Insulation and Spray Foam Frequently Asked Questions

Some spray foam is waterproof, but not all. Specifically, open-cell foam is not waterproof, but it is water-resistant. Closed-cell foam is also water-resistant, but only the higher-density closed-cell foams are truly waterproof.

Applying a closed-cell, waterproof spray foam can be an important addition to homes and commercial properties to keep excess moisture out. Moisture can be found in the presence of mold and mildew, which can lead to an expensive repair.

To prevent water damage to your property, our team recommends utilizing closed-cell spray foam to, essentially, waterproof your space to protect it from water damage.

The thickness of your spray foam is based on the type of spray foam you’ve chosen for your application. So, yes, 2 inches of spray foam is enough in certain situations while using a particular type of foam, but it is not a universally accepted standard for sufficiency. When using closed-cell foam in walls, it is generally considered sufficient when 2 to 3 inches are sprayed.

Open-cell foam in walls would not be sufficient with just 2 inches, as it requires at least 3. Sprayed into attics, closed-cell foam is recommended to be between 4 and 5 inches, while open-cell foam ceiling and roof spraying should fall somewhere in the 6- to 10-inch range.

The amount of square feet spray foam can cover is dependent on a variety of factors, including the pressure of the output, the type of spray foam, and more. On average, though, one can (just over 27 oz.) of closed-cell spray foam can cover roughly 25 broad feet.

If you want to learn more about just how much spray foam you would need for a given application, check out this helpful tool for determining the area of wall insulation.

Spray foam insulation cost is generally broken down by square foot and varies in thickness between the various types. Generally speaking, open-cell spray foam will cost between $1 and $1.50 per square foot, while closed-cell insulation runs between $2 and $3 per square foot.  

Yes, there are numerous benefits to utilizing spray foam insulation for your various projects and applications. From an energy-saving perspective, there is little doubt that spray foam insulation is a big money saver. Closed-cell insulation is dense, so when applied to walls and ceilings it can serve a variety of purposes ranging from temperature retention to waterproofing, and even structure stabilization and reinforcement.

On the other hand, open-cell spray foam is a more affordable option, and it expands quickly, filling up the cracks and crevices. Considering its status as being water-resistant, it is highly effective only when there is no chance of moisture seeping in. Its sealing ability does serve as a powerful barrier against insects and pests coming into the home, however.

Spray foam is commonly used in residences and industrial structures and is especially effective as a retrofit product in aging homes. Because the foam is spray applied, almost all substrates are suitable to receive spray foam. Caution should be taken to prevent overfilling areas from causing damage through the force of the expansion. 

Learn about more benefits of spray foam insulation.

Spray foam kits are commonly sold for those who wish to apply spray foam themselves. The spray foam solution is made up of two chemicals (isocyanate and polyol), both of which require certain temperatures to remain stable and viable for application, with most spray kits utilizing a built-in indicator to denote when a temperature is too low.  

There are a few “nonstarter” rules to spraying the insulation as well. It should not be applied to areas rife with moisture, or in sub-50° Fahrenheit temperatures. Because both chemicals involved are abrasive to human skin and other organs, when applying spray foam, gloves, goggles, breathing apparatuses, and full-body coverings are essential for the full safety of the applying party.

Additionally, check out our post to learn more about how to handle spray foam barrel sets.

Every manufacturer will provide a safety data sheet (SDS) along with their product. This will retain information about how long to keep the sprayed area clear. When spray foam is applied, it releases gases and fumes toxic to human consumption, so the area of application should be cleared during the spray foam process (besides the party who is performing the work) and vacated for at least 24 hours after the fact to permit the toxic vapors to dissipate.

On average, it can take anywhere between 8-24 hours for spray foam to completely cure and expand, though it usually takes anywhere between 5 minutes and 1 hour to become tack-free. For the best results, review your spray foam’s product label to determine the optimal curing time for your specific brand and application.

One of the primary advantages of spray foam insulation is its moisture resistance. Mold stems from high moisture levels as it needs moisture to thrive. One of the many useful reasons for using spray foam is to mitigate mold growth.

Therefore , mold will not grow on spray foam insulation. Because spray foam reduces the effects of moisture in the areas it covers, these areas experience less potential for mold growth due to decreased moisture.

The makeup of spray foam insulation has not been found to contain anything that appeals to mice in terms of food. Mice can dig at things and follow the path of least resistance to get inside homes, especially when it gets cold  out, but a tightly sealed set of walls and attic creates a more divisive barrier that greatly reduces the chances of mice coming in.

If mice are already inside when the spray foam is applied, that is a problem of a different sort. Theoretically, the mice can claw at and bite at the spray foam, though it may be detrimental to their health (which might make them stop) and it will take too much effort, leading them to potentially abandon their cause. 

Whether it is professionally applied, or you do it yourself, you might be looking at thousands of dollars’ worth of expenses for your project. Knowing this, you can be prepared to compare it to your energy bills and estimate any repair or pest control expenses you could potentially be looking at and add up that amount.

Suppose you can break down those investments by month. In that case, you are likely to find that with lower bills and a lack of need for most repairs associated with uninsulated walls and attic, what you spend on the spray foam insulation install will quickly be outweighed by the other expenses.

Depending on the situation, this may take a different number of months for various people, but it is a safe bet that the upfront expenses will soon pay for themselves. 

Yes, spray foam, such as spray polyurethane foam (SPF), provides a sustainable solution for homes and commercial buildings. Though more of a concern in the past, harmful, CFC blowing agents have since been replaced with HFOs, resulting in a substantial decrease in the Global Warming Potential (GWP).