The Downsides of Spray Foam: What you Should Know Before Installing

Big Budget, Big Payoff

The main disadvantage is the cost.

There are two different types of foam used depending on the type of project it’s being used for, and each cost a different amount.

Open-cell spray foam usually used for interior jobs can cost anywhere from$3 to $5 per square foot. Closed-cell foam, used for exterior walls, can cost between $4 to $7 per square foot.

To put that into perspective, spraying a 1,000 sq. ft. basement could cost between $4,000 - $7,000. A 1,200 sq. ft. attic could be as much as $12,000.A 500 sq. ft. garage $3,500.  

In general, a two-story home sprayed on each level including rim joists, cantilevers and ceilings on the top floor will cost between $20,000 and$30,000. Clients with larger homes can often have spray foam jobs that cost upwards of $80,000.

So, that’s quite a bit of money to budget. That said, it will save you more money in the long run.

“It costs a lot up front but really pays off long term; it eventually pays for itself through energy savings and less rework on the insulation down the line,” says Justin.

While it might take close to 15 years before the spray foam investment starts keeping money in your pocket, the energy bill savings can be as much as $50 per month. That’s $600 a year.

After a few years of monthly energy bill savings, the initial investment should be paid off, and then all those savings stays in your pocket.

It’s a Good Time to Take a Little Holiday

Another negative aspect of spray foam is that residents need to vacate the house for along period of time, which can be a big inconvenience.

The foam sets within minutes, but once installed, it needs to be left alone for 24hours to ensure the toxic air vents out of the home. Because the foam is sprayed with a high-pressure machine, some of the raw foam product can create a vapor in the air, so ventilating the home helps ensure client safety.

After the spray foam installation, there is a very minor release of gasses from the cured foam, also known as off gassing, but it’s so small that most of our instruments cannot detect it.

Spraying a full basement can take up to 8hours as it includes foundation walls and rim joists (the section of walls above the ceiling and below the main floor). An entire home can take 3 to 5days, plus the 24-hour vent time. That’s a long time to be out of your home.

“After that the foam is a solid state of plastic, like any other plastic in your home,” says Justin.

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Foam Failure

Even with the perfect conditions, problems with the actual spray foam can arise if it’s installed too thick or too fast.

Closed-cell foam can only be applied in 2-inch passes at a time. If one tries to apply a 5-inch pass, that can cause the internal temperature of the foam to get too hot and combust.

In that instance, however, rushing through a spray foam job and not setting yourself up properly is the problem.

Temperature

In a climate like Calgary, we are not immune to wild weather nor extreme temperature swings (thanks, Chinook!) and as we’ve already learned, temperature plays an important role in spray foam insulation. Like in the Goldilocks and the Three Bears story, spray foam needs temperature conditions to be just right.

In the colder months, spray foam can be installed on a substrate (fancy word for the material being sprayed, such as concrete or wood) as low as –10degrees Celsius.

In the warmer months, spray foam can be installed up to 40 degrees Celsius, but that’s not ideal working conditions for the installer.

Despite all the technical and temperature related issues, the biggest problem that can arise using spray foam is the starting conditions of the site.

The temperature conditions of substrate being sprayed, such as concrete foundation or wood of an exterior wall, are another big downside of spray foam. If it's too cold, the hot temperature of the foam will react to the cold substrate and insulation could literally popoff the wall. If the substrate is too wet, the foam won’t react or adhere properly and create a huge problem also.

“We measure the temperature of the room and the substrate and check the moisture too,” Justin says.

Knowing Who to Call for the Install

Other drawbacks of spray foam have to do with the installers rushing to finish a job or the conditions of the area being sprayed.

Doing research on construction or spray foam companies will save you a lot of headache.

Justin tells a story when a client hired another company to spray their home but left behind raw chemicals all over the floor, leaving the house smelling quite awful.

Beyond Group and several other area companies came to the rescue to fix the problem. It took up to 15 people from across these companies several weeks to rectify the issue.

“Rushing is when mistakes happen.  Our guys know not to rush. If they can’t finish a job in a day, that’s ok. We go back the next day to make sure it’s done right,” says Justin.

Spray foam is becoming so much more popular than traditional insulation that even building codes are catching up. All new homes are spraying rim joists, and cantilevers are more commonly being sprayed in new homes as well.

All these little pockets of space that can be affected by exterior elements typically see a lot of air leakage and moisture, making them difficult areas to install traditional insulation. With spray foam, the difficulty of getting into these tight areas is eliminated, as is the possibility of air leaks or moisture traps.

As previously mentioned, spray foam is an airtight, everlasting compound. Walls within a room installed with spray foam will hold the air longer than traditional batt and poly and the foam maximizes energy usage by holding that air where you want it to be which means you won’t be constantly adjusting your thermostat or air conditioner.

The benefits of spray foam are long term and make it a great investment. As long as these potential drawbacks are considered and managed appropriately, using spray foam can be an excellent insulator for any project.