Gutters here spend part of every winter full of ice. This page covers what that does to them, how to size downspouts, the profiles old houses wear, where the water may go near a lake, and what heat cable can and cannot do.
A gutter's summer job is simple: catch the water off the eave and put it somewhere other than the foundation. In southern Maine it has a winter job too, and that one is harder. It fills with snow and ice, it sits right where ice dams form, and on a metal or steep slate roof it is in the path of snow sliding off.
What the town, the shoreland rules, a historic district or the house itself asks of a gutter varies from place to place, and so does how well a given gutter survives February. This page covers ice and gutters, sizing, materials and historic profiles, hanging them to take winter loads, where the water goes, heat cable, and a fall checklist.
University of Minnesota Extension defines an ice dam as a ridge of ice that forms at the edge of a roof and keeps melting snow from draining off. The cause is heat: snow melts on a roof warmed from below, and the water freezes again over the cold eave. A gutter is not what starts the dam, and taking gutters down does not stop dams on a house that leaks heat into its attic.
What a gutter does do is give the ice somewhere to collect. A trough packed solid with ice is heavy, pulls on its hangers, and holds meltwater against the roof edge and the fascia board. The Maine Emergency Management Agency asks owners to keep gutters and drains clean and free of ice and snow, and to keep downspouts clear where they meet the ground, so meltwater has a way out.
Kennebunk's historic district guidelines give a simple rule for downspouts, based on the area of roof that drains to each one:
Their size and spacing, the guidelines add, follow the area and pitch of the roof. A steep roof sheds water faster than its footprint suggests, and a long run of gutter on a big eave may need a downspout at each end.
The gutter itself has to be big enough for the downspouts it feeds and pitched toward them. Common residential sizes are 5 and 6 inches across the top; the larger size carries more water and is less likely to overflow when a thaw dumps a roof's worth of meltwater at once. A written quote should name the gutter size, its metal and thickness, the downspout size and how many there are.
Kennebunk's guidelines describe what old houses in its historic district wear: metal gutters in half-round or ogee shapes, made of galvanized steel, copper, lead-coated copper or aluminum, often with round downspouts on half-round gutters. A few houses still have built-in gutters, lined troughs set into the cornice so the system hardly shows.
The guidelines ask for historic gutters to be kept and repaired with matching material, and do not recommend swapping a built-in gutter for a hung one. A new gutter should match the old one's color, size and shape; gutters formed on site in one piece can be made to match an original profile.
Built-in gutters deserve a careful look on any old house: a failed lining sends water straight into the cornice and the wall below, out of sight.
A gutter full of ice weighs far more than one full of rain; the emergency management agency puts a cubic foot of ice at about 62 pounds. The hangers carry that, so how they attach matters:
On a metal roof or a steep slate roof, snow sliding off in a sheet can take a gutter with it. That is a reason to plan snow retention on the roof, or to leave a gutter off a slope where the snow will always win; see metal roofing.
A downspout that dumps beside the foundation undoes most of the gutter's work. Carry the water away from the house, toward ground that slopes off, and not across a walk or driveway where it will freeze.
Near water, towns have rules of their own:
Gutters on their own rarely need a permit, but a project that adds roof or changes a building near a lake or the shore brings the runoff into the review. The town page for each town lists its shoreland and flood permits where the research found them.
Efficiency Maine's ice-dam advice covers the options in one breath: raking the roof can help but is hard work and easy to miss a storm with; electric heat tape can prevent ice dams but can be expensive to run; and weatherizing the house can end ice dams while cutting energy bills.
Heat cable in a gutter and downspout keeps a channel open so meltwater can get off the roof. It does nothing about the heat leaking into the attic that is melting the snow, and it uses electricity every hour it runs. On a house with one stubborn spot, such as a valley over an entry, it can be a reasonable stopgap while the attic gets fixed.
What not to do comes from the emergency management agency: no hair dryers, heat guns or open flames on roof or gutter ice. An open flame can damage roofs and gutters and set a house on fire. University of Minnesota Extension describes a temporary fix for a dam that is leaking now: on a mild day, cut a channel through it with tap water from a hose, starting at the lower edge.
Gutters are usually best replaced with the roof, when the drip edge and the gutter can be fitted together. A roof inspection covers the gutters too; see roof inspection.
No. University of Minnesota Extension explains that ice dams come from heat warming the upper roof so snow melts and refreezes at the cold edge. A gutter gives the ice a place to collect and can be pulled down by its weight, but the fix for the dam is air sealing and insulation in the attic.
Kennebunk's historic guidelines use a rule of one inch of downspout diameter for each 100 square feet of roof, so a three-inch downspout drains about 300 square feet, with downspouts no more than 40 feet apart. Steep roofs and long eaves may need more.
Sometimes, as a stopgap. Efficiency Maine says electric heat tape can prevent ice dams but can be expensive to operate. It keeps a channel open for meltwater; it does not stop the heat loss that causes the dam, which weatherizing the attic does.
That varies by town. York's Historic District Commission guidelines say aluminum gutters should not be used in its districts, and Portland requires preservation approval for visible gutter work on a designated property. Kennebunk's guidelines ask for replacements that match the original in color, size and shape.
Usually not on their own. Near lakes and the shore, though, towns review roof runoff when a building is added to or changed: Bridgton, for example, wants runoff from new or enlarged roof areas in its shoreland zone sent to a drip-edge collection system that can hold a 2-inch, 24-hour rain.
Gutters across greater Portland and southern Maine, from Casco Bay and the York County coast to the Sebago Lake towns. Each city has its own page with the permit rule and code edition that apply there:
Sources: University of Minnesota Extension, Dealing with and preventing ice dams · Maine Emergency Management Agency, severe winter storms (gutters, roof rakes, ice) · Efficiency Maine, Insulation (ice dams, heat tape) · Town of Kennebunk, historic district design guidelines: chimneys, drainage and roof components · Town of York, Historic District Commission guidelines (gutters) · City of Portland, historic preservation review · MUBEC residential code (2021 IRC with Maine amendments), R905.2.8.5 drip edge (UpCodes copy) · Town of Bridgton, Land Use Code (shoreland roof runoff) · Town of Cumberland, Code Enforcement (shoreland zoning permit) · Town of Yarmouth, solar permitting checklist (shoreland overlay) · City of Westbrook, Code Enforcement. Codes, programs and prices change; confirm the current rule with your city before you rely on it.
Free inspection, a written scope, and photos you keep either way.
Book my free inspection →
