How Much Does Attic Insulation Cost?

by Team HomeServe
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As a homeowner, you should always be on the lookout for ways you can boost the value of your home and save money in the process. Attic insulation is a great way to save money on your utility bills and keep your home comfortable.

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Insulation installation costs vary widely depending on the type and amount of insulation being put in. This guide will help you estimate what your project will cost.

What Is Insulation?

Many homeowners have insulation in their attics and aren’t even aware of what it’s made of or what it does. Insulation is material designed to prevent heat or sound from being transmitted from one area to another. It's normally used to keep heat and/or sound in or out of your home or to confine it to certain parts of your house.

The reason why it’s so common to see insulation in attics is because warm and cool air often flow through the attic. Left unchecked, this air can freely make its way through your home. While this may not seem like a big deal at first, it can lead to warm homes in the summertime and cold homes in the winter. This means your air conditioning unit or heating system will have to work overtime to keep your home comfortable, causing a spike in your utility bills.

Why Install Insulation in Your Attic

You may be looking at the price of attic insulation and wondering whether it’s worth it. While this is a common question asked by homeowners, the price of insulation pales in comparison to the price of the energy bill in a home without insulation. To better understand why insulation is so important and why it helps save homeowners money, you must first understand how heat flows throughout your home. Heat makes its way through your home in three different ways:

  • Conduction: Heat moves through materials.
  • Convection: Heat circulates through liquids and gases.
  • Radiation: Heat travels in a straight line and heats anything solid in its path.

Most common insulation materials work by slowing conductive heat flow. Regardless of the mechanism, heat flows from warmer to cooler until there's no longer a temperature difference.

To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.

Costs of Insulating Your Attic

There are several key factors that will determine how much you can expect to pay for insulation installation. First and foremost, you need to decide if you're replacing old insulation or installing completely new insulation. If you're replacing old insulation — which is the case for most homeowners — you'll need to assess your current situation.

Wet or damp insulation and mold or rotted rafters may be indicative of moisture problems, potentially stemming from a roof leak, which should be addressed before installing insulation. This will require you to reseal your attic.

After assessing your current situation, you'll then need to decide what type of insulation best fits the needs of your home. There are several types of insulation, each with its own individual pros and cons. We'll go into further detail about the different types of insulation later in this article. Understanding the key factors that go into insulation costs will help you properly set your budget.

Attic Insulation Cost Estimates

The price of attic insulation can vary greatly depending on the size of your attic, the material, and your location. This makes it difficult to pinpoint an average cost for homeowners across the country. With that being said, HomeGuide estimates that insulating an attic costs anywhere from $500 to $6,000 (CAD 683 to CAD 8,194) or between $0.80 and $12 (CAD 1.09 and CAD 16.39) per foot.

Depending on the difficulty of the job, the size of your attic and the type of insulation material used, the final cost for professional placement will likely fall between $1 and $4 (CAD 1.37 and CAD 5.46) per foot. You'll also need to consider the labor cost that comes with installation, as well as any replacement service fees or repairs that come with replacements. Because of the cost of labor, many homeowners choose to install their attic insulation themselves.

How Much Insulation Do I Need?

Believe it or not, 90% of homes in the United States are considered under-insulated, so the home doesn't have the protection it needs. You can find out whether your attic is under-insulated by having it inspected. The proper amount of insulation needed in your attic will vary depending on two key factors:

  • Where you live: Different climates will require different insulation R-values. R-values range from 2.0 to 8.0 per inch of insulation. The higher the value, the better the job the insulation does, and the more extreme the climate, the higher the R-value needs to be.
  • The age of your home: The older your home, the more insulation you'll need. You can retrofit your home with fiberglass and mineral wool insulation if needed.

The type of insulation material will also play a big role in your insulation’s R-value. Additionally, the size of your attic will play a large role in the amount of insulation you need. If you're unsure, consult with an expert. The last thing you want to do is spend far too much money or not get enough and have to make multiple trips to the store.

Attic Space Insulation Costs by Square Feet

As mentioned earlier in the article, you can expect to pay anywhere between $0.80 and $12 (CAD 1.09 and CAD 16.39) per square foot for insulation. Then, you need to factor in installation costs. Forbes says you can expect to pay an attic insulation installer about $70 (CAD 96) per hour. In some cases, you may also need the expertise of an electrician to safely insulate around junction boxes or cables. According to This Old House, you can expect to pay an additional $40 to $120 (CAD 55 to CAD 164) per hour for this service.

Depending on the difficulty of your job, the size of your attic and the type of insulation material you decide to use, the final cost for professional placement will likely fall between $0.50 and $1.30 (CAD 0.68 and CAD 1.78) per square foot. There are some rebates and savings you can benefit from when installing insulation as well. Some states offer weatherization rebates, discounts and other incentives for insulating your home.

Types of Insulation and Material Costs

There are three major types of insulation. Each provides its own benefits, and each has a different price. It’s important to understand the differences between these materials to ensure you make the correct decision. The three different types of insulation materials and their prices are described below.

Blown-In Insulation

Loose-fill (blown-in) insulation is sold in large bags containing tiny chunks of cellulose, fiberglass or mineral wool fiber, which a professional installer will use a blowing machine to install. This is the ideal solution if you’re looking to fill small, empty areas and gaps. The price of blown-in insulation ranges from $0.90 to $2.40 (CAD 1.23 to CAD 3.28) per square foot.

Experts recommend using this option in attics with irregular framing or obstructions between joists and older attics that already have some insulation and are simply in need of a touch-up. The average cost of installing loose-fill insulation in your attic falls between $1,100 and $3,800 (CAD 1,502 and CAD 5,189).

Spray Foam Insulation

Spray foam insulation is the most expensive insulation, and it's available in open-cell and closed-cell options. Open-cell foam insulation is the less expensive option, but it doesn't provide any vapor barriers. The closed-cell option may be more expensive, but it's denser and provides a strong barrier against air and water. While this option may be expensive, it’s perhaps the highest-quality material available.

This is the recommended option for those looking for insulation against noise, new construction and outdoor applications. In fact, spray foam insulation is most easily installed in newly constructed homes. The average cost for spray foam insulation installation falls between $1,100 and $9,000 (CAD 1,502 and CAD 12,291).

Batt Insulation

Batt insulation consists of long rolls of insulation fibers that are held together with a paper or reflective foil backing. The insulation fibers may be fiberglass, cellulose, mineral wool or even recycled blue jeans. This type of insulation is great for covering a wide area, but it’s difficult to install in tight places and small gaps.

This is the recommended option for attics with a standard spacing of joists and new construction free of obstructions or existing insulation. The average cost of batt insulation installation for homeowners in the United States ranges from $1,100 to $3,900 (CAD 1,502 to CAD 5,326).

Removing and Replacing Existing Insulation Costs

Luckily for homeowners, experts suggest that it’s highly unlikely that you'll need to completely remove and replace your insulation. In fact, most experts strongly recommend against completely removing and replacing your insulation unless it’s absolutely necessary. Unless your insulation has mold or animal feces, you should weigh your options before committing to completely removing and replacing insulation.

The estimated cost of removing old insulation is $1 to $2 (CAD 1.37 to CAD 2.73) per square foot. Keep in mind that this is on top of the price of installing your new insulation. You can remove your insulation yourself, but if there are signs of mold, it’s highly recommended that you seek professional help. Mold can be dangerous, and it needs to be disposed of properly to ensure the safety of you and your family.

DIY Attic Insulation

Attic insulation is one of the most common DIY home renovation projects homeowners take on. This is because it can help save you 10% to 50% on your energy bill, and it’s one of the easiest home renovation projects. First and foremost, you need to get an accurate estimate of how much you need and what type you need. Next, you'll need to protect yourself by wearing a dust mask, avoiding standing on joists and illuminating dark corners. Once you’re all set up and ready to go, follow these steps to insulate your attic:

1. Seal any air leaks: Any gaps in the attic will let hot or cool air escape, making any insulation you add essentially useless.

2. Other prep steps: Make sure any leaks are fixed, box out any light fixtures and direct all exhaust fans and vents to the exterior.

The other steps you'll take depend on the type of insulation you're installing:

  • Loose-fill: If you’re installing loose-fill insulation, make sure the fill's depth is uniform across the attic. To help the material achieve the right density as you install it, hold the blower hose parallel to the floor and the floor joists. Blow in the fill between and over the joists rather than across them.
  • Batts: Make sure you're using unfaced backs. You can buy them unfaced, or you can remove the paper or foil backing. Place a new layer of unfaced batts perpendicular to the old layer to cover any gaps in the lower layer. Adjoining batts should be butted snugly together, but not tight enough to compress them. Don't leave any gaps between batts and joists, obstructions or abutting batts. Even narrow ones will let air escape. Instead, cut a thin strip of the insulation you're using to size.

If you are unsure whether you can complete this project on your own, don’t be afraid to seek the help of a professional insulation company. Professionals are trained and experienced in the industry and will ensure that the installation is handled properly. They can also complete the job in a few hours, while it may take you a few days.

All CAD conversions are based on the exchange rate on the date of publication.