3 Best Caulk Products for Air Sealing Your Home

Air sealing is one of the most effective ways to keep cool or warm air in your home throughout the year. It’s also an effective way to keep bugs and water runoff out.

When it comes to air sealing, caulk is one of the most popular ways to do it. But what differentiates caulk from other strategies? And which caulk products should you get to air seal your home?

In this article, we’ll be looking at the 3 best caulk for air sealing and how they can improve your home.

Best Caulk for Air Sealing

Our picks for the best caulk for air sealing are:

There are three types of caulk that’s best suited for air sealing: latex, expandable foam, and butyl-rubber. Let’s take a look at the best product for each of these categories to find the best caulk for you.

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Dap Alex Painter’s Acrylic Latex Caulk

Best Latex Caulk for Air Sealing

Latex caulk is sometimes known as acrylic latex caulk and is excellent for using against drywall, wood, and masonry. You can fill in gaps in crown moulding and baseboards with latex caulk as well.

In terms of the best latex caulk out there, there’s hardly a better choice than the DAP Alex Painter’s Acrylic Latex Caulk.

The DAP caulk adheres and dries in 2 hours and can last for up to 10 to 15 years. It’s perfect for setting door frames in place and sealing subfloors at the bottom of a door frame as well.

If you need to quickly fill space between drywall, doors, or windows, this caulk is the best option.

Expandable Foam

DAPtex Plus Foam

Best Expandable Foam Caulk for Air Sealin

Expandable foam caulk uses polyurethane spray foam insulation that can expand and fill up larger gaps and holes. You might use it around leaky electrical outlets, pipes, and window jambs.

The DAPtex Plus Foam is one of the best and most affordable expandable foam caulks out there. If you need to seal up any of the spaces above or keep pests out of your home indefinitely the DAPtex is the way to go.

It’s paintable and won’t leave a mess in your home. It can also dampen sound for a little extra soundproofing inside the house.


Flex Shot Rubber Adhesive Sealant Caulk

Best Rubber Caulk for Air Sealing

Caulk doesn’t have to be used exclusively for indoors – it works just as well in exterior settings too. If you need to seal up aluminum, metal, concrete, mortar, plastics, or rubber materials outdoors, butyl-rubber caulk can get the job done.

The best and most affordable rubber caulk out there is the Flex Shot Rubber Adhesive Sealant Caulk. This reliable caulk is the perfect choice for home improvement projects where you need to cover up smaller holes that might leak air into the home.

It can expand to fill up huge cracks and holes. The Flex Shot also comes with its own tube, negating the need for a caulk gun.

Why You Should Air Seal

But why should you even bother air sealing? If you have proper insulation and ventilation installed isn’t that enough?

Not necessarily. Think of your house like a boat. If you have a dozen small little holes the water’s going to add up and your boat’s going to sink.

Similarly, your home might have proper insulation or ventilation installed, but small little pockets of air are going to leak out all that cold or warm air your HVAC system is producing. This means lost energy efficiency and higher energy bills.

Research shows that air leaks in your home can add up to one-third of your home’s total energy loss throughout the year. By air sealing your home, you’ll be saving a tremendous amount of money, especially if you combine that with other insulation measures. For more information on cost savings, check out our guide: Is Air Sealing the Attic Worth It?

Whether it’s your attic, windows, electrical outlets, fireplaces, or floor holes, proper air sealing is going to help you reduce your energy costs a considerable amount.

Caulk vs. Sealants

Caulk and sealants are terms often used interchangeably. While they share some similarities, there are a few differences between these two products that we should address to reduce any confusion.

Caulk describes waterproof material that fills and seals joints between building materials. They’re typically made out of flexible polymers like latex or rubber.

Caulk can expand with temperature changes and absorb vibrations. Caulk can’t crack, which is why it’s often used to connect materials on two different planes.

When compared to sealants, the biggest difference is elasticity. When dry, caulk is a lot more rigid than sealants, which are more suited for filling in spaces that are prone to expansion or contraction.

When you’re choosing between the two, consider the amount of stress that exists in the sealed area.

How to Seal Air Leaks With Caulk

Are you interested in air-sealing your home with caulk? Great!

Air sealing is a relatively inexpensive and easy DIY project that you can get done in a short time so long as you have the right equipment and know the right steps. Let’s go over some of that here.

Before You Start…

Make sure you have everything you need to get this project done. Here’s a basic shopping list for a successful air sealing project:

  • Caulk
  • Caulk gun if the caulk you purchase doesn’t come with a nozzle
  • Putty knife or large screwdriver to remove old caulk
  • Paper towels and rags for cleanup

Step-By-Step on Air Sealing

Start by removing any old caulk in the area you’re looking to seal using your knife or screwdriver. Make sure it’s nice and dry so you don’t caulk in any moisture.

If you’re using a caulking gun, cut the tip of the cartridge of the caulk at a 45-degree angle and insert the tube in the gun. Take some time to do a “test caulking” on a newspaper or paper towel. This will give you a good sense of what to expect so you don’t over-caulk a window or floor.

Hold the caulk gun or your caulk nozzle at a 45-degree angle against the surface you’re trying to seal. Using a “pulling” motion, keep the angle as you slide the tube along the open joint while pulling the trigger. Try to keep a consistent stream as you go along.

Once you’ve made a nice line of caulk or filled a single spot, use your finger or a spoon/paintbrush to dampen the caulk into the filling. This will force it deeper into the spot and help it expand.

Clean up any excess caulk with a rag, and let it sit undisturbed for about a day. How long the drying process takes will depend on the product you use as well as the humidity and air temperature.


Air sealing has clear benefits and choosing the right caulk is one of the most important steps to taking advantage of them. Use this article to find the right air sealing caulk and make your home more energy-efficient today!