What additional protection should be provided in valleys besides normal felt or tar paper?

In roofing, valleys are critical areas that direct water flow from the roof slope, and they often experience higher concentrations of water runoff. This makes them susceptible to leaks and water damage if not properly protected. While normal felt or tar paper provides some level of waterproofing, additional protection is recommended for valleys to ensure adequate defense against potential leaks.

Using an ice and water shield is particularly effective because it is a self-adhering membrane that creates a watertight barrier, even under low-temperature conditions where ice or snow may be present. This layer enhances the waterproofing capabilities, especially in climates where ice damming can occur.

Additionally, the mention of roofing felt and roll roofing indicates that multiple types of materials can provide further protection. Having a 36-inch layer of roofing felt or roll roofing applied in conjunction with the ice and water shield helps create a comprehensive shield against water penetration.

The inclusion of all these options suggests that utilizing multiple types of protection in the valley increases overall durability and resilience against water infiltration. Therefore, the combination of these materials—each serving a unique purpose—ensures that the roofing system is fortified against the vulnerabilities associated with valleys.