Friday, September 13, 2019

Understanding Spray Foam Insulation

When building an energy-efficient, net-zero home in Missouri, it is vital to eliminate or significantly reduce energy loss with a high-performance thermal envelope. Spray foam insulation, an alternative to traditional building insulation such as fiberglass, saves on energy costs and dramatically lowers utility bills.
Studies by the US Department of Energy show that 40% of a home’s energy is lost as the result of air infiltration through walls, windows, and doorways. Buildings treated with spray foam insulation typically insulate as much as 50% better than traditional insulation products.

Spray Foam insulation blocks all three forms of heat transfer:
  • Conductive heat transfer – The flow of thermal energy through a substance from a higher to a lower temperature area.
  • Radiant heat transfer – The process by which heat energy in the form of light is emitted more strongly by warm surfaces and absorbed by other materials, especially those of low IR reflectivity.
  • Convective heat transfer – Heat which is created elsewhere that is transported utilizing a fluid, such as water or in our case air.

How it Works

Spray foam insulation has a two-part spray process, starting with two 55 gallon drums – one with urethane material, and water-based blowing agent in the other.
Two chemicals mix at the spray nozzle and instantly expands to 100X applied thickness, adhering to the sprayed surface, and filling all gaps and voids to make an excellent air barrier.
Open Cell Foam –
  • Air barrier, but water vapor permeable
  • Primarily used on interior applications against the wood to prevent condensation from being trapped against the framing.

Closed Cell Foam –
  • Air and water vapor barrier
  • Primarily used on exterior applications where a vapor barrier is needed, i.e., crawlspaces
  • Approximately 2X cost of open-cell foam

Spray Foam Insulation Pros & Cons

The Good
  • Excellent air sealing
  • Easy retrofit in the attic
  • Places insulation at the roof deck
    • puts mechanicals inside conditioned space
  • Keeps loft within 8-10° of living space
  • Reduces mechanical sizing requirements
  • Approximately 25% energy reduction

The Bad

  • Contains polyurethane
  • Off-gasses VOCs for a couple of days
  • When applied to full-fill walls, can result in lots of landfill trash
  • More costly than batt insulation

4 Things to Remember When Buying Spray Foam Insulation

The most common question from homeowners researching spray foam insulation I hear is, “How much does spray foam insulation cost?” Much like buying a vehicle, various factors can influence the final cost per square foot of a spray foam insulation installation. Below are four things to remember before ordering spray foam insulation.

Image result for spraying foam insulationLabor: Remember to factor in the cost of the spray foam contractor’s labor. Unlike painting, spray foam insulation is not a DIY project and requires a certified professional to apply the material.

Quantity: How much material will be needed to complete the job? The open-cell spray can cover more surface area than closed cell spray foam insulation. This is due to the soft, sponge-like texture that expands up to 100 times its initial volume while closed-cell can expand between 40 and 60 times its initial size when applied. This means more material is required to cover the space. The required thickness of the material, dictated by building code or area of the home, will also contribute to how much material is needed.

Spray Foam Type: What kind of spray foam needs to be utilized for the project? Does the project require closed-cell insulation or open-cell spray foam insulation? Open-cell spray foam insulation is more cost-effective than closed-cell and is effective in residential projects in providing thermal comfort, air-sealing, and moisture management.

Location/Climate: Southern climates are different from northern climates. Closed-cell spray foam is typically used in areas prone to flooding (since closed cell is recognized by FEMA as a flood-resistant material), while open cell is a great option for southern climates due to its ability to breathe.
To find out your total cost to install spray foam insulation, the licensed spray foam professionals at ArmorThane are happy to give you a free estimate for your upcoming project. Call ArmorThane, Springfield branch, at 417) 831-5090 or visit their website at