Frequently Asked Questions

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The "R-value" in insulation refers to its thermal resistance or how well it can resist  the flow of heat. It measures the insulation's ability to reduce the transfer of thermal energy between two surfaces. The higher the R-value, the greater the insulation's effectiveness in preventing heat transfer. It is an important factor to consider when selecting insulation for buildings or homes to maximize energy efficiency and maintain comfortable indoor temperatures.

Batt insulation comes in pre-cut sheets and is installed by fitting the insulation between the studs, while blown-in insulation is installed using a machine that blows the insulation into the desired area. Blown-in insulation is typically used for hard-to-reach areas and can provide better coverage than batt insulation.

Spray foam insulation and fiberglass insulation have different properties that make them better suited for different situations. While it is generally true that spray foam at R21 has a lower R-value than fiberglass at R30, the R-value alone does not determine the overall effectiveness of an insulation material. Here are a few factors to consider:  

1. Air Sealing: Spray foam insulation is effective at sealing air leaks due to its ability to expand and fill gaps, cracks, and crevices. Fiberglass insulation, on the other hand, can leave gaps and may not provide a complete air seal.  

2. Moisture Resistance: Spray foam insulation is resistant to moisture, making it a good choice for areas prone to water leaks or high humidity. Fiberglass insulation can absorb moisture, leading to potential mold or mildew issues.  

3. Thermal Performance: Spray foam insulation provides a higher level of thermal resistance per inch compared to fiberglass. This means that even though the R-value may be lower, spray foam can provide better insulation due to its ability to limit air movement and provide a continuous barrier.  

4. Installation: Fiberglass insulation is typically easier to install and more cost-effective. It can be rolled out or placed in batts between studs or in attics. Spray foam insulation requires professional installation and can be more expensive. While spray foam at R21 may have a lower R-value than fiberglass at R30, it can provide better overall insulation performance due to its air-sealing capabilities, moisture resistance, and thermal performance. However, the choice between the two ultimately depends on the specific needs and requirements of your project.