana, it’s likely that
open cell spray foam is a good option for you. While the use of either will
drastically improve your energy efficiency, there are several reasons that make
open cell spray foam optimal:
- Open cell spray foam is moisture permeable (it’s not a moisture barrier).
This means that moisture can pass through it. It seems as though this
might be a bad idea, but it’s not. For example, if your roof developed a
leak, you wouldn’t want the foam holding all of that water and hiding the
problem. That would cause more damage in the long run.
- Also, since open cell foam is more flexible than closed cell foam, when
homes expand and contract due to changes in weather, the foam will shift
and move with it. In some applications, since closed cell foam does not
flex, cracks could develop.
- Finally, open cell foam is less expensive, so it is often a more cost-effective
option for homeowners.
2. You just invested in a metal building where you will store equipment and
have a small office. You are concerned about climate control to preserve
your equipment and, of course, maintaining a comfortable temperature in
your office despite the weather.
Since this building is made of metal, and not wood, closed foam insulation is probably the better option.
- First of all, since closed cell foam is the denser and more rigid of the two, it
adds to the structural integrity of the building.
- Closed cell foam insulation also provides and excellent barrier to moisture, air,
and sound. These sealing properties also protect the your building’s
environment from allergens and moisture accumulation due to the sealing
of any holes, gaps, or cracks that may be present in the building.
These are two pretty specific examples, but we will explore many of the other
applications that can help you maximize the comfort and energy savings that
spray foam can provide.