home exterior insulation contractor installation
July 14, 2020

It’s the thing you’ve been putting off for years. There’s that one room in your home that’s impossible to keep comfortable, brutally hot in the summer and freezing cold in the winter. You know that installing new insulation will help stabilize indoor temperatures throughout the year, but you’re worried about what that might mean for your finished walls.

Well, what if we told you that you don’t have to tear apart your existing walls in order to install new, much-needed insulation? Rather than removing walls and reapplying drywall, if your walls are empty, you can have insulation injected through small holes from either inside or outside.

3 Ways to Insulate Existing Walls

With a small hole ranging from ½”-2”, certain types of insulation can be injected directly into a wall cavity. The three main materials used to insulate existing walls are cellulose, open cell spray foam and close cell spray foam.


Cellulose is made from recycled newsprint and comes in a loose fill form that can be blown into existing walls until it is densely pack aka dense pack cellulose. We often use cellulose in retrofit work because it can be dense packed to provide excellent thermal resistance. New cellulose can be retroactively added to a previously insulated wall that already has cellulose but which has settled over time. Though holes need to be less frequent they are a bit larger at closer to 2” in diameter. Another benefit of cellulose is that it’s typically treated to resist fire, mold, and pests. Unfortunately, cellulose cannot be added to a wall that has already been insulated with fiberglass.

Spray foam

Injection Spray foam insulation is applied as a liquid and very slowly expands in size. Much unlike spray-in-place foam which expands in seconds. The slow rise of injection foam allows it to fill even the tiniest holes and cracks. This makes it a great candidate for insulating existing walls — especially walls where you know there are air leaks, but also means it can leak out in unexpected areas. Preparation is key to a successful injection job. With injection foam there needs to be more holes but the holes can be relatively small, like less than 1” diameter. Close cell injection take longer time as it needs to be done in smaller sections at a time, but has a higher Rvalue than open cell injection foam. One great benefit of injecting foam is the incorporation of an infrared camera to verify that a cavity is full, since foam creates heat as it cures. Unfortunately, spray foam cannot be added to a wall that has already been insulated with fiberglass.

Don’t Forget about the Attic

Remember: your walls are not the only parts of your home that need insulation. In fact, one of the most beneficial areas that homeowners in Vermont, New Hampshire, and Massachusetts can insulate is the attic. Proper attic sealing and insulation offers benefits for the entire home, including greater overall comfort, more efficient heating and cooling, and lower utility bills.

Attic insulation doesn’t require any disturbing any drywall, so it’s another simple project you can tackle first on that home improvement list!

Retrofit Insulation Work Is Best Handled by a Professional

Installing insulation in existing walls with minimal damage is an intricate process, and therefore it’s best left to a professional. At Vermont Foam Insulation, we have the equipment and expertise necessary to increase your home’s energy efficiency, without the mess of tearing down walls. We can even assess the insulation in your walls beforehand with an energy audit, so you know exactly how much insulation your walls need.

Start enjoying greater home comfort and efficiency — without the mess. Call 802-367-3113 or contact us to get a free estimate for your wall insulation project!

You don’t have to tear down your walls to re-insulate.

Ask us about insulation for existing walls!


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Insulation Rebates with ENERGY STAR®

green home savings

Earn up to $5,500 in Efficiency Vermont rebates when you make your home more energy efficient with insulation. Learn about valuable incentives for attic insulation, basement insulation, and other improvements. Vermont Foam Insulation is a trusted insulation expert in southern VT.

Vermont & New Hampshire's Premier Insulation Contractor

vermont foam insulation contractor applies spray foam

Get top-notch insulation services for your home. Vermont Foam Insulation provides eco-friendly options, including spray foam, cellulose, mineral wool, and fiberglass batting insulation. Call us today to schedule a free site visit.