7 Best Caulks to Keep Bugs and Insects Away from Your Home

Bottle of caulking and caulk gun used to repel bugs and insects

You may expect to see a fly or mosquito buzzing around outside your door, but what happens when you start to see bugs and insects crawling around inside? No one wants an infestation in their home, and one of the easiest ways to defend against it is by making sure nothing can get in.

The best way to keep insects out is by caulking the holes and gaps they use to move indoors. These can be spaces around windows, doors, and pipes. The best way to fill these spaces is to use a silicone or acrylic latex caulk, depending on if you plan on painting it and if you need it to be waterproof.

Interested in hearing more about why (and how!) to caulk your home and prevent pests from entering? Read on to learn all this and to see the tools and products we use to secure our own homes from bugs and insects.

Key Takeaways:

  • Bugs and insects typically make their way indoors through small cracks and openings in our homes.
  • Caulk is an easy-to-use material that can seal the entryways where bugs and insects are getting inside.
  • Silicone and acrylic latex caulk are the best types of caulk to use to seal your home against bugs and insects.

* This post contains affiliate links.

Why Do I Need to Keep Bugs Out?

Other than the general “ick” factor of seeing an unexpected insect scurry across your floor, there are plenty of other reasons why you don’t want to share your space with other critters. Bugs may leave behind waste, get into your food, or even chew through important structures in your home.

And to make things worse, if you have one bug, you might find others moving in behind it. Insects often feed on other pests and may enter your home looking for an easy food source, or they may reproduce and compound your issues.

The United States Census Bureau found that about 14 million homes report having cockroaches each year. The US Department of Agriculture reports that termites cause around $40 billion yearly in damages. Needless to say, having bugs and insects is a major problem around the world!

By pest-proofing your home, you ensure that you stop bugs from ever getting inside in the first place, preventing many of these problems from developing. Check out our article on 9 Different Ways That Spiders Get Into Your Home to learn more about how critters sneak in!

Will Caulking Really Keep Bugs Out?

Brown marmorated stink bug (Halyomorpha halys) insect animal near the home

Here’s the good news: Caulk, if applied properly, can close off many of the major avenues that pests use to get indoors. Caulking comes in a variety of types that can fit any need based on where the crack or gap is located around the house.

By the way, caulk is just one way to keep bugs and insects away. You can read about the other things to do if you find stinkbugs in your house.

The Type Of Caulk Matters

It’s important to know that many different types of caulks and sealants exist. Their use depends on what material the caulk is applied to (such as tile, around windows, or even in concrete), as well as whether the caulk may get wet in the future.

Caulking Will Seal Gaps Effectively

When used correctly, caulk can completely seal gaps, creating an effective and lasting barrier against even the most tenacious of pests. Denying bugs entry from the outdoors can help stop your pest problem before it starts. It’s the most effective way of preventing bug and insect issues in your home.

Most Bugs Come Inside During Weather Changes

Most pests come inside with big weather changes (particularly at the start of the fall season), so taking steps now, no matter what time of year it is, can help you in the future. Ladybugs, stinkbugs, and spiders seem to be the big ones for migrating indoors in the fall, but there are plenty more that will sneak inside given the opportunity.

Placement Of Caulk Is Key

Before you start caulking, you’ll want to do a thorough inspection of each room of your home to determine where bugs may be getting in.

Here are some common places for gaps that you may want to take a look at:

Location in HomeDescription of Entry for Bugs and Insects
Window and door framesBugs can enter through gaps in the weather stripping or around the edges of windows and doors.
Cracks in wallsInsects can find their way inside through small cracks and crevices in the walls, especially in older homes.
Vents and exhaust fansBugs may enter through vents and exhaust fans if they are not properly sealed or have damaged screens.
Soffits and eavesInsects can gain access through gaps in the soffits and eaves of the house, especially in attics and roof spaces.
Plumbing and utility openingsBugs can enter through gaps around pipes, cables, and utility penetrations, where they find their way inside through small openings.

These are all spaces that may already have caulk that is peeling away, or they may not have been caulked in the first place, leaving the door open for unwanted guests. Unlike larger pests, bugs can squeeze through even the tiniest of cracks, so even if a gap doesn’t look that big, a bug or insect can still find their way inside.

That’s why it’s so critical to thoroughly look through every area of your home.

7 Best Caulks To Keep Bugs And Insects Out Of The House

sealing cracks around windows with caulk to keep bugs and insects away

We’ve already discussed why you need to select a waterproof caulk and mentioned that it’s important to choose a caulk that will adhere to the material you’re working with (otherwise it won’t stick to gaps and cracks!). But there are even more considerations for the type of caulk you use.

To help make your decision easier, we’ve listed out our seven favorite types of household caulks to use below. Each one has been selected because it represents a different type of caulk that may fit your needs.

Always read the manufacturer’s instructions for application, dry times, and any required safety equipment. Following these directions gives you the best chance at successfully using the product. Not only that, but the proper application will help the caulk last a long time, preventing you from having to fill gaps again in the future.

1. Silicone Caulk

This is likely what most people think of when they hear “caulk”. It’s a white or clear product that is often used around bathroom fixtures, kitchen sinks and faucets, and other areas that may see a lot of water.

It can be used indoors or outdoors, and it lasts longer than most of the other types of caulks on our list (like the other popular type, latex/acrylic caulk).

The downside? It can’t be painted, so if you’re looking for something that can be touched up to better blend in, this caulk is not the one for you. Our favorite type is the Gorilla White 100% Silicone Sealant Caulk because it dries and is waterproof in just 30 minutes.

2. Acrylic Latex Caulk

Although not waterproof, this caulk is paintable, and any mess-ups or drips can be easily cleaned up with water before drying. It’s a good option if you’re looking to seal gaps along baseboards and molding, but it’s a poor choice if you need to caulk bathroom fixtures or areas of plumbing. 

The only other problem with acrylic latex caulk is that it is less flexible than silicone and does not last as long before needing to be redone. Our favorite brand is the 10.1 oz Dap 18065 White Alex Painters Acrylic Latex Caulk. Dap is a well-known and popular brand of caulk, known for its quality product and professional-looking caulks.

3. Sealant Blend

For large gaps, you typically need to install a backer rod unless you’re using Sashco Big Stretch Acrylic Latex High-Performance Caulking Sealant. This fantastic product is a blend of several different ingredients that allows it to fill cracks up to 2 inches wide.

Even better, it’s more flexible than most other caulks, it is water-resistant, and it adheres to almost all materials, including concrete, tile, and wood.

4. Concrete Sealant

If you’re caulking masonry, concrete, or foundation work, you won’t be able to use traditional silicone or latex blend caulks. These products weren’t made to stick to concrete, so you’ll need a specific concrete sealant like Sikaflex Crack Flex Sealant.

This caulk is extremely elastic and waterproof, and it can be painted like latex.

If you use regular silicone or latex caulk on concrete, you run the risk of the product not sticking and peeling off the surface, reopening gaps. So it’s important to use the correct type of sealant for the crack you’re attempting to fill.

5. Insect Repellent Foam

Although not a true caulk, insect-repellent foam is a great option when you need a product that will fill large gaps, is water-resistant, and can insulate against air and moisture.

Even better, foams like the Great Stuff – Pro Pestblock Insulating Foam Sealant will not only block all sorts of bugs but will also discourage rodents that may try to sneak into your home. It does this by containing a bitter ingredient that pests of all sizes will avoid.

6. Low Odor Caulk

If the smell of caulk bothers you or your loved ones, you may look for a product that is specifically low odor. We love BioSeal Clear Silicone Caulk Sealant General Purpose, because not only is it odorless, but it’s moldresistant and waterproof, making it a great option for your bathroom or kitchen.

Avoid using this product in outdoor spaces though, as it can freeze in extreme temperatures, shortening the overall lifespan of the caulk or making it fail prematurely.

7. Acrylic Silicone Latex Blend Caulk

This caulk is the best of both worlds! The silicone components mean it is waterproof, and the acrylic ingredients allow it to be painted. It’s also made to last, meaning you don’t need to worry about reapplication anytime soon.

We like the Red Devil Duraguard Kitchen & Bath Siliconized Acrylic Caulk for our kitchens and bathrooms.

How To Seal Cracks to Keep Pesky Bugs Away

Person applying silicone sealant with caulking gun to keep out bugs

Use A Backer Rod For Large Gaps

For most gaps, you can simply apply caulk to fill them. But if you find spaces larger than ¼ inch, you’ll need to place a backer rod in first and then use caulk. Otherwise, you risk the caulk leaving empty spaces behind that can still let in bugs.

So, what the heck is a backer rod? It’s basically just a flexible piece of material that helps reduce the amount of caulk used. Backer rods can be made out of wood or foam like this M-D Building Products 1/2-Inch by 20-Feet Backer Rod.

Pay Attention To The Surface Type

Whether you use a backer rod or not, take a look at the material the caulk will adhere to and note whether the caulk may be exposed to water.

Some caulks are waterproof or water-resistant, and some are not. Select the correct type based on these parameters. Generally, any caulking in the bathroom, much of the kitchen, and any outdoor caulking will need to be waterproof.

You can read about the insects and bugs that crawl up your drain for more information about bugs in the bathroom and kitchen.

Use A Quality Caulking Gun

Before you begin, you’ll need to buy quality caulk, but you’ll also want a good, comfortable caulking gun like the Newborn Drip-Free Smooth Hex Rod Cradle Caulking Gun. Using a caulking gun can help make caulk application easier, meaning a better, continuous line of sealant that is more likely to fill a gap and look good.

Clean The Surface Before Application

Next, thoroughly clean the surface where you’ll be applying the caulk. Sealant and caulk products need a clean, dry area to adhere to, otherwise, they may not stick or may later peel out of the gap you want to fill.

You may also want to wear gloves or use eye or mask protection if you’re particularly sensitive to strong chemical odors.

Apply The Caulk And Smooth It Out

To apply caulk, begin by trimming the tip of the tube off at a 45-degree angle. Place the tube in the caulking gun, and place the tip in the gap or crack you’re meaning to caulk. Squeeze the trigger and slowly guide the caulking gun along the gap, placing a continuous bead about a ¼ inch wide as you go.

Next, you’ll want to smooth the caulk to improve the appearance and make sure it completely seals the crack. To do this, you may use a wet finger to wipe along the bead of caulk and smooth it out (clean your finger on a paper towel frequently to avoid product build-up).

Or, you may prefer to use a caulking tool, like the YOBZUO 3 in 1 Silicone Caulking Tools, which will make the job even easier and produce a more professional-looking finish.

One of the most important parts of applying caulk is waiting until it is fully dry before painting or allowing water to come in contact with it. It’s important to read the instructions on the specific tube you are using, as some caulks may dry in as little as 30 minutes, while others may need to cure over a day.

Can Bugs Actually Eat Through Caulk?

The answer here may surprise you, and that is that it depends! If you’re using latex, silicone, or another sealant, it’s not likely that pests will chew through as it dries fairly hard. Any bug trying to get in will probably try to find an easier path. Not to mention, caulk doesn’t make for good insect food!

However, there are several eco-friendly or “natural” caulks that may not be as strong as traditional latex or silicone-type products that bugs may be able to eat through.

The exceptions to this rule, of course, are termites and carpenter ants. They may eat through a variety of building materials. These bugs will likely not be discouraged even with sealed gaps, and appropriate treatment should be used to take care of these types of pests.

Check out our guide on simple tips to keep termites from revisiting to see how to keep these destructive pests away.

What Else Can I Put Around My House to Keep Bugs Away?

There are a few different options for natural insecticides that are safe to use in your home and around your family. These include powders and sprays.

Powders

Powders like Ecoxall Boric Acid Fine Powder are natural insecticides that can be used around the perimeter of your home. Or, you may want to try HARRIS Diatomaceous Earth, a powder made from ground fossilized algae that can be sprinkled directly on the floor or in areas where bugs are known to be.

Powders work by drying out bugs and insects, which depend on moisture to keep their exoskeletons intact. Diatomaceous earth contains tiny, sharp fossils that cut into a bug’s exoskeleton, drying them out.

Our guide on the best pill bug powders can hep you zero in on a powder that will work best for your specific situation.

Sprays

Sprays are a great option if you want to target specific areas. Some sprays contain chemicals that can eliminate bugs, especially pyrethrins, while others rely on scent-based deterrents.

Mighty Mint’s Insect & Pest Control Plus can be used inside or outside the home. It uses the power of peppermint and gerniol, two ingredients that are well known for repelling bugs and other critters.

Target areas like around the foundation, near doorways and windows, and in any outdoor area you want to repel bugs from. We have a fantastic guide on the best centipede sprays here!

Avoid Foggers

You may be tempted to use a fogger-type product to clear a room of any pests, but this should not be your first choice. You should first try to pest-proof the room by sealing gaps, then using bait or traps or targeted application of pesticides before trying a fogging device.

If you do decide to use additional products for your bug issues, you’ll want to make sure they’re labeled for in-home use if applied inside.

Integrated Pest Management

Getting rid of bugs is not just about what you can put into your home but also what you should keep out of it! Remove garbage, food, or liquid spills and seal food securely to keep food and water sources away from insects. You may also need to use special insulation treated with boric acid to stop your problem once and for all.

Whatever products you decide to use, make sure that you follow directions carefully and that you dispose of whatever you’re using safely.

Read more about the things that attract ladybugs to your home for more information on eliminating bug and insect attractants.

In Conclusion

Caulk is an excellent solution if you need to seal small holes and gaps around the home to dissuade bugs and insects from coming inside. To recap, our 7 best recommended caulks include:

  1. Silicone Caulk – Waterproof and good for outdoor applications. Can’t be painted
  2. Acrylic Latex Caulk – Good option for baseboards and molding. Not waterproof. Can be painted
  3. Sealant Blend – Use for larger holes
  4. Concrete Sealant – Great for masonry, concrete, and foundations
  5. Insect Repellent Foam – Good to repel bugs and resists moisture and mold
  6. Low Odor Caulk – Best for those sensitive to chemical smells
  7. Acrylic Silicone Latex Blend – Waterproof and can be painted

With the right kind of caulk and proper application, you can seal the entrances to your home effectively to help prevent bugs and insects from entering. Combined with good food storage techniques and careful application of natural insecticides, you can mount a solid defense against any current or future infestations.

That said, even the most diligent homeowners can find themselves overwhelmed with a bug infestation. In these cases, use our nationwide pest control finder to connect with a pest control specialist! They’ll help you get rid of your bug problem and keep them out for good.

References

Dent, D., & Binks, R. H. (2020). Insect pest management. Cabi.

Klotz, J. H., Greenberg, L., Shorey, H. H., & Williams, D. F. (1997). Alternative control strategies for ants around homes. J. Agric. Entomol, 14(3), 249-257.

Peterson, C. J., & Stout, D. (2009). The Chemistry of Household, Structural and Residential Insect Management.

Wimmer, E. A. (2005). Eco-friendly insect management. Nature biotechnology23(4), 432-433.

How to pest proof your home in under a day e-book by Zack DeAngelis

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 Take a look at my guide on Pest Proofing Your Home In Under a Day! I get into the nitty-gritty on the most common types of pests you’ll see on your property including BOTH insects and wildlife, along with the specific signs to look for regarding any pest you have questions about.


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