What is Acoustic Sealant/Caulk and How Does It Work?

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There are many ways to deal with noise through cracks on walls. Some people use weather stripping or caulking, while others use special acoustic sealants. Still others use mass loaded vinyl, which is a heavy duty material that can be used to block out noise.

Using acoustic sealant will help dampen noise and vibrations. It can be applied around doors and windows to help create a barrier against sound.

It is also effective in sealing gaps and cracks that might allow noise to enter your home. Acoustic sealant is available at most hardware stores and home improvement centers.

In this guide, we shall be examining several acoustic sealant products available on the market and the complements.

What Is Acoustic Sealant

Acoustic sealant is an important part of any soundproofing project. It is used to fill in gaps and cracks that could allow noise to enter or escape from a room. It is available in both liquid and foam form, and can be applied with a caulking gun or spray can.

Most acoustic sealants are non-toxic, water-based, non-flammable, and freeze-thaw stable.

  • Acoustic caulk is most commonly used in conjunction with other soundproofing materials, such as acoustic foam or fiberglass insulation.
  • It is important to apply the caulk properly in order to achieve the best results. First, the area to be caulked should be clean and dry.
  • Next, the caulk should be applied evenly to the surface, using a putty knife or similar tool. The caulk should then be smoothed with a damp cloth before it dries.
  • Once the caulk is dry, it will create an effective barrier against sound.a woman applying acoustic caulk on gypsum wall

Acoustic Caulk vs Regular Caulk

There are two main types of sealants commonly used in construction and home improvement: acoustic caulk and regular caulk. So, what is the difference between these two types of sealants?
 

Acoustic Caulk

Regular Caulk

Acoustic caulk is specifically designed to block sound. It is often used in areas where noise transmission is a concern, such as between walls or in rooms with hard floors.

Regular caulk, on the other hand, is designed for sealing cracks and gaps. It can be used in a variety of applications, such as around windows and doors, in bathrooms and kitchens, and more.

Acoustic caulk is typically made of a thicker, denser material than regular caulk, which helps to block sound waves.

Regular caulk is typically made of a thinner, less dense material than acoustic caulk, which makes it easier to apply and spread.

What Makes a Sealant an Acoustic Sealant?

Regular sealants with time dry and crack, unlike acoustical bonds that permanently remain flexible, don’t shrink or expand.

A regular sealant only blocks airflow but allows sound waves transmissions in the form of vibrations.

On the other hand, acoustical caulks convert sound waves into negligible amounts of heat.

Top 7 Acoustic Sealants

Now that you’re familiar with what sound dampening sealants are and how they work let’s look at some of the most recommended ones. Some of these products adhere to construction materials and a variety of automotive sound-deadening materials.

1. Green Glue Acoustic Sealant

Green glue acoustic sealant is a noise-proofing sealant used to fill joints and gaps where the wall meets the ceiling or the floor and where two walls meet.

It can also be used around switch boxes and other outlet boxes.

It’s an easy-to-install product that can be easily be painted using soundproofing paint, ideally after 48 hours.

Green Glue Noiseproofing Sealant improves the Sound Transmission Class (STC) rating, which is obligatory in LEED-certified structures.

Read my guide on determining the STC ratings of a wall all by yourself.

The best part is that the product is non-hazardous, doesn’t have odors, resists drying and cracking, and stays permanently flexible.

It helps block low, medium, and some high-frequency noise. However, it’s not for use in exterior walls, around water pipes, or plumbing installations.

You should clean up easily with soap and water before it cures.  

The sealant is available either in singles or sets.

2. Quietzone Acoustic Sealant

This product is designed to absorb sound vibrations within the walls cavity to control noise in your house.

It works by stopping sounds from traveling through small openings and cracks on ceilings and floors.

Manufactured by Owens Corning, this product provides an effective method to reduce noise transmission between rooms.

It also significantly reduces the noise coming around windows and exterior doors.

Because it can be used on exterior doors, this product makes a great alternative to green glue.

However, there are precautions one should take with Quiet Zone sealant.a man applying fireseal acoustic sealant on the wall

It may cause eyes and skin irritations and is harmful when inhaled or swallowed.

You should avoid vapors or breathing and use it with adequate ventilation.

3. Liquid Nails Acoustical Sound Sealant

LIQUID NAILS Acoustical Sound Sealant is a flexible latex sealant designed to decrease sound transmission in any type of wall system.

The product passes ASTM E 90 for impressive acoustical properties.

It has also been tested as per ASTM E 84 for smoke generation and flame spread.

Just like green glue sealant, you can use liquid nails to seal around openings, and seams including electrical boxes, cutouts, perimeter joints, as well as soundproof windows, and any other areas where air may leak through.

4. OSI SC175 Draft and Acoustical Sound Sealant

This product helps damp sound transfer through walls, floors, and ceilings.

Additionally, it can be applied around panel and wall perimeters for air vent noise reduction and electrical and lighting cutouts.

Not only does it block sounds, but it also acts as a draft stopper.

It’s non-flammable, latex-based, whose primary function is to achieve and maintain improved STC ratings of the system designed.

The sealant is paintable and remains permanently flexible.

It adheres to metal studs, such as resilient channels, gypsum boards, concrete, and most building materials.

Uncured adhesive residue can be removed with just soap and warm water, while cured requires a sharp-edged tool to cut away.

5. Auralex Acoustics STOPGAP Acoustical Sealant

The StopGap sealant is a water-based elastic sealant used for reducing noise transmission around electrical box cutouts or at the perimeter of wall systems to achieve improved STC/MTC values.

The surface dries to form a tough film; however, the sealant remains flexible and also flexible for up to five times than competitor brands.

It has no residual run-off, it’s paintable, non-staining, and meets all ASTM E-84 standards for fire retardant.

The product comes in a large 28 oz container and requires a larger than normal caulking gun that can be purchased online.

Acoustic Sealant Application: What’s Required?

Acoustic sealant application is determined by the magnitude of your soundproofing project.

It can be used alongside other sound-deadening materials to improve soundproofing efficiency and achieve higher STC ratings for walls.

Before application, make sure that the surface is clean, free of dust, dirt, and moisture.

You should use a knife or scissors to clean cracks and holes on the ceiling to ensure that they are free of dust.

Holes that are too small may not create an effective seal because it’s hard to fill with the paste.

Holes should be around ¼ to 3/8″ for the best application.

Apply the sealant to the hole or crack and wipe off the excess with a paper towel or a piece of cloth within 30 mins after application.

However, for cracks larger than 1/2″, you need a backer rod for filling with caulk.

Larger openings around electrical boxes, doors, and windows require multiple layers for a complete seal.

You should allow the sealant to cure before painting or installing an acoustic soundproofing wallpaper to improve noise reduction.

 

Acoustical Sealant Vs. Silicone

Acoustical sealant and silicone are two materials commonly used for sealing cracks and gaps in buildings. They are both effective at sealing out noise, but there are some key differences between the two materials.

Acoustical sealant is a bit more expensive than silicone, but it is also much more effective at blocking out noise. It is also easier to apply and can be painted over if desired. a handyman comparing silicone and acoustic sealant

Silicone is less expensive but not as effective at blocking out noise. It can be difficult to apply evenly and can be messy to work with.

Silicone will permanently dry while acoustic sealant will remain flexible. This means that silicone is more likely to cracking over time while acoustic sealant will continue to provide a seal.

Final thoughts

Acoustical caulking plays a vital role in blocking flanking noises transmitted through structures.

They retain flexibility and don’t dry hence aiding in both sound and draft blocking.

While there are various products on the market, my top recommendation is the Green Glue Noiseproofing Sealant.

The best part is that it meets all the criteria you’d wish for in a noise-controlling sealant.

Regardless of how sound travels, this product will get you sorted.

However, it’s always important to note that a sealant alone won’t make a room soundproof.

You should instead combine it with other soundproofing products.

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