When placing a window into a rough opening, what is the recommended fit for the window?

When installing a window in a rough opening, the recommended practice is to fit the window loosely. This is important to allow for expansion and contraction of the materials due to changes in temperature and humidity. A tight fit can cause stress on the window frame and potentially lead to damage over time.

Additionally, having a loose fit facilitates the installation of shims, which are used to ensure the window is level and plumb. These shims help provide stability while also allowing for adjustments during the installation process. Furthermore, a loose fit allows for the necessary sealing materials, like caulking and insulation, to be applied effectively. This helps prevent air and water leaks, contributing to the energy efficiency and longevity of the window installation.

In contrast, fitting the window tightly could hinder adequate sealing and insulation, leading to issues such as drafts and moisture infiltration. Therefore, ensuring a loose fit within the rough opening is essential for optimal functionality and durability of the window over its lifespan.