General Exterior Code Requirements in Maine

Ground snow loads range from 40 psf along the southern coast to 100+ psf in northern Aroostook County and western mountains (Franklin, Oxford, Somerset counties). Most of the state exceeds 60 psf. Northern interior commonly 80-100 psf. Annual snowfall averages 60-90 inches statewide, with 100+ inches in mountains. Many locations exceed IRC prescriptive table limits and require engineered roof framing.

Maine has numerous National Register Historic Districts and individually listed historic properties. Major districts include: Portland Old Port Historic District (Cumberland County), Kennebunkport Historic District (York County), Bath Historic District (Sagadahoc County), Camden Historic District (Knox County), Castine Historic District (Hancock County), Wiscasset Historic District (Lincoln County), Belfast Historic District (Waldo County), Hallowell Historic District (Kennebec County), and many others. Maine Historical Preservation Commission oversees review process.

Northern and mountainous Maine experiences extreme snow loads (80-120+ psf ground snow load) and high wind exposure. Aroostook County, Piscataquis County, and mountainous areas of Franklin, Oxford, and Somerset counties have the highest snow loads in the eastern US. Coastal areas experience high winds from nor'easters (90-130 mph gusts). Mt. Washington region influence extends into western Maine mountains.

Coastal high hazard areas (V-zones and VE-zones) along Maine's approximately 3,478-mile Atlantic coastline (including islands). Subject to wave action, storm surge, and velocity flooding. Affects coastal portions of York, Cumberland, Sagadahoc, Lincoln, Knox, Waldo, Hancock, and Washington counties. Maine is exposed to powerful nor'easters that can produce hurricane-force winds and significant storm surge. Climate change is increasing coastal flood risk.

Areas designated as Zone A, AE, V, or VE on FEMA Flood Insurance Rate Maps. Maine has significant flood risk along major rivers: Penobscot River (Penobscot County), Kennebec River (Kennebec/Sagadahoc counties), Androscoggin River (Androscoggin/Sagadahoc counties), Saco River (York County), and numerous coastal areas. Spring snowmelt flooding is a major concern due to heavy snowpack. Atlantic coastal flooding from nor'easters and storm surge affects all coastal counties.

Ice barrier underlayment is REQUIRED statewide on all roof eaves per IRC R905.1.2. Mean January temperature is well below 25°F throughout the entire state. Heavy snowfall (60-90+ inches/year) and freeze-thaw cycles create severe ice dam conditions. Extended coverage beyond the minimum 24 inches inside exterior wall line is strongly recommended in northern and mountain areas.

Coastal and southern Maine within ASCE 7 hurricane-prone region. Exposed to post-tropical cyclones and nor'easters.