Spray foam insulation is an insulation product that is sprayed into wall cavities where it expands to fill the space.  It can be used when building a new home but is more often used as an after market product to add insulation to the attic or other spaces as it is much easier than tearing out walls to add other types of insulation.

This type of insulation comes in two types: open-cell and closed cell.  The closed cell type is typically made from polyurethane and has a higher insulation value than the open-cell type.  When applied, the insulation consists of a liquid with a foaming agent added.  The insulation professional sprays the substance into the cavities within the walls, floors or ceiling.  There the liquid and foaming agent combine and fill every tiny bit of space within the cavity.  This enables the product to also act as a sealant.  One of the main attractions of using spray foam insulation is that it does not shrink or settle like most other forms of insulations so it is an extremely long lasting product.  This type of insulation does tend to cost more than many other types, however, mainly because it must be professionally installed and because of the extreme durability.

I personally have used a consumer made product like this primarily as a sealer and not so much for its insulating properties.  A few years ago, we had a nasty bee problem where a hive of bees had built their nest behind my front stoop.  The front stoop was a poured concrete set of steps and over the years had separated from the front of my house.  This separation wasn’t a huge gap, but it definitely was large enough for the insects to get into.  The main problem I had was that I didn’t notice the problem for at least two years.  I spent a lot of summers wondering why we always had so many bees flying around our home, and low and behold I finally saw what was happening one day while chasing one around.

So to make a long story short, what I did was to wait until evening when the bees were least active.  They “go to sleep” so to speak in that they aren’t flying back and forth on their daily work routes at night and there isn’t as much activity coming and going out of the hive.   I stuffed some of the largest gaps in my concrete steps with old rags in order to fill up some of the space.  I only bought three cans of the spray foam insulating material and wasn’t sure how much I would need.  Once I had stuffed the cracks, I went ahead and sprayed in the foam.   Immediately the foam expanded and protruded back out of the cracks… letting me know that the space had been filled.  It took me about 30 minutes and cost me about 20 bucks in total. And even better,  I did it for the entire front porch and managed not to get stung by any of the critters.

As a follow up during the next two days, I watched closely after the foam spray insulation had completely dried to see if any more bees were able to come or go.  It turns out I did a pretty good job with my first attempt as there were a few lost straggler bees that were trying to get back into the hive, but couldn’t figure out a way to get past my foam spray job.  All, in all this was a perfect application of using this type of foam spray sealant.

If you find you have a need to fill gaps, cracks, or even use this spray foam as an insulator, you can find out a lot more technical details online at the manufacturer websites.   Of course there are also specialty retailers that are also happy to help you pick out the best product for your job. Just remember, when you look online for spray foam insulation, you will find many websites offering information about the products available and how they are installed so make sure you do due dilligence and check more than one site.   You will be able to compare for yourself the advantages and disadvantages of spray foam insulation as a kind of insulation as well as a sealer.