Soundproofing spray foam for existing walls

This blog looks at how spray foam can be used in existing walls. I’ll also go over some of the main advantages of installing soundproofing spray foam insulation in the home.

Spray foam is a popular construction material that is used in home construction for wall thermal insulation. It’s available at most hardware and construction supply stores, as well as home improvement and maintenance retailers. This spray foam’s main goal is to make your home warmer in the winter and cooler in the summer. However, because it creates an additional sound barrier between connected walls, it is also utilised to control noise.

The thicker walling is more durable and makes sound waves more difficult to penetrate. Acoustic spray foam is the name given to this product when it is employed as a soundproofing medium. It aids in sound absorption and noise reduction in your home’s interiors.

Many householders and renovators choose this material to sound-deadening wall panels or sound-deadening paint.

Polyurethane is used to make this spray foam, which can be closed or open-celled. Polymeric MDI and a combination of polyol resins, as well as fire retardants, surfactants, and different catalysts, are among the ingredients. Surfactants serve as blending agents and emulsifiers, while fire retardants help to prevent combustion and smoke.

Other solutions for efficient noise reduction in your house may be recommended by sound control professionals. When soundproofing spray foam is used to plug gaps and cracks in walls and around window panes, however, some exterior noise can be blocked from entering your rooms.

How to Use Noise Control Spray Foam on Existing Walls?

Three economical and successful ways to utilise sound control spray foam on existing walls are as follows:

  • Sealing Wall Cracks and Crevices
  • Apply Spray Foam between Drywall
  • Use Foam Spray around Acoustic Panels

How Does Spray Foam Work?

Spray foam is easy to work with and may be used in a variety of situations. It is simple to apply to the undersides of roofs and existing walls by drilling small holes and inserting the foam inside. It’s not only wonderful for soundproofing, but it’s also a good insulator, keeping your home warmer and saving you money on your energy bills by up to 50%.

What Are the Benefits of Spray Foam Soundproofing?

Easy Installation

The ease of installation is among the most significant advantages of spray foam. You may spray foam on any existing surface in your home given the nature of the spray foam and the size of the nozzle used to apply it. Soundproofing spray foam insulation can be installed without tearing down walls or lofts. The foam instantly expands after being sprayed to fill any gaps or fissures on the surface.

Excellent Soundproofing

In your house, soundproofing spray foam insulation can provide exceptional soundproofing benefits. Soundproofing has numerous advantages, including improved privacy. You may rest assured that your private and sensitive information and chats will not be overheard by outsiders. It also helps you to live your life without being bothered by outside noises. You can watch late-night films or sports in the privacy of your room.

Lower Energy Costs

Spray foam sound insulation has the added advantage of blocking air leaks. Spray foam can expand multiple times, resulting in excellent air sealing. It can seal gaps and holes through which mice, bugs, and other unwanted visitors can access your property. Spray foam insulation will also result in a more consistent temperature in your home. 

As a result, your house will be more relaxing in the summer and warmer in the winter. This will cut down on the use of air conditioning and heating, which will help you save money on your energy bills. Because heat escapes from your home, your air conditioning and heating systems don’t have to work as hard, increasing their efficiency and lowering your energy bills.

Improved health and life quality

Spray foam insulation for soundproofing is made entirely of water, making it completely eco-friendly for your family and home. It aids in the reduction of airborne contaminants within your house. As a result of the significant reduction in airborne contaminants in your house, respiratory distress is eliminated. Spray foam roof insulation contributes to a better quality of life and health.

Spray Foam Insulation’s Drawbacks 

  • Spray foam insulation connects wall components, enhancing sound vibration transfer
  • Sound absorption is limited or non-existent
  • Reflective resonance, feedback, and sound distortion have all increased
  • Messy and potentially harmful to one’s health
  • Expensive

Which Is Better for Soundproofing: Open Cell or Closed Cell Foam?

A porous matrix of interconnecting open cells is known as open-cell foam. It has a lower rigidity than closed-cell foam and enables some air and moisture to pass through. Because the open structure traps sound better than closed-cell spray foam, it is more effective at noise reduction. Hard surfaces, on the other hand, do not absorb sound waves; instead, they block, reflect, bounce, or resonate more.

The cells or bubbles in closed-cell foam close up and harden into a more robust and hard mass. Thermal voids are provided by the air in the cells, and the closed structure inhibits moisture and airflow infiltration. Some sound waves are blocked or reflected by the hard surface, while others, regrettably, resonate through it.

Sealing Wall Cracks and Crevices

Around half of all noise can get through your walls through gaps and crevices. You can have a more tranquil home life if you use excellent spray foam to seal all of these weak points and gaps. You can add extra soundproofing materials when the foam swells, fills all the cracks and dries. Acoustic foam panels, wallpaper, and soundproofing paint are some of the examples of these materials.

To increase the solubility of interior room noise, utilise acoustic foam panels in conjunction with soundproofing foam. You can improve the quality of your home’s rooms for reading, studying, chatting, and sleeping by reducing both interior and outdoor noises.

Materials Needed
spray foam
Acoustic foam panels
soundproofing paint

Apply Spray Foam between Drywall

You can lessen sound vibrations from exterior wall contact by spraying noise-controlling foam spray between the drywall. Sound waves are absorbed and reduced by the foam between the drywall, keeping your rooms calmer and much more pleasant. To ensure good filling and closing of weak places that allow outside sounds to enter your room interiors, utilise open-cell foam spray.

Foam spray can be messy and time-consuming for beginners to DIY home soundproofing approaches. However, with some patience, people will see how efficient and cost-effective it is as a soundproofing option for the home.

Materials Needed
open-cell foam spray

Use Foam Spray around Acoustic Panels

Spray foam along the margins of each panel while placing acoustic foam panels on a wall. It’s a good idea to spray around the entire collection of panels if you’re covering a significant part of the wall with these panels. This will help to seal any minor crevices, cracks, or gaps and will help to prevent or reduce sound transfer from the outside.

Before installing the acoustic panels, you can use foam spray to fill in any gaps or fractures. Before you apply the panels, you’ll have to wait for the foam to cure. When the job is finished, meanwhile, you will profit from more thorough soundproofing.

Effective soundproofing using spray foam

Vibrations and noise can easily pass through walls due to their hard surfaces. Effective soundproofing can be achieved when soft, malleable, and spongy-like substances like foam spray are added to them. Foam panels for noise dampening are made from soft, flexible, and absorbent polyurethane that reduces both original and echoing sounds.

We now understand that soundproofing spray foam alone will not provide the highest level of sound absorption. However, when combined with other successful sound-deadening techniques, it provides a solid foundation. The foam spray complements and improves the effectiveness of the other approaches for effective sound absorption and reduction.

Soundproofing spray foam insulation with polyurethane foam, for instance, can seal all gaps and crevices in a room’s walls. This improves the walling’s strength and stability. After that, you can apply up to three layers of sound-deadening paint to attenuate any external wall sounds. Multiple applications of this paint will effectively reduce sound wave transference from the outside due to its thickness.

After the paint has dried fully, you can reinforce the soundproofing with a succession of acoustic foam panels. Most panels should be placed on the wall sections that get the most sound impact and transmission. Even when outside noise levels rise, this clever combination of noise suppression techniques and materials can maintain your home’s interiors quiet.


Spray foam soundproofing for existing walls is not regarded as an ideal solution for completely blocking external sound. It is, nevertheless, quite effective in reducing noise levels caused by sound waves that enter your home’s walls. Foam spray, on the other hand, provides a great foundation to build on when used in conjunction with other noise dampening and soundproofing solutions.

This contemporary material is widely used as a wall sealer to close gaps, fractures, and fissures. It also creates a strong seal around the edges of acoustic foam panels to improve soundproofing. Soundproofing paint is frequently used in combination with this product. Spray foam’s employment as a valuable component of a soundproofing or noise reduction scheme is likely to continue for many years to come.

Frequently Asked Questions (FAQs): Soundproofing spray foam for existing walls

Should You Use Spray Foam Insulation or Injection Foam Insulation to Reduce Noise?

The ease of installation is a big benefit of employing foam insulation to deaden undesired outdoor sound in your home. It may be fitted without destroying or damaging your drywall in existing walls.

Both external and internal room walls can benefit from injection foam. 

When applied between the drywall, it can greatly reduce noise transfer from one room to another. If you have an attic, spray foam insulation is a wonderful alternative for reducing sound through a ceiling.

Is it possible to use foam spray to reduce noise in rooms with cathedral ceilings?

Spray foam insulation for soundproofing can also be used to reduce noise in a room with a cathedral ceiling. Your professional crew will begin by cutting panels into the ceiling. The foam is then sprayed into the ceiling cavities by the installer. The drywall is then rebuilt, and the seams are covered with a rough coat of drywall mud.

Is soundproofing spray foam effective?

Spray foam is an excellent choice for this application since both open and closed cell spray foam insulation work as sound barriers, preventing sound waves from travelling through the air and resulting in a quieter environment.

Is it Safe to Use Spray Foam in an Old House’s Walls?

Spray foam is not advised for minimising sound transmission through walls in an older home. It does not adhere well to older insulating materials, and as a result, it loses some of its efficiency. Additionally, when this foam is applied to the inner walls of older homes, excess moisture may be trapped between the drywall and the insulation.

Is it possible to apply sound insulation to existing walls?

Without breaking down your drywall, injection foam insulation can be put in your existing walls. Internal walls can also be injected foamed by drilling through the drywall to prevent noise transfer from room to room.

Is it possible to soundproof a wall with expanding foam?

Soundproofing spray foam insulation can be installed without tearing down walls or lofts. The foam instantly expands after being sprayed to fill any gaps or fissures on the surface. In your home, soundproofing spray foam insulation can provide exceptional soundproofing benefits.