Can You Add Spray Foam Insulation to Existing Walls?
The Short Answer
Yes, it’s possible to add spray foam to existing walls.
The spray, in its liquid form, can be easily sprayed into a space, where it will expand, fill air pockets, and harden, creating an effective barrier from the elements. However, buildings with old insulation will make the process a little more difficult than those with none at all. This is because insulation that is moldy or damp will need to be thoroughly removed before applying spray foam in the existing wall.
Nonetheless, spray foam is still very much worth the effort because of the clear benefits. There’s energy savings (as insulation keeps your utility bills down), increased comfort (temperature is more easily regulated in an insulated home), and improved moisture control (as insulation clogs up pores that would let in moisture, limiting mold and musk from invading your space).
How Spray Foam Is Added to Existing Walls
Drill-and-Fill Method
This involves drilling small holes into the walls, injecting foam into them, and then patching them up to make the holes imperceptible. This work means you won’t even notice there weren’t holes there at all, plus you’ll get all the benefits of an insulated home or space.
Interior vs. Exterior Wall Access
Interior walls require the drill and fill method, but it is a misconception that exterior walls can’t also be worked on to receive spray foam insulation. This is indeed doable, and it doesn’t have to go through the atticyour existing walls can be insulated without the need to tear out all of your drywall. That’s because the installation can be done from the outside, no matter what kind of siding you have.
Working with Finished Walls vs. Open Stud Walls
As mentioned, spray foam can be retrofitted into finished walls, and it is even better if you are able to incorporate this process into a renovation or new build. When mid-process, don’t forget to include insulation as part of the budget. When filling wall cavities and covering adjoining wall studs, it’s important to start at the bottom to prevent air pockets from forming. Air pockets can cause excess insulation to leak, causing negative effects. It must also be applied consistently and evenly throughout the wall cavity; otherwise there can be overfill, causing damage to the wall and bulging from the excess insulation.
Benefits of Adding Spray Foam to Existing Walls
Energy Efficiency and Lower Utility Bills
Spray to savespray foam increases energy efficiency by trapping cold or hot air in your home or business space, meaning you won’t have to spend as much on heating or air conditioning.
Moisture and Mold Resistance
Spray foam also improves mold resistance, as the spray fills up holes that would let in rain, humidity, or moisture. Over time, that can build up to be an expensive issue, and one that can be hazardous to health.
Soundproofing and Privacy
Increase efficiency in an office and improve sleep at home through insulation, which improves soundproofing room to room. Better privacy is better for more rest and work.
Long-Term Durability and Value
As an extra cost that is spent on one of your most prized assets — your home or business — spray foam also returns the favor by increasing the durability and value of your house or workspace.
Considerations Before Installing Spray Foam in Existing Walls
Cost Factors
A few factors dictate the cost of a project. How large is the space that needs to be insulated? What is its square footage? What are the wall types? How accessible is the given area where work will be done? Is this project for new or existing walls? A professional team can help assess these to give an accurate quote.
Structural Conditions
Structural conditions also determine cost. Older homes may require some more elbow grease than a new build — working around knob-and-tube wiring, for example, will increase the time and delicacy needed for executing a project. Plaster walls will be easier to drill into to fill with spray than others, so everything from building and wall to electrical type will play a role in dictating budget.
Temporary Disruption
Clients should also know that there will be some temporary disruption to their space during this process. Some jobs take just a day, but larger ones may require more time as workers move room to room to execute.
Comparing Spray Foam to Other Retrofit Options
Spray Foam vs. Fiberglass Blown-In
Generally, spray foam is superior to fiberglass blown-in as it offers a higher R-value. The higher this metric, the better the insulation. Spray foam has a significantly higher R-value per inch compared to fiberglass. This translates to better thermal resistance, leading to a more comfortable home and lower utility costs.
Spray Foam vs. Cellulose
Spray foam also has a higher R-value than cellulose as the foam is engineered for efficiency while cellulose is composed primarily of recycled paper products treated with fire retardants. As such, it does not mix as well with water, leading to more mold.
Why Spray Foam Delivers Better Long-Term Results
Known for its durability, spray foam insulation lasts for decades. It is generally a little more expensive, but it is a highly worthwhile cost as it lasts in the long run while fiberglass can deteriorate and cellulose can suffer from water mixing and thus moulding.
Safety and Professional Installation
Why DIY Isn’t Recommended for Existing Wall Applications
Many home projects are DIY-friendly, but spray foam should be left to professionals because to over-spray can warp walls and to under-spray can make the job null and void. The spray’s inherent chemicals also require their own safety measures, which professionals know how to handle.
Safety Gear and Ventilation Requirements
Professionals know that working with existing walls can make spray foam a more rigorous job, which is why Precision Spray Foam & Insulation recommends hiring experts, who have the safety gear and understand ventilation requirements to do the job right (and safely) the first time.
How Professional Installers Ensure a Seamless Job
Professional installers will start by hearing about your needs, checking out the existing wall structure, and then offering a fair quote. From there, a schedule will be discussed to ensure the job is as efficient and out-of-your-way as possible, so that when you return, you hardly notice anything has changed at all! The only thing that will be different is an improved home or business with new insulation to decrease energy bills and increase property value.
Frequently Asked Questions
Do I need to remove drywall to add spray foam?
No, you don’t have to remove dry wall — instead, you just need to drill holes into it, spray the foam into them, and then patch them up.
How much does it cost to insulate existing walls with spray foam?
The cost can vary depending on the size of the job, type of walling material, and age of the walls and property.
Will spray foam damage existing wiring or plumbing?
Not when you work with experts, who will know how to work around and safely install spray foam so it does not inhibit any existing wiring or plumbing.
Can you insulate only certain rooms instead of the whole house?
Yes, you can go room by room — it is recommended to insulate as much of a home as possible, to increase its energy efficiency, but a job can be done at any scale.
Final Thoughts
Spray foam can be added to existing walls safely and effectively — there is no need to remove dry walls, and it can even be added to exterior walls too. Home and business owners prioritize this service because of its cost-saving benefits, including energy bill savings and increased property value. Insulation also improves comfort, soundproofing, and privacy in a space while also offering long-term protection and better mold and moisture resistance.
Call-to-action“Thinking about upgrading your existing walls with spray foam insulation? Contact Precision Spray Foam & Insulation today for a free consultation in Bergen, Rockland, or Westchester County.”