What is meant by "Nesting" in roofing applications?

Nesting in roofing applications refers to the process of installing new roofing materials directly over existing roofing layers. This method can be attractive for its convenience, as it eliminates the need for complete tear-off and removal of old materials, saving time and labor costs. Nesting can create a thicker roof which might provide additional insulation benefits and help in improving some roof characteristics. However, it's important to ensure that the underlying roof is in suitable condition to support the new layer and that local building codes allow for such practices.

The other options describe different aspects of roofing but do not define nesting. For instance, the removal of old roofing materials is a separate procedure necessary in certain situations, while methods aimed at enhancing drainage or improving insulation performance do not align with the concept of nesting itself. Each of those processes serves its own distinct purpose within overall roofing practices.