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!