The easiest option to address concerns of high cooling and heating expenses and uncomfortable rooms is to insulate your existing walls.

The more important question is—what type of house insulation is best for exterior walls?  It all depends on how much you wish to renovate, what you want to do, and your budget and expectations.

Open Exterior Wall Insulation

What type of insulation is best for exposed and open outside walls?

Several variables are at play here, but it depends on your expectations. Do you plan to save money or get the best for your walls? Are you concerned about energy efficiency and lowering your carbon footprint?

Let’s look at the many types of outside wall insulation available.

Fiberglass Insulation

One of the solutions that will necessitate ripping down your walls is fiberglass insulation.

The material is made of extremely tiny glass fibers. It would be inserted into the stud cavities as batts or rolls. While fiberglass helps limit cold and hot air spreading, it also allows airflow into and out of the house.

Fiberglass is a low-cost external wall insulation alternative that you can install yourself if you’re confident in your abilities. On the downside, fiberglass has a reputation for drooping and moving over time, indicating that the material has an expiration date and will need to be replaced.

This recurrent cost, combined with upgrading your walls and the equipment required for a DIY project, makes the less expensive choice considerably more costly.

Foam Board Insulation

Another substance that will require you to install when remodeling or, if you wouldn’t mind tearing the drywall out is foam board insulation.

Foam boards are rigid panels constructed of polyurethane, polystyrene, or polyisocyanurate. These boards are sold in various lengths and facings to suit the wall cavities.

But, unlike fiberglass, it’s a one-time deal. After installing the foam board, you won’t need to replace it or engage a contractor to do it. Keep in mind that you must seal around the board seams to prevent significant air leakage.

Spray Foam Insulation

Go with spray foam if you want to establish an air seal to help keep your home at a consistent temperature.

Spray foam insulation for open-wall cavities is an environment-friendly solution. Spray foam is blended with a chemical agent or water, depending on the producer and the material.

Open-cell spray foam is commonly recommended for residential installations. It expands and fills the cavity. However, closed-cell foam is better suited for walls that are exposed. It’s also more durable.

Spray foam will restrict air from moving in and out of your walls, making the house more energy-efficient and comfortable.

Insulation Options for Existing Enclosed Walls

Maybe remodeling isn’t your thing, and it’s not in your budget.

That’s fine since you can still insulate your home without tearing it apart. There is no need to remove any drywall when installing blown-in cellulose or injection foam insulation from outside your home.

Let’s check out the benefits of both solutions.

Cellulose Blown-in Insulation

Without pulling it apart, you may still add insulation to your home if a comprehensive redesign isn’t what you want.

The installation of blown-in cellulose can be done from outside your home. A row of siding will be removed, holes will be drilled in the sheathing, and cellulose will be blown in.

This method does not need to break apart your home, although it can be messy.

Recycled denim or newspaper are used to make cellulose. Dust can be pushed into vents and outlets due to its material nature, causing it to spread throughout your home.

Injection Foam Insulation

Injection foam insulation is put in the same way as blown-in cellulose insulation.

This tri polymer-based resin produces injection foam insulation when combined with water and a foaming agent. When injected into the wall, it has shaving cream-like consistency and fills up every corner.

Compared to other insulation options for existing walls, injection foam stands out since it is the only one that generates an air seal. This air seal maintains the heated or cooled air inside where it belongs.

The air-seal improves the comfort and energy efficiency of your house.

Since injection foam does not require replacement over time, you can ensure insulation coverage in your existing walls.

Final Thoughts

Foam insulation is the perfect alternative for your project if you want to build an air seal within your existing external walls without renovating your property.

On the other hand, if you’re looking for a cheap way to get insulation for the walls and aren’t concerned with energy efficiency or general comfort, one of the other choices would be ideal.