Which of the following statements is true regarding the application of spray foam insulation?

Spray foam insulation is particularly advantageous due to its ability to fill gaps and irregular spaces effectively, making it suitable for application in confined spaces. The foam expands upon application, allowing it to conform to various shapes and sizes, thereby providing a tight seal that helps improve energy efficiency and air quality. This characteristic is one of the main reasons contractors often recommend it, as it significantly enhances insulation performance over traditional materials.

In contrast, other options present limitations or misunderstandings about spray foam insulation. While there may be situations where a professional should oversee the application for safety and effectiveness, it is not strictly limited to professional use. The curing time for spray foam generally varies based on product type and environmental conditions but is often shorter than implied by the option concerning lengthy curing times. Lastly, spray foam insulation is frequently used in retrofitting applications to upgrade existing buildings' insulation without the need for significant renovations, demonstrating its versatility and adaptability.