Do gutters prevent ice dams?
Gutters do not prevent ice dams on their own. They drain the meltwater a dam would otherwise hold back, and they work best alongside the insulation and ventilation that keep the roof cold.
The cause of an ice dam is heat escaping from the living space into the attic. That heat melts snow on the roof, and the water runs to the eave, which is outside the warm part of the house and therefore cold. The water refreezes there and builds a ridge that holds back more meltwater. A clear gutter removes the water that reaches the gutter line, but it does not stop the melt upstream.
Why do gutters fail, and what does a technician check?
Gutters usually fail at their joints, hangers and outlets. A technician checks the pitch, the fasteners, the fascia and the downspouts together.
Sagging runs are the first sign. A gutter that holds standing water has lost its pitch, usually because hangers have pulled out of the fascia or because ice has stretched the run. Joints that leak drip onto the fascia and rot the wood behind it. Downspouts that are blocked, or too few for the roof area, send water over the edge at the corners, where it does the most harm.
Leaves and needles are the other common cause. Gutters on tree-covered lots can fill every autumn, and a wet mat of debris at the outlet stops water flowing even when the gutter itself is sound. The technician checks any gutter guards and whether they block the outlets rather than the water, since a guard that holds leaves on top can trap debris below it.
Should a gutter be repaired or replaced?
A sound gutter with a few sagging hangers or a leaking joint can be repaired. A run that is bent, rotted at the fascia or wrong in pitch is usually better replaced.
Repair suits a run that is mostly sound. Hangers are reset, a joint is re-seamed, a short section is re-pitched and the outlets are cleared. The fascia behind the gutter must be checked for rot at the same time, because a repaired gutter fixed to soft wood will not hold.
Replacement suits a gutter that has been dented, crushed by ice or corroded through, or where metals have been mixed in ways that cause galvanic corrosion. The National Park Service guidance says to use one metal type for flashings and gutters, and to keep heavier copper in gutters and valleys where it is used. The choice of metal is part of the replacement, not an afterthought.
What affects the cost of gutter work?
Cost depends on the length of the run, the height of the eave, the number and placement of downspouts, the condition of the fascia and the metal chosen. The price is explained and approved before work starts.
Length and height are the first drivers. A short run over a single-story ell is a different job from a full perimeter on a three-decker, where the eave sits high and the crew needs a boom or staging to reach it. Each downspout, outlet and corner also adds fitting time, and each change of direction in the run is a joint that has to be made right.
What can a homeowner do before winter?
Clear the gutters and downspouts, confirm that water leaves the house, and note any sagging or staining at the fascia. Do the cleaning from the ground or from a stable ladder, not from a snow-covered roof.
Look for water spilling over the front of the gutter during a rain, and for drips at the joints. Note any hanger that has pulled out and any staining on the fascia below. A gutter that overflows at a single point usually has a blocked outlet or a low section that needs attention.
Check that each downspout discharges well away from the foundation and is not blocked at the bottom. Ice build-up in winter is a sign that water is pooling at the eave. Note where and when it appears, so the technician can look at the roof edge first when the time comes.