Acoustic Caulk: Is It the Best Possible Soundproof Solution?

There are a lot of great reasons to soundproof the rooms you spend most of your time in. Maybe you’re looking for a less distracting workspace. Maybe you love your movie nights and don’t want to wake the rest of the family. Some basic soundproofing measures can cut noise considerably. Since proper soundproofing can be an expensive endeavor, cheaper options are always welcome. Acoustic caulk is one of those options.

You may be surprised at how far a simple bead of acoustic caulk can actually take you. In many cases, you’ll see a noticeable difference in excess noise. In some cases, it’s the only addition you need to fully isolate your space from the outside world. This high performance caulk is even specified by many architects to reduce sound transmission in new construction and remodels. 

With all these benefits, it’s worthwhile to look into this cheap and effective noise treatment. We’ll take a look at some basic soundproofing measures, as well as how acoustic caulk fits into the equation.

Soundproofing Basics

When it comes to soundproofing, there are two big things we’re after. Mass and density. Increasing mass and density reduces sound passage from one side to the next. In exterior walls, this may mean using some acoustic insulation inside, or mass loaded vinyl rolled onto the wall. They both add some mass and density, preventing a good deal of sound passage. 

When it comes to doors, we usually go for heavy doors with door seal kits. The heavier the door the better. If the door has a window, a double or triple-pane window with air or gas gaps between work best. Same thing with your exterior windows. More panes equal more soundproofing power. But adding mass and density to these places won’t necessarily solve all your problems.

Another thing that needs to be addressed in any of these spots is any gaps or cracks. Much of the sound leakage we experience in rooms is due to empty space in the facade. As a simple rule of thumb, if air can get through, so can sound. You’ve got to add some mass and density there too. You’ve got to fill those gaps and cracks with a quality soundproofing sealant.

How Acoustic Caulk Works

All caulks can seal cracks and gaps, but not all caulks are created equally. If you want to get the best soundproofing bang for your buck, you’ll need to use acoustic caulk. It’s different from the standard caulks you see at the hardware store. So, what makes acoustic caulk sealant  different from the other types we find at the local store?

Acoustic Caulk vs Regular Caulk

Most of the caulking we use around the house is silicone, acrylic, or some other material that hardens when dry. We often use these caulks around bathroom and kitchen fixtures, and even around windows and doors. They can work great for keeping air and water from getting through cracks, but aren’t great for soundproofing. Unlike traditional caulking, acoustical caulking is made of latex that remains flexible permanently, which is much better for soundproofing.

The reason caulk that stays flexible when hardened is better is that it doesn’t shrink or crack. Compare that with the way silicone shrinks and hardens when dry, and you can see why latex seals better. The better the seals we create, the better the soundproofing effects. Silicone caulk may block some sound at the beginning, but its performance will wane as it ages. In the acoustical caulk vs. silicone battle, the acoustical variety is a clear winner.

Most homes and offices are built with a lot of wood. Wood expands and contracts due to fluctuations in temperature and moisture. After a few years of hot summers and cold winters, you may notice a hardened caulk starting to crack. Once that old caulk starts shrinking and cracking, it won’t do you much good for blocking noise or heat. It’s time to replace it.

If you’ve got an older set of windows and doors, or the caulking has worn, replace it with acoustic caulking. It provides the same protection against air and moisture, but with added acoustical benefits. The fact that it won’t separate or crack also means it will look better for far longer.

How to Use Acoustic Caulk

The idea of using caulking for soundproofing may seem somewhat self explanatory, but you’ve got to know where to use it. It’s going to be more effective in some locations than it would in others. Let’s look at identifying where to put your acoustic caulk, as well as how to do it yourself.

Locate the Gaps or Cracks in Your Walls and Ceilings

You may look at your walls and say there are no cracks. If you don’t see large crevasses running up and down the walls, it’s a fair assumption. Unfortunately, you’ve probably got openings you can’t see. Your vents, electrical outlets, and small gaps around doors and windows all contribute to poor soundproofing.

That’s because these gaps and cracks present the possibility of flanking noise. What’s that? Flanking noise passes through gaps, cracks, vents, and other possible passageways into the next room. Loading those cavities with acoustic filler is the way to eliminate flanking noise from your rooms.

If you’re having trouble locating places where air can pass through, you can use a thermal camera. You can find cheap ones that work with your smartphone, and are pretty accurate. They will show you where cold or hot air is entering the room and where acoustic caulk will work well to soundoroof your wall.

Use a Quality Acoustic Caulk

Acoustic caulk will run you a little bit more than traditional caulks, but the difference is worth it. The price difference shouldn’t break your budget, and you’ll get better results. Use the best acoustic sealant you can afford to get the best results. Once you’ve decided on your caulk, it’s time to apply it.

soundproof caulk

Applying Acoustic Caulk

If you’ve ever applied caulk, you may already know how this is done. It’s a simple and straightforward process, and requires very few tools. There’s no reason you’d need to hire a professional to do it. That makes it an ideal DIY project. Here’s what you’ll need.

  • Tube or tubes of acoustic caulk
  • Utility knife
  • Standard caulking gun
  • Latex gloves
  • Caulk finishing tool (optional)
  • Towels or rags for cleanup
  • Painter’s tape
  • A little bit of free time

Prep the Surface

The first thing you’ll want to do is prep the surfaces where you’ll be applying the soundproof caulk. If it’s dirty or wet, you won’t get the seal you want. You’ll also want to be sure to completely remove any old caulk and residue that may be present. Wipe the joint down with rubbing alcohol, rinse with water, and allow to dry. Thoroughly cleaning and drying the surface is essential for proper curing. 

Tape Off the Area

If you want to get a clean line, you’ll also want to tape the area with painter’s tape. This will keep the caulk from ending up in places you don’t want it. Any excess caulk will easily pull off with the tape when you’re finished. Once you’ve prepped the surface, you’re ready to apply the caulk.

Ready the Caulk Tube

If the acoustic caulk came with a plastic cap and you won’t use the whole tube, cut above the line. Cut at a 45 degree angle. You’ll want to apply the caulk at a 45 degree angle, so matching that angle with your cut will help you get a smooth bead. The cut will also control the size of the bead. If you want a narrow bead, cut near the tip. If you want a thicker bead, cut a little farther down. Pull the plunger in the caulk gun all the way back and insert the tube. Push the plunger in until it makes contact, and you are ready to begin. 

Apply the Caulk

Start at one end and apply continuous pressure as you work the bead from one end to the other. Applying the bead in one direction will yield the best results. When using acoustic caulk for windows, you’ll want to make sure you go all the way around the frame. Any remaining gaps will allow sound passage. Fill any other cracks while you’ve got the tube open. If you have any remaining, you can cover it with the cap or insert a long wood screw.

Smooth the Bead for an Attractive Finish

Once you’ve finished applying your beads, finish it with a caulk finishing tool or your finger. Not only will this make the seal look better, but it will also make sure the caulk fills gaps completely. Allow it to dry, and your caulking for insulation will last for years to come.

Work with Pros to Identify the Best Solution

If you’re new to all this, it doesn’t hurt to consult the pros. We can show you where you’ll get the most benefit from acoustic caulk. We can also tell you whether or not you require a more robust solution. If you need something more substantial, we can provide you with the materials and expertise to get the best results.

Soundproofing the rooms where we spend the bulk of our time can deliver physical and mental health benefits. From reducing stress to increasing focus, creating more serene spaces comes with some serious upsides. When you’re ready to do something about unwanted noise, we’re ready to hear from you.


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