What can happen if sheathing is fitted too closely together?

When sheathing is fitted too closely together, it can lead to moisture damage. This occurs because wood sheathing, typically made from materials like plywood or OSB (oriented strand board), needs a certain amount of space for expansion and contraction due to changes in temperature and humidity. If the sheathing is installed too tightly, it may not have the room to expand, leading to buckling or warping over time. This can create gaps where moisture can penetrate, which can result in rot, mold, and other forms of structural damage. Proper spacing allows for movement and helps maintain the integrity of the sheathing, safeguarding against moisture-related issues in the building envelope.

The other choices do not accurately reflect the consequences of tightly fitted sheathing. Enhanced structural integrity is not a result of close fitting; in fact, it can compromise the roof’s overall stability. Similarly, air circulation cannot be effectively prevented solely by sheathing fit, as other factors in the roofing system influence airflow. Lastly, the weight on the roof from sheathing does not correlate with the fitting of the panels; sheathing primarily contributes to the structural support and its weight is constant regardless of how tightly the pieces are joined together.