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6 Benefits of Spray Foam Insulation: Is it the Smart Choice for Your Home?

Man spraying spray foam insulation in between wall studs to insulate the basement wall

While most every home today plays host to an array of electronic devices it is not the widescreen TVs, sound system, track lighting, security cams, refrigerators, microwaves, toasters, blenders, myriad smartphones, laptops, tablets or the PC that account for the bulk of a home’s energy costs. It’s heating and cooling.

The average cost of heating a home with oil in Massachusetts, for instance, was estimated to be $2,278 for the 2017/18 heating season (Source). And with oil continuing to rise in price 2018/19 looks like it’s going to be even worse. While it’s true Massachusetts is just one state they are nonetheless fairly representative of what homeowners in the other northern tier states can expect. But are such outrageous heating costs inevitable? Or is there something that can be done about it?

Origins of the Insulation Gap

For decades the value of insulation in reducing energy consumption has been well known. Yet still there are still a vast number of homes in North America that are not properly insulated. There are two main reasons for this. Either they were:

  1. built in the days prior to modern concerns about energy consumption or
  2. builders now are attempting to rein in construction costs by cutting corners on insulation.

In either case the result is that many homeowners are paying more for energy than they need to.

Man putting in fiberglass insulation in attic


Insulation Options

Today’s homeowner has a variety of insulation options when it comes to insulation, including:

1. Cellulose

Cellulose insulation is made from about 85% shredded, recycled newspaper with 15% being a mineral compound that acts as a fire retardant. These mineral compounds, or “borates”, also help prevent the growth of mold and inhibit the activity of pests who might otherwise want to set up house in the warm, fluffy shredded newspaper.

Photo a home with regular fiberglass insulation in the walls.

2. Mineral Wool

Mineral wool (Source) is made from basalt and recycled slag. It’s not really wool at all but called that because the final product – which is the result of spinning and drawing molten forms of the aforementioned slag and basalt – tends to resemble wool. Most forms of mineral wool pose a health risk similar to fiberglass. Although there is no such health risk associated with the rigid-board form of mineral wool.

3. Fiberglass

Fiberglass is the most widely used form of insulation in homes today. In part because it is relatively easy to install and in part because it’s very affordable. Some manufacturers have taken tentative steps to address the risks associated with fiberglass fibres although these manufacturers are still in the minority.

4. Spray Foam Insulation

Spray foam insulation is a form of polyurethane that is mixed on site then sprayed into the space between floor, wall and ceiling joists. To mix the chemicals (typically referred to as components “A” and “B”) special truck mounted equipment is used to convey the A and B components through heated hoses to the gun where they are combined and then sprayed onto the surface to be insulated. As soon as the mixed compound hits the surface it begins to expand, forcing its way into even the tiniest crevices before hardening. There are two types of spray foam insulation. They are:

Photo of a wall with spray foam insulation

5. Closed cell

Closed cell spray foam is denser than open cell. Upon setting it becomes very hard and has an outstanding R-value. Because it is so dense closed cell spray foam forms an effective air barrier when set. It also tends to create a more effective moisture barrier than open cell. But it can be considerably more expensive.

6. Open cell

Open cell spray foam is light but incredibly effective. It expands aggressively as soon as it touches the surface leaving no crack or crevice unfilled. Open cell is typically used for most domestic applications.

6 Key Spray Foam Insulation Benefits

For many years spray foam insulation was used almost exclusively in commercial settings but recently that has begun to change. As word has slowly spread about the many advantages of spray foam insulation more and more homeowners are choosing it over fiberglass and it’s easy to understand why. Unlike fiberglass spray foam:

  • Provides an effective air and moisture barrier.
  • Adds structural integrity to walls, floors and ceilings.
  • Reduces the amount of pollen that infiltrates the home.
  • Will remain effective even if it gets wet due to a burst pipe or flood.
  • Provides a higher R-value.

Let’s expand on those advantages a bit.

  • Air Barrier – No matter how snugly that roll of fiberglass fits into the space it will always leave some room around the edges and at the seams for air to infiltrate. Not so with spray foam. Spray foam pushes itself into even the tiniest crack or crevice. Air simply has nowhere to go.
  • Moisture Barrier – While it’s important to seal your home against the wind it’s just as important to seal it against moisture. While most forms of insulation do a poor job of preventing moisture from infiltrating the home spray foam stands tall against moisture. Your entire house will be drier, healthier and more comfortable.
  • Enhanced Structural Integrity – A house is only as strong as its frame and most forms of insulation do nothing to enhance the ability of the home to stand up to Mother Nature’s wrath. By grabbing hold of walls and floors by expanding into and filling cracks and crevices spray foam essentially becomes one with the surface you spray it on, adding its strength to that of the wall, floor or ceiling.
  • Reduces Pollen Infiltration – It’s hard to believe but a good portion of the pollen in a given house did not get there through an open window or door. It got there through the walls. By insulating your exterior walls with spray foam insulation you virtually eliminate air leaks and the pollen that they allow in.
  • Remains Effective Even When Wet – If a pipe bursts or your home is subjected to flooding the insulation in your walls that got wet will need to be ripped out and replaced. Unless it was spray foam. Spray foam insulation is impermeable to water and retains its insulating capabilities regardless of how wet it gets.
  • Higher R-Values – The bullet list below shows the different types of insulation commonly used in the home and their R-values. Note which material wins the day.

Insulation Type & R-Value per Inch

  • Fiberglass: loose – 2.2 – 2.9 R-Value per inch
  • Fiberglass: batts – 2.9 – 3.8 R-Value per inch
  • Cellulose – 3.1 – 3.8 R-Value per inch
  • Mineral Wool: loose – 2.2 – 3.3 R-Value per inch
  • Mineral Wool: batts – 3.3 – 4.2 R-Value per inch
  • Cotton: batts – 3.0 – 3.7 R-Value per inch
  • Spray Foam – 5.6 – 8.0 R-Value per inch

Where can spray foam insulation be used in the home?

  • The Attic – Attics are a major source of heat transfer. When you insulate your attic using spray foam you prevent hot air from escaping through the roof during the winter months and cold air from intruding. In the summer you prevent hot air from infiltrating and cool air from escaping.
  • Exterior Walls – Insulating your exterior walls with spray foam provides the aforementioned air and moisture barriers, prevents water from leaking through cracks during heavy weather events and buttresses the structural integrity of the entire house.
  • Basement – Most basements are perpetually damp and cool and a favourite breeding ground for dangerous molds and bacteria. Sealing the walls of the basement using spray foam creates a drier, safer, warmer and healthier basement.
  • Interior Walls – Insulating interior walls with spray foam before covering them with drywall not only prevents heat leaking from warmer to cooler rooms it also provides an effective noise barrier. Good news for modern homes and their notoriously thin walls.

Wrapping it up

Spray foam insulation is the wise choice for homeowners who want a drier, warmer, more energy efficient, healthier and stronger home. It will undoubtedly cost a bit more than fiberglass but the savings you enjoy over time should more than make up for the difference. Talk to your local insulation specialist about the possibility of installing spray foam insulation in your home.