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How insulation upgrades can help seal your home from bugs
March 17, 2022 at 7:00 AM
man working in dark attic of house with headlamp for light source

The insulation in our homes keeps them comfortable, cozy, and inviting. Unfortunately, the most common type of insulation is also the coziest and most inviting for pests.

Fiberglass insulation, the kind in almost every wall and attic in America, is a good insulator and is relatively inexpensive. It also attracts pests. For decades, fiberglass insulation has been a favorite of builders and bugs alike!

Fiberglass insulation is fibrous—perfect for making nests—and retains moisture, helping pests thrive. Even when properly installed, it leaves gaps and doesn’t do anything to seal cracks.

What’s a homeowner to do?

The good news is that simple insulation upgrades can seal your home from pests, with the added benefit of significantly improving your home’s energy efficiency. Nobody wants to share their home with pests, and wouldn’t everybody love to save a little money on their utility bills?

Here’s how to seal your home from bugs with insulation upgrades from St. Louis Insulation.

Insulation upgrades

There are three types of insulation that help prevent pests:


Cellulose insulation is mostly made up of recycled plant material and post-consumer paper. It also contains a flame retardant chemical, borate, which also happens to be a potent insecticide. Natural fiber cellulose can be applied over the top of existing fiberglass insulation without losing any of its protective properties, making it a great solution for upgrading your attic insulation. And the borate is non-toxic and safe for humans.

Spray foam

Open-cell spray foam is an excellent pest deterrent. The soft, malleable foam conforms to whatever area into which it is sprayed. It fills every gap, crack, and crevice, and repels moisture, making it uninviting and unsuitable for pests. When properly applied, it creates a solid, impermeable barrier against pests. Spray foam is a great option for tight corners and hard-to-reach areas in attics, basements, and crawlspaces.

Polyurethane foam

Polyurethane foam comes in both flexible and rigid varieties. Both forms are undesirable for pests, because polyurethane foam isn’t plush or fibrous, and therefore can’t be used for nesting. It also conforms tightly to any space, filling gaps and cracks, and doesn’t shrink when it dries, creating a great seal against bugs.

These are the best types of insulation to prevent bugs, and they are also great for keeping your home energy-efficient. Making simple, targeted improvements can reduce heating/cooling costs by up to 40%!

What types of pests can insulation protect against?

  • cockroaches
  • fleas
  • termites
  • beetles
  • ants
  • mosquitos
  • mice and rats

Additional air-sealing

Upgrading your insulation with one of the three types mentioned above will help keep pests from coming through your attic, basement, or walls. But there are other ways they may be getting in. Any place where outside air can creep into your house is an opportunity for bugs to follow.

Check for any small gaps or openings around exterior electrical and water fixtures, and any vents. Use a caulk gun for any small gaps or canned spray foam for any larger openings. Check the seals around doors and windows and replace any weather stripping that is damaged or worn. Make sure window screens fit tightly in their frame and are free from any holes or tears.

Hire the best!

If you’re concerned about how to seal your home from bugs, let us help! Our expert team at St. Louis Insulation is highly-experienced in home insulation, energy efficiency, and air-sealing. We have the experience to identify and treat your home’s most inefficient and vulnerable areas.

Call us at 314-334-0153 today or book an appointment for your free consultation!