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Is Spray Foam Insulation Pest-Proof?

November 22nd, 2023

5 min read

By Kilian Agha

You have probably dealt with pest infestations at some point during your life. You may have heard mice scurrying in your attic during childhood and have memories of setting traps. Perhaps you face regular ant infestations in your current kitchen. Dealing with pests can be an irritating nuisance that keeps your home from being comfortable.

As you consider insulation for your project, you wonder if spray foam is pest-proof. Can spray foam stop the potential onslaught of invading critters?

You are not alone in hoping your insulation can play a role in keeping out bats, mice, and insects. At South Central Services, we have installed spray foam insulation in hundreds of homes. Many homeowners we speak with want to know if spray foam can help with pests, whether it's bats in their attics or spiders in their basements.

By the end of this article, you will understand:

  • Why no insulation is entirely pest-proof
  • How spray foam insulation can deter a variety of pests

Don't have time to read right now? Check out everything you need to know at a glance.

No Insulation is Pest-Proof

No insulation material is 100% pest-proof. Pests are resourceful and can exploit even the tiniest openings to invade your home. While insulation alone cannot prevent pest infestations, it can play a role in pest control.

Effective pest control strategy involves regular inspections, proper sanitation, and professional pest control services when necessary. Insulation can contribute to pest defense, but it is not a standalone solution for a pest-free home.

Let's examine the two primary questions to consider when examining the pest control abilities of an insulation product.

1. Will This Insulation Stop Critters From Entering My Home?

Some pests come inside your house where you can see them. Insects are a great example. You may have spiders in your basement, ants on your counter, or stink bugs fluttering near your windows. Small pests can find their way inside using a tiny crack or crevice. However, if you seal up the small openings within your home, critters will have more difficulty getting inside.

Spray foam insulation is the only insulating material to create a seamless, airtight seal. Other insulations need help from additional air-sealing products to close off those entry points. If you're considering more affordable insulations like fiberglass or cellulose, air-sealing before installing insulation can increase your defenses against pest infestations. Purchasing and using an air-sealing product will raise the insulation cost but will also do a better job of keeping out spiders, ants, and stink bugs.

2. Is This Insulation Material Ideal For Nesting?

While some pests are easy to see, others stay primarily inside your walls. You may not see rodents running around your floors, but they can still find a cozy place to live within your home. Insulation materials that are ideal for nesting invite rodents to become unseen pests.

Generally, insulations that tend to be fluffy or blown-in can be an ideal nesting material. Unless these insulations are densely packed, rodents can easily carve a nest into the walls. Insulating with fiberglass or cellulose does not guarantee rodent infestations, but it is worth considering. Making a pest-control strategy is a wise consideration for homes with these insulation types.

How Spray Foam Prevents Pest Infestations

The unique properties of spray foam insulation allow it to stop various common critters in southern Pennsylvania. Let's examine how spray foam performs in the cases of snakes, rodents, and insects.

How Spray Foam Stops Snakes and Bats

Snakes and bats are larger pests, but they will still try to squeeze through cracks and crevices in your home. These critters also seek to create nests in temperature-controlled homes. For bats, the main entry point is your attic. Snakes can find their way inside through your home's basement or ground level.

A bat sitting on a rock.

Spray foam insulation can seal off the entry points in your attic, basement, and exterior walls. The insulation expands in place and creates that airtight seal.

While snakes and bats can still find their way inside if determined enough, spray foam insulation is not an ideal nesting material.

Closed cell spray foam can be installed in attics, basements, and exterior walls. Closed cell has a firm and rigid cell structure, which would be challenging to dig through or remove.

Open cell spray foam is a less-rigid foam that can be used in attics and exterior walls. Compared to closed cell, the cell structure of open cell makes it easier to disturb. However, neither type of spray foam is an appealing option for nesting.

How Spray Foam Stops Rats and Mice

Rodents are smaller than snakes and bats. Rodents also make a habit of living anywhere within your home. Attics, basements, spare rooms, cardboard boxes, inside of furniture: no area of a home is off-limits to a persistent rodent. Unfortunately, these critters can also cause significant damage. Rats and mice love to make nests and destroy things in the process.

A mouse outside in the dirt.

Spray foam insulation creates an airtight seal, closing off many avenues that rodents would otherwise use to enter your house and crawl space. As discussed in the snakes and bats section, spray foam insulation is not a good nesting material. Additionally, spray foam doesn't serve as a food source, making it less attractive to rodents.

A determined rodent will find a way inside. However, spray foam is one of the best initial defenses against rodent infestation compared to other insulations.

How Spray Foam Stops Insects

Insects are the smallest of pests. Ants, spiders, stink bugs, pincher bugs, and thousand-leggers are all examples of insects we hate to find in our homes. Since insects are so small, they can find their way inside through almost any entry point.

An ant on a piece of wood outside.

Stopping insects is trickier than the other pests we have discussed so far. Insects can sneak inside through cracks and crevices, but can also enter our homes through plumbing. No insulation product can address bugs using pipes, but choosing the right insulation can stop bugs from crawling through walls, ceilings, and floors.

With spray foam insulation's airtight seal, tiny entry points are blocked for these insects. Insulating with spray foam does not guarantee you'll never deal with another spider or see another ladybug on your windowsill. However, using spray foam insulation, you can narrow down areas where bugs enter and make your pest control strategies easier.

Is It True That Termites Love Spray Foam Insulation?

You may have heard that termites live in or eat spray foam insulation. Spray foam is not a food source, but termites can burrow through spray foam insulation. If your property has faced termite infestations in the past, you can still install spray foam in your attic, basement, or crawl space. However, it will be vital to maintain your pest control strategy after insulating.

Installing spray foam insulation will not invite or attract termites. Much like every other pest we have discussed, if a critter wants to find a way inside, it will. Because no insulation product is pest-proof, we always recommend a comprehensive strategy to support your insulation.

The Bottom Line About Spray Foam and Pest Infestations

No insulation alone can prevent pest infestations, but spray foam insulation has built-in features to help prevent various pests. Whether you're trying to avoid bats, snakes, rats, mice, or insects, spray foam insulation offers more pest prevention than insulations like fiberglass and cellulose.

Spray foam insulation is not an ideal nesting material or a food source. With its airtight seal, the smallest of crevices can be sealed off. In our experience, our customers face fewer pests with spray foam insulation than with traditional insulations.

If you continue struggling with unwanted critters, we recommend contacting a pest control expert. While insulation is part of a pest control strategy, regular inspections and professional pest control services play a more significant role.

Now that you understand how spray foam and pest control work together, your next step is to:

Kilian Agha

Kilian has co-owned and operated South Central Services for 8 years. He is passionate about community involvement. In his spare time, he enjoys being with his family, playing ice hockey, and going fishing with friends.