For cold climates, an ice-and-water barrier should extend inside the wall line by how much?

In cold climates, an ice-and-water barrier plays a crucial role in preventing water infiltration and ice dam formation, which can cause significant structural damage. The recommended practice is for this barrier to extend inside the wall line by a minimum of 2 feet. This extension provides an extra layer of protection against wind-driven rain and melting snow, which can easily seep into the building envelope and lead to leaks or mold growth.

Extending the barrier this far ensures that any water that may enter around the eaves and down into the wall can be effectively managed before it reaches the vulnerable parts of the wall system. By adhering to this guideline, builders can help maintain the integrity and longevity of roofing structures, particularly in regions that experience heavy snowfall and freezing temperatures. This precautionary measure illustrates an understanding of how weather-related challenges can impact building design and materials.