đ§ Ice & Water Shield Calculator
Calculate ice and water shield membrane needed for eaves, valleys, and penetrations. Based on climate zone requirements.
How to Use This Calculator
Enter the total length of all eaves, the combined length of all valleys, and the number of roof penetrations (vents, chimneys, skylights). Set your overhang depth and select your climate zone based on your geographic location.
Understanding Your Results
Ice and water shield coverage at eaves extends from the edge to at least 24 inches past the interior wall line. Colder climate zones may require wider coverage. Valley coverage uses a 3-foot-wide strip. Each penetration gets a minimum 3x3 foot application around the opening.
Frequently Asked Questions
How much ice and water shield do I need?
Code typically requires ice shield from the eave edge to at least 24 inches inside the exterior wall line. For a 12-inch overhang, that means about 3 feet up from the eave. Add coverage for all valleys and around penetrations.
Do I need ice and water shield?
In climate zones with average January temperatures of 25°F or below, ice and water shield is required by code at eaves. It's also required in valleys and around penetrations (chimneys, vents, skylights) in most jurisdictions.
How wide is ice and water shield?
Standard ice and water shield rolls are 36 inches (3 feet) wide and 66.7 feet long, covering about 200 sq ft per roll (2 squares). Some manufacturers offer narrower rolls for specific applications.