Where is a draftstop commonly installed to restrict air movement within concealed areas?

A draftstop is a critical component used in building construction to control air movement and improve energy efficiency within concealed spaces. Its primary function is to create barriers that minimize air leakage, which can lead to energy loss and potential moisture issues.

In attics, draftstops can help prevent warm air from rising and escaping into unconditioned spaces, ensuring that the heating or cooling efforts in the living areas below are not wasted. This is essential for maintaining energy efficiency and comfort within the building.

In crawl spaces, draftstops serve a similar purpose by restricting the unwanted flow of air that can lead to temperature fluctuations or moisture accumulation. By sealing off these areas, the overall health of the building can be improved, reducing the risk of mold and deterioration.

Additionally, in floor/ceiling assemblies, draftstops play a vital role in controlling air movement between different levels of a building. This is particularly important in multi-story buildings where air circulation needs to be managed to maintain comfort and efficiency throughout.

Since draftstops are suitable for installation in all these spaces—attics, crawl spaces, and floor/ceiling assemblies—option D, indicating that all these areas can benefit from the use of draftstops, is the most comprehensive and accurate answer.