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How to Insulate Existing Walls

By: Amanda Ringler on August 8th, 2017

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How to Insulate Existing Walls

injection foam insulation  |  blown-in cellulose insulation  |  Existing walls insulation  |  insulation

Cold spots and drafty rooms are tell-tale signs you need insulation in your existing walls, but you also need to know how to get the job done.

If you’re also experiencing high monthly energy bills, drafts coming through outlets, cold walls, and the dishes in the exterior wall cabinets are cold, then you need new or updated insulation in your walls.

Unless you are doing a remodel and gutting to the studs, there aren’t too many options for re-insulating existing walls. The two most common ways to insulate existing walls without tearing down drywall is  injection foam and blown-in cellulose.

RetroFoam of Michigan has more than 15 years of experience insulating thousands of existing external walls across Michigan’s lower peninsula, so we have seen it all and know how to fix it all.

In our ongoing efforts to educate homeowners, we have broken down the advantages and disadvantages of each material, the installation process, and how much each one costs.

Blown-In Cellulose Existing Wall Insulation

cellulose

When it comes to adding insulation to existing walls, blown-in cellulose is one of the two main options. It is primarily made from recycled newsprint that conforms to most spaces without disturbing the structure or finish.

Pros and Cons of Blown-In Cellulose Existing Wall Insulation

While blown-in cellulose insulation can be a cheaper option for existing walls, it also has its drawbacks.

Blown-in cellulose in existing walls can add a thermal insulation while providing some level of soundproofing, according to the Energy Audit Blog.

On the downside, the cellulose insulation can spill into the home through any openings in the wall cavities, like electrical sockets and furnace duct systems. Blown-in cellulose also allows for air leakage that contributes to a critical source of a home’s energy loss, as well as drafts, cold floors, and cold walls.

Blown-In Cellulose Insulation Cost

There are several factors that determine the cost of blown-in cellulose insulation. The main factor in this instance would be the cost of hiring a licensed contractor.

The size of the area to be insulated is also another major factor when determining cost.

Injection Foam Existing Wall Insulation

injection foam insulation

Injection foam is an insulation and air barrier that will seal the existing external wall cavities against air movement. Injection foam is made up of a three-part resin designed to insulate enclosed cavities and has the consistency of shaving cream.

Pros and Cons of Injection Foam Existing Wall Insulation

Injection foam insulation tends to be a more expensive option compared to traditional insulation materials, but it does a better job making a home feel more comfortable and lowers monthly energy bills. It also is a cleaner material that doesn’t produce more dust around the home and will improve indoor air quality as it keeps allergens and pollutants from entering the home.

There can be issues with injection foam if the homeowner hires a contractor who doesn’t specialize in the material. If the installers aren’t trained in how to install the injection foam area in the walls can be missed and there could even be damage to the walls.

Injection Foam Insulation Cost

Much like blown-in cellulose, the size of the area to be insulated is the main factor when determining the cost to insulate existing walls with injection foam insulation.

The number of stories in a home and the type of siding are also cost factors.

Injection Foam and Blown-In Cellulose Insulation Installation Process

Reduce energy costs by insulating your whole house

Both injection foam and blown-in cellulose can be installed in existing walls through similar methods.

First a row of siding is removed and then a hole is drilled into each stud cavity. The insulation material is then injected or blown-in until crews know the cavity is full.

RELATED: How Do Crews Know if the Wall Cavity is Full When Injecting Foam Insulation?

The hole is then plugged and the siding is replaced.

Making the Best Insulation Choice for Your Existing Walls

The choice is yours now to decide if dense pack cellulose or injection foam is the better fit for your existing walls insulation needs.

If you want to learn even more about the benefits of foam insulation, check out our learning center. If you have decided injection foam is the best fit and live in Michigan’s lower peninsula, give us a call at 866-900-3626 for a free estimate, or fill out the form on our website.

Ultimate Foam Insulation Buying Guide for Existing Homes