Air Sealing for a Healthier Home

Air Sealing for a Healthier Home

Do you often experience headaches, allergies, fatigue, or physical discomfort in your home? 

If you have a lot of health issues, your home may have something to do with it. A home with even tiny cracks, gaps, and holes can lead to drafts, allergens, rodents, bugs, and mold, which can all contribute to poor health.

So, what can you do about it? The answer might surprise you. Air sealing is a small project that can make a big difference in your home’s health and comfort, as well as reduce energy waste. And the good news is, you can easily air seal with just some caulk, spray foam, and weatherstripping. 


You’ve heard of avoiding drafts so you don’t catch a cold, right? Although there isn’t any solid evidence that drafts alone make you sick, it’s likely that drafts are associated with illnesses because they are also associated with cold weather. And rhinoviruses, like the common cold or flu, travel on air and best survive in colder temperatures.

So, when you air seal gaps and cracks that cause those drafts, it isn’t for the draft alone—although it will make your home more comfortable. It’s also to keep out the cold air that airborne illnesses love to travel on.


Have you ever seen the huge plumes of pollen that come from trees? There are plenty of videos out there to show this remarkable yellow dust storm, but here’s a great example

All that pollen floats on the wind and travels through the air. In fact, in the spring, if you keep your windows open, you might even see a light coating of dust on your surfaces, like countertops and tables. 

So, just keep your windows closed, right?

While that might stop some of it, pollen particles are super tiny and can find their way into your home through small cracks and gaps. And if you have allergies, you won’t be able to escape them by avoiding the outdoors.  

Pollen isn’t the only notable outdoor allergen that makes its way inside. Dust, mold spores, and pollution from traffic or industry can all make their way into an unsealed home. And they can initiate allergy symptoms, irritate sinuses, and cause a range of respiratory issues. 

Luckily, caulking around windows or weatherstripping doors can help seal up your home and ultimately improve the quality of your indoor air for better health.

Rodents and Bugs

Rodents and bugs, like cockroaches and flies, can carry a range of diseases and bacteria. Think salmonella, staphylococcus, streptococcus, E. Coli, and listeria. (Yuck!) Bugs and rats scavenge anything from crumbs to spilled food and even fecal matter (double yuck…). Plus, they crawl and climb with seemingly no limitations. They can transfer bacteria through their droppings, which can end up on food or in food preparation areas, like kitchen counters, plates, cutlery, and cutting boards. 

Although keeping your home clean is important, sometimes it isn’t enough to keep the bugs and rodents out—they’ll often find their way in when the indoor environment is preferable to the outdoors, due to moisture or temperature. And who can blame them?

That’s why we recommend air sealing gaps and holes so bugs, spiders, and even rodents can’t find their way inside.

Check out this video to see how easy it is!

Indoor Mold

If your home isn’t air sealed well, there is a great chance that humidity is building in certain places, causing chronic moisture that can lead to mold. 

That’s because the difference in air pressure between the inside of your home and outside causes air you don’t want (for instance, moist, unfiltered outdoor air) to move into your home through gaps and cracks. And where warm air meets cold air (which is common near gaps and unsealed spaces), moisture droplets can form. These cling to areas around gaps and holes and struggle to dry out, creating the ideal environment for mold and mildew to grow.

And that’s not ideal for you. Because this mold can cause major respiratory and health issues, such as sneezing, watery or gunky eyes, coughing and wheezing, headaches, fatigue, and bronchial issues. 

If you’re experiencing any of these types of symptoms, pay attention to mildew and mold smells, and try to find where they are coming from. Look around your home for cracks, gaps, and holes and air seal them. Air sealing might not be what the doctor prescribes, but it’s a commonly overlooked step toward better health and well-being. 

How to Air Seal Your Home Without the Mess

So, you’ve decided to air seal your home. That’s fantastic! You’re well on your way to reducing energy waste, eliminating drafts, keeping out pesky pests, and making your home healthier. All by just barely squeezing a finger (and we mean that literally).

Air leaks from tiny cracks and gaps in your home can add up to the equivalent of a two-square-foot hole, which is like leaving a window wide open in your home! Time to air seal, right?

Except, now you might be wondering: “How do I air seal without making a big ol’ mess?” 

You may have seen smears of caulk on window frames, large clumps of spray foam sticking out from gaps around old openings, or bulging caulk lines and drips and strings from poorly applied caulk. And you’re probably thinking you don’t want those unsightly air sealing messes around your home.

And we don’t blame you!

But here’s the thing — whoever applied that caulk or spray foam didn’t read this article. Because we’re going to share the top three tips that can help you avoid the most common air sealing messes. Air sealing is actually very easy, if you know what you’re doing, and we’re here to make sure you know what you’re doing. 

How Can I Make Expanding Foam Less Messy? 

Expanding foam, or spray foam, is the tool of choice when you find large gaps that need to be sealed. For instance, behind clothes washers, dryers, and where plumbing enters the home, you may find gaps that not only let air in and out but are also highways for bugs and critters. Expanding foam can put an end to that.

But here’s the thing with spray foam… it’s messy. It never leaves a smooth surface, and it’s kind of unpredictable. So how can we seal our homes without bubbling growths of foam everywhere? 

There is good news. Excess foam can be cut off easily. Use a razor blade, box cutter, or serrated knife to slice off any protruding foam. It still won’t look perfect and polished, but if the area is hidden (for instance, behind a dishwasher), you don’t have to worry much about aesthetics. You can even skip slicing the excess entirely, like in this helpful GIY video.  But, if the foam is exposed for everyone to see, you might want to neaten it up a bit more.

To do that, after slicing off the excess, you can sand it down until it’s smooth. We recommend a dust mask to avoid breathing in any dust. Or if the area is small enough and a bead (or line) of caulk could cover it, you can also add that on top of the foam, using your finger to smooth out the finish. This is best with cracks and lines but may be a bit messier with larger holes or gaps. 

You may also consider priming and painting the foam to match surrounding walls or surfaces. This is recommended if the foam will be exposed to sunlight.

Word of caution: Just because it’s a big gap doesn’t mean it’s a good place for expanding foam. Be sure it is not trapping heat in a small area, as this can be a fire hazard. Avoid breaker panels and recessed lighting fixtures.

Why Are My Caulk Lines So Messy?

Expanding foam isn’t the only mess-making air sealant. Have you tried to use a tube of caulk by itself without a caulk gun? Then you know all about zigzagging caulk lines, random bulges, and unruly caulk ending up in all sorts of places.

Who can work like that?

To avoid this type of caulky mess, skip the hand-squeezed tube, and get yourself a caulk gun and corresponding caulk tube. You’ll marvel at the wonder of a caulk gun as you effortlessly apply pressure to the bottom of the tube with the gentle squeeze of a trigger. Simply align the tip, gently press the trigger, and move the gun at a consistent pace (like putting toothpaste on a toothbrush!). You’ll get a consistent bead width all the way along the crack. 

Why Do I Have So Much Excess Caulk?

For new air sealing DIY-ers, excess caulk can be a problem. Usually, the cause is simple: The applicator hole size is too large. If you’ve cut too much of the tip off the applicator, it will discharge too much caulk at once, making the process messy and hard to clean up, even if you’re using a caulk gun.

To avoid this, start by cutting just the end of the tip of the caulk applicator, which will produce a small hole. Caulk your smallest cracks first. If you find it isn’t enough caulk for the larger cracks, then you can always cut off more of the applicator for a bigger hole and wider bead.  

Check out this video by This Old House and see how a small hole, a caulk gun, and a “handy” technique can do some beautiful work. (There are also caulk finishing tools made specifically for tidy application.) 

Air sealing may feel intimidating when you haven’t done it and don’t know what to expect. But hopefully, knowing just a couple tips can increase your confidence and encourage you to give it a try! These quick tips will make it go (and look!) a lot smoother. 

Yes, your home has bigger projects that you might need a contractor for, but this isn’t one of them. Keep that hiring-a-pro money in your pocket by tackling air sealing yourself. 

So go on! Seal it!

Home Winterizing Checklist

Pumpkin spice lattes. Vibrant, fiery leaves. Candy corn and bite-sized candy bars…fall has arrived and winter is on its way! Which means it’s time to start thinking about winterizing your home.

What is winterizing? It’s exactly what it sounds like: prepping your home for the colder weather. 

“But wait,” you say, “Isn’t winterizing just for people who have cabins and lake houses?” Actually, no. To avoid wasting energy and money from air leakage, every home should be winterized. 

Air leaks from tiny cracks and gaps in your home can add up to a two-square-foot hole in your home. It’s basically like having a window open 24/7!

In addition to reducing energy waste, you can also avoid those annoying drafts and pesky insects and bugs that rush into your home as the weather gets cooler—air sealing can keep them out.

In a few quick steps, you can make your home healthier, cozier, and more efficient during the cold season. So, before you dust off your boots, sweaters, and scarves, let’s winterize!

Change air filters and clean vents

If you haven’t run your heating system in a while, it’s a good idea to check your ducts, clean your air filters, and vacuum or sweep out openings. This ensures you aren’t blowing extra dust and allergens around that can wreak havoc on your immune system during cold season.

Clean your gutters and roof

Gutters tend to fill up in the fall with leaves and debris. You should always keep your gutters clean because packed gutters can lead to water damage. In the winter, ice blocks can damage your gutters, siding, shingles, and roof. So be sure to clean them out before the cold weather comes. Consider leaf guards for your gutters, too, to prevent a buildup of debris.

Clean your chimney

If you haven’t used your chimney in a while, it’s a good idea to check and make sure no one else has! On top of looking for critters and their homes, look for soot and cracks and any anomalies. Call a chimney pro if something looks off.

Reverse the direction of your fans

Most fans have a switch to reverse the direction of airflow. Because warm air rises, this can be helpful in the winter to push warm air back down.

Look for light coming in between the door and frame

Do you see little slivers of light around your door? Then you should get some weatherstripping! This is a common air leak space that can exchange air quickly, making it hard to keep your home heated. There are several types of weatherstripping for doors. Check out this video from This Old House for a quick introduction.

Check all your windows. Do you feel a draft when they are closed?

If you feel cold drafts around your windows, even when they are fully closed, there are many options for tightening them up. A simple step is to be sure you lock your windows, which tightens up the space between top and bottom sashes and the frame. You also might need to caulk around the window frame or use weatherstripping to ensure they seal well. Watch this video from This Old House for ideas on how to make your windows more energy efficient and keep in the heat during the colder months. 

Change out your curtains

If you have been using light, airy curtains during the warmer weather, consider switching them out for heavier ones. This can help trap heat indoors, meaning less heat is transferred through your window glass.

Speaking of windows again… do you have storm windows?

Windows lose far more heat than walls, so they’re an important piece of ensuring your home stays warm during cooler months. Another recommendation to keep heat in and avoid wasting energy is removing screens (if you have them) and replacing them with storm windows. The double panes trap air, which acts as a layer of insulation, keeping heat in and cold air out.

Check behind appliances

When was the last time you moved your dishwasher, range, or dryer and peeked at what’s behind? If it’s been a while, don’t worry—that’s common. But here’s why you should change that: This often-overlooked space can contribute to drafts and heat loss and even bugs and critters. That’s because there are often unsealed gaps in these spaces where plumbing and more go through the walls. Expanding foam is a great tool to seal up larger gaps and ensure that air, bugs, and critters can’t get in during the winter months. 

There are many simple things you can do to prepare your home for winter. Start with this checklist, and you’ll be on your way to a cozy, comfortable winter. To learn a little more about where air might be coming in during the winter months, and how to fix it, check out this video from This Old House

And then go winterize, save some energy, and create a happy, healthy and cozy home!