Roofing Code Requirements in Wisconsin

Northern Wisconsin (Zone 7): Douglas, Bayfield, Ashland, Iron, Vilas, Oneida, Forest, Florence, Price, Sawyer, Washburn, Burnett, Rusk, Lincoln, Langlade, Taylor, Clark counties. Northern Wisconsin experiences some of coldest temperatures in contiguous US. Frost depth can exceed 5 feet in severe winters. Extra insulation and frost protection measures recommended beyond code minimums.

Northern Wisconsin (Zone 7) and areas with lake-effect snow: Bayfield, Ashland, Iron, Douglas, Vilas, Oneida counties; Lake Michigan snow belt in Door, Kewaunee, Manitowoc counties. Northern Wisconsin and lake-effect snow belts experience heavy snow loads. Verify site-specific snow load requirements. Higher than standard loads may apply in elevated areas.

Mississippi River corridor (western border), Wisconsin River, Fox River, Rock River, Lake Michigan/Superior shorelines, numerous inland waterways. Wisconsin has extensive flood risk along major rivers and lake shorelines. Great Lakes coastal flooding also a concern. Verify FEMA maps and local floodplain requirements. Wisconsin DNR provides floodplain management.

Lake Michigan shoreline counties: Kenosha, Racine, Milwaukee, Ozaukee, Sheboygan, Manitowoc, Kewaunee, Door (eastern shore). Lake Michigan water levels fluctuate significantly (several feet over decades). Shoreline erosion is ongoing concern. Bluff areas may have stability issues. Verify setback requirements with local jurisdiction.

Lake Superior shoreline counties: Douglas (Superior), Bayfield, Ashland, Iron (Hurley area). Lake Superior shoreline experiences extreme winter conditions. Lake-effect snow can be significant. Coldest part of Wisconsin. Higher insulation and frost protection recommended.

Southern and western Wisconsin counties with highest radon potential: Dane, Rock, Green, Lafayette, Iowa, Grant, Crawford, Vernon, Richland, Sauk, Columbia, Dodge, Jefferson, Walworth counties. Wisconsin has elevated radon risk in many areas. Testing recommended for all homes. RRNC adds minimal cost to new construction (~$500-1000). Wisconsin Department of Health Services provides radon testing resources.

State with significant severe hail frequency per NOAA SPC storm reports. Insurance restoration contractors should document pre-existing hail damage and recommend impact-resistant materials.

Ice barrier underlayment is REQUIRED statewide per Wisconsin Uniform Dwelling Code (IRC R905.1.2). Wisconsin spans Climate Zones 6A (southern) and 7 (northern). Mean January temperatures range from 22°F (Milwaukee) to 10°F (northern Wisconsin). Heavy snowfall (40-80+ inches/year statewide, 100+ in northern counties).

State within or adjacent to the tornado corridor. NOAA SPC data confirms significant tornado frequency. Enhanced structural requirements apply per IRC R301.2.1.2.