Let’s talk about a four-letter word that begins with “F”…..Foam!
My builder, architect, and designer friends and I must have a serious conversation. As your industries strive to build more eco-friendly and energy-efficient homes, many look for foam insulation as one solution. Building trends, like Passive Houses and Insulated Crawl Spaces, use foam insulation in critical areas to improve energy efficiency.
There is just one problem with this. Humans are not the only living organisms that recognize the advantages of foam in our daily lives. Termites and rodents can also be included in that list of organisms, where the problems start. Today, we will talk about how termites invade foam insulation and the problems this creates if we do not address the issue at the construction stage.
The Problem
Termites are estimated to cause $5 billion in damages to buildings every year. Over 15 years ago, the ICF Association recognized this problem with the following statement: “Termites pose a particularly difficult problem, [as] buildings should be insulated for energy savings, yet termites can infiltrate through any insulation and penetrate all but the strongest materials.”
Let me be clear: termites do not eat foam. Using their chewing mouthparts, they tunnel through foam for insulation, saving time and resources within their colonies. By tunneling through the foam extensively, termites find pathways to bypass typical liquid soil treatments and wood frame treatments, rendering them ineffective. So, if we use foam extensively to insulate our buildings, we need to be aware of the locations, risks and challenges termites pose.
Photo of 3-year-old slab on grade home with spray foam insulation Formosan termite damage that had been “treated” with a borate based product.
US Regional Subterranean Termite Activity
Termites are found in almost every area of the United States. However, they are more prevalent in certain areas, and most of the damage termites cause comes from subterranean termites. We can reference the U.S. Subterranean Termite Distribution map to see where the termite threat is greatest.
Noting that the states in “Red” typically have Formosan termite populations raises the threat tremendously when using foam due to the Formosan colony sizes and foraging aggressiveness.
US Subterranean Termite Distribution Map
Termite Risk By Foam Type
It is not one particular type of foam that is at risk. All foam that termites can access is at risk. To name a few areas at risk:
Armorflex foam wrapped around utility pipe penetrations through the slab.
Spray foam insulation (crawlspace, slab on grade walls, attics, everywhere it’s applied)
Rigid foam boards that are used to insulate crawl space or slabs.
Closed Cell foam, Open Cell, EPS, it does not matter. All foam not impregnated with a pesticide is vulnerable to termite attack. This is why it is so important to choose your termite protection wisely.
Photo of Rigid Foam Board with termite tunnels
Foam-Related Termite Protection Options
You have options for protecting against termites, but you need to choose wisely. Most termiticide-based applications will only be effective for 5-7 years before they break down and become ineffective, and none of the termiticides on the market will penetrate the foam to provide any protection.
The other important issue to know is that the foam often provides a path for termites to bypass any termiticide application. It will never be effective if the termites do not get into the termiticide.
On the other hand, physical barriers are protected by cutting off the hidden pathways termites use and making them visible so they can be addressed at a lower cost and more effectively. A barrier product like Termimesh has over 150 profiles to address different construction details (ie. Utility penetrations wrapped with Armorflex foam, insulated slab, brick lug below final soil grade, insulated crawl spaces).
The other advantage of using a physical barrier product is that it is constructed using construction-grade materials and, when installed properly, should provide long-lasting termite protection for your build.
One last reminder for your termite options. Choose a product approved by the ICC that meets the Building Code Standard and has an EPA Establishment Number as a termite device. Not all products are equal, and not all products marketed have tested to the pest control industry standards of a minimum of 5 years of efficacy.
Stay Tuned
Our next few blog posts will examine a Passive House with an insulated slab and another case study on a spray foam-insulated crawl space. Both builds were in known Formosan termite areas. We hope you will join us in these as well. See you on the job site.