Best Acoustic Caulk and Sealants for Soundproofing [2024]

Soundproofing a room can be very hard to achieve even if you use the best soundproofing material but forgot to seal up cracks and gaps in spaces. Sound waves can pass through the tiniest of cracks and disturb your peace. 

To ensure that you are getting the best soundproofing properties possible use the best soundproofing material in conjunction with the best acoustic caulk and sealants for soundproofing. 

Acoustic caulk not only blocks sound transmissions but also blocks upward and downward drafts coming in from cracks and gaps around windows

All you need to know about best caulking for soundproofing can be found below, including some Green Glue alternatives). Everything from what it is all about to how and where you should use it is all detailed. So without further ado let’s first look at the best acoustic caulk you can find. 

Acoustic Caulk



Best acoustic caulking for soundproofing


Probably the best and the most expensive on the market, Green Glue is a high-quality sealant used to fill cracks, gaps, and seams 1/8” to 1/4″. It works great around electrical boxes, doors, and windows to block sound waves and vibrations.  Use it to seal around HVAC openings, and even along metal ducts to minimize noise.

Green Glue remains pliable when cured so it renders it a good option for acoustical use. It blocks low frequency plus mid and upper range noises. The glue dries down to a white color in 48 hours and can be painted in any color of your choice.

It is non-toxic, has a low odor, and both mold and mildew resistant. The sealant can be taped or mudded over and is not suited for exterior use or around pipes or plumbing. It comes single or in sets of 6 29oz tubes.

Application is easy with even easier clean up in the event you spill some. It is advisable to clean it up before it cures with soap and water. However, if you couldn’t and the glue cures, peel it off with your fingers and clump it into a ball and discard properly.


Franklin Sound Sealant seals openings and remains flexible to prevent sound leakage where noises can filter in. It can reduce vibrations and eliminate mid to high-frequency transmissions through walls.

This sealant increases STC values and upgrades the sound quality. It is VOC compliant, non-flammable, fire-rated, and environmentally friendly for use just about anywhere. Do not use hot pipes or ducts since it isn’t heat rated.

The Franklin Sound Sealant takes over 48 hours to cure and can be painted once it does. Just make sure you leave it long enough to cure fully before you attempt to paint it. You can get this sealant in single tubes of 29oz. Clean up is easy and done with just water.

Auralex STOPGAP is for use in cracks and gaps around your windows, walls, floors, ceiling, and doors. It is a highly elastic, water-based sealant that is waterproof, flame retardant, and non-staining. STOPGAP has no residual runoff and can be painted as well.

When applied according to ASTM C-919 applications, it can achieve an STC rating of 53. To do so, it is best to place two beads of sealant at the top, bottom, and around all of the perimeter edges.

The STOPGAP comes in 28 oz tubes and can approximately cover 40 linear ft. with a 3/8 inch bead applied. It can be cleaned with just water in case you spill.


Everkem Sound Seal is a powerhouse of a sealant and adheres to drywall, wood, metal, and concrete. This sealant is a non-flammable, latex-based sealing compound that reduces sound transmission from room to room.

In addition to its sound sealing properties, the Sound Seal 90  serves a draft stopper and smoke sealant. This prevents the passage of air, smoke, fumes, and toxic gases. This white acrylic polymer sealant remains permanently flexible and resists drying, cracking, or splitting.

Depending on various factors such as humidity and temperature, this sealant takes anywhere from 3 to 7 days to cure. Clean excess with a cloth, paper towel, or acetone when wet. If the excess dried, the scrape or cut the excess off.

In a test, it showed that Sound Seal used in a construction assembly improved an STC of 39 to an STC of 52. You can get this sealant in 28 oz plastic or fiber tubes.


Sashco Big Stretch Caulk stretches to more than 500% of its original size. With that great level of stretchability, Sashco caulk always sticks and never cracks.

Big Stretch twist, bends, compress, and stretch to handle the seasonal expansion and contraction of materials.

It adheres very well which is exactly what you want in an acoustic sealant. It is effortless to use and apply due to the 10.5 ounces or 29-ounce cans with efficient nozzle applicators.

You can use it on various building materials, around vinyl siding or windows, and even seal gaps around crown moldings. It is a low odor and cleans up easily with just water.

acoustic sealant blocks out sound better when used in home theaters

What is acoustical sealant caulk?

Acoustical sealant caulk is a special type of soundproofing caulk. It is primarily designed to absorb sounds that aid in soundproofing. It is a water-based, non-flammable, and flexible sealant that adheres to most building materials.

Sounds create energy that travels via waves and vibrations. Sound waves and vibrations travel through the air and reflect off any hard surfaces. They are more powerful at their source and weaken as they travel. 

Sounds can be transmitted through the tiniest of cracks and creases and this where you use acoustic sealants. They act as a barrier and absorb the sound waves and vibrations so the noise is reduced greatly in the room.

They are used in addition to other sound-blocking materials and work by filling in gaps and cracks. Some of the other soundproofing materials may not be applicable to apply to certain spaces, hence, where the acoustic sealant comes in. Sounds can pass through anywhere that air can so not filling cracks and gaps will hinder your soundproofing attempts. 

The rubbery sealant, made from silicone material offers a permanent solution to filling these spaces since it does not dry out, crack or shrink over time. It remains pliable at all times and can handle the seasonal expansion and contraction of materials.

Acoustic caulk vs regular caulk

Let us dive a little deeper and look at the advantages of acoustic caulk vs regular caulk.

Acoustical caulk differs from regular caulk when used for soundproofing. Acoustic caulk is better used for soundproofing while the regular caulk is best suited for sealing around pipes to prevent water damage. Regular caulk is most likely to be used in bathrooms and wet areas. 

Regular caulk dries and hardens which causes the caulk to shrink or crack after a while. When the caulk cracks it can no longer stop air movement thereby allowing sound waves to pass through. Although regular caulk stops some sound waves when applied at first, it does not stop sound vibrations and can actually amplify it. It provides what is called a reflective surface where sound waves bounce off of.

Acoustic caulk on the other hand absorbs sound waves and sound vibrations due to its flexible nature. It provides a more permanent solution as it remains pliable at all times so no cracking of the sealant happens.

Another major difference is that acoustic caulk adheres to almost any building material surface and keeps it tightly connected for years without losing its suppleness as it dries down. Regular caulk only works with specific types of materials.

Now you may come across some products marketing themselves as an acoustic sealant or acoustic compounds. So what’s the difference?

The main difference between the two is the formula. The acoustic compound is used to minimize sound transfer. It converts soundwaves into heat energy to dampen sound. The compound is usually a viscoelastic material suitable for applying between drywall and other soundproofing materials. Keep in mind that the compound used may take up to 30 days to cure fully.

Sealants come in tubes and cures in 48 hours. These prevent penetration by sound, air, or moisture by providing an acoustic barrier. The Compound and Sealant though different and used for different purposes can provide a high level of soundproofing ability. If they are used for their intended purposes in a single room, it will increase the STC value of that room.

In brief, the main advantages of using acoustic caulk over regular caulk are:

  • Absorbs sound waves and sound vibrations thus reducing sound transmission
  • Remains supple and won’t harden, crack or shrink.
  • Adheres to almost any building materials
acoustic caulk vs regular caulk and use

Things to consider before buying soundproofing caulk

Selecting the correct soundproofing caulk can be a challenge if you are fairly new to the whole idea. 

To ensure you are getting the best product for the job, keep these few things in mind before you purchase. 

The base of the soundproofing caulk

Carefully read the description of the product before you buy it. 

Some soundproofing caulk does not work well with wood while others may not work with corrosive metals. 

This is a crucial step because you do not want to end up with a product that does not work with your building material. You will not be able to achieve any soundproofing properties and it may damage your building material as well.

Water-based solvents are easier to work with and clean up easily. They are usually non-toxic, low odor, and VOC compliant. They are best suited for use on porous materials. Solvent-based options work best in dense materials such as marble and porcelain.

Waterproofing Ability

This is extremely important if you are looking for a soundproofing caulk for exterior use. Only a waterproof sealant will be able to withstand hard weather conditions and work in the way you want it to. If you choose a soundproofing caulk that isn’t waterproof, you will find yourself having to redo work regularly on the exterior of the building to block sounds. 


In today’s world, we are all trying to save a buck or two. Choose acoustical sealants that have rave reviews from actual users. A key point to note is that expensive doesn’t always mean better. However, some of the more expensive ones are of better quality. If your budget permits, then by all means go ahead. 

Finishing Product

Check to see if your soundproofing caulk can be covered up if you are using it in invisible spaces. You may want to paint it or use some other material to cover it so that it blends in with your decor. 

How to use acoustic sealant

Acoustic sealants are used to fill any cracks, gaps, and crevices to fully soundproof a room. This can be just about anywhere in or outside the home where you want to stop sounds from filtering in. 

The can be used in areas such as:

  • Joint between drywalls.
  • Joints in the Ceiling 
  • Joints in the Flooring
  • Around doors and windows
  • Around the electric switch box frames

Those are just a few places as there are many more places where an acoustic sealant can be used. 

So how do you go about applying it? Stick with me as I lay it out step by step.

1. Clean surfaces

Before you even attempt to apply the acoustic sealant, clean the surfaces where it’s going to be placed. Ensure all surfaces are free from dirt, dust, or moisture. Use a utility knife to clean the crack or gap if you can remove any remnants of other materials for the best results.

2. Cutting the nozzle.

Acoustic sealants usually come in tubes with sealed nozzles. You will have to cut an appropriately sized hole for your desired bead diameter. Most times a 1/4″ to 3/8” opening is best but may not always be the case. Cut bigger holes for higher surfaces or smaller for more narrow ones.

3. Application

Apply the acoustic sealant to the gap or crack and smear it with a tool. Since the sealant cannot be easily squeezed from the tube, you will need a caulking gun to assist or choose a sealant that comes with an applicator.  After application, be sure to wipe away any excess or mess with a cloth, paper towel, or tool. Do so within 15 to 30 minutes after you apply it before it starts to skin over. 

You can apply it in either of these ways

  1. Apply one layer on both sides
  2. Apply an extra bead under the one layer of sealant on both sides for a better seal.
  3. Add multiple layers of sealant with beads under each layer and a heavy bead under the plate for an excellent seal.

4. Leave it to dry

Acoustic sealant takes about 48 hours to dry so do not interfere with the area at all during this period. While some sealants can be painted or covered with other materials, wait until the 48 hours are up before doing so.

5. Apply finishing product

Check to see that the sealant has dried fully before you apply a finishing product of any kind. Most of these are safe to be applied directly to the acoustic sealant.

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