Ice Dams on Candlewood Lake Homes: Why They Form and What Stops Them

What actually causes an ice dam?

Heat from the living space leaks into the attic and warms the underside of the roof deck. Snow melts there, and the water runs down to the unheated overhang, where it freezes again. Repeated over days, the frozen edge builds into a ridge that traps later meltwater and forces it under the shingles.

The key is a temperature difference across the roof. A properly insulated, ventilated attic keeps the roof deck near the outdoor temperature, so snow melts only when the weather warms. A leaky attic warms the deck from below, so snow melts in the middle of the roof while the eaves, which have no heated space beneath them, stay frozen.

Outside weather sets the stage. Roughly 45 inches of snow falls in a typical winter in the Danbury area, by most estimates, and the snow season runs from late October to mid-April. January is the snowiest month. Cold snaps followed by thaws give the cycle of melt and refreeze that builds a dam.

So ice dams are a house problem showing up as a roof problem. Where the same eave grows ice every winter, the attic beneath it is almost always leaking heat.

Why are converted lake cottages the usual suspects?

Many Candlewood Lake cottages were built as seasonal homes with light insulation and wall cavities that open into the attic. When owners began living in them all winter, heat went up and the roofs started melting snow from below. Their attics were never designed for it, and later additions made airflow worse.

Typical features include shallow or vaulted ceilings, knee-walls without baffles, recessed lights cut into the ceiling, bath fans that vent into the attic and chimney chases that carry warm air straight up. Each is a path for heat.

Housing here is mixed: older farmhouses on large lots and lake homes from the mid-century onward, with communities such as Candlewood Lake Estates and Deer Run Shores. The houses most at risk are those whose use changed after they were built.

The service page on attic insulation and ventilation goes through how a contractor assesses this kind of house.

What do the signs of an ice dam look like?

Look for a thick ridge of ice along the eave, long icicles, snow that has melted off the upper roof while the edge stays frozen, and brown stains on ceilings or exterior walls during a thaw. Uneven icicles on one side of the house often show where heat is escaping.

The table pairs what you see with what it usually means. It is a guide to describing the problem on the phone, not a diagnosis.

How does a roofer remove an ice dam?

A roofer typically cuts drainage channels through the ice using controlled low-pressure steam or careful hand work, so meltwater can run off. The aim is to relieve the leak without damaging shingles. Chopping with axes or hammers tears shingles and flashing, and is a common cause of new leaks.

This is a winter job, done on cold, often icy roofs, so the roofer decides whether it is safe. In bad conditions, the answer may be to contain the water inside and wait.

Calcium chloride or other de-icing products can be used in some situations, but they can stain, corrode or harm plants, so ask what the roofer proposes. The service page on ice dam removal and prevention covers the steps in detail.

If water is entering now, the first priority is stopping it, and the page on emergency roof leak repair explains what happens.

What stops them coming back?

Seal the air leaks between the living space and the attic, bring insulation up to a level suited to a cold climate, and give the roof deck a clear path of air from the soffits to the ridge. Together these keep the deck cold so snow melts evenly instead of at the eaves.

Air sealing comes first. Gaps around recessed lights, wiring and plumbing, the attic hatch and chimney chases are the usual sources. Insulation laid over open gaps hides them without stopping the air.

Guidance for cold climates often cites attic insulation in the range of R-49 to R-60, though the right level depends on the house and what is there. Ask the contractor to measure and explain.

Ventilation completes the system. Soffit vents bring air in at the eave and a ridge vent lets it out at the peak, with baffles keeping insulation from blocking the intake.

• Seal air leaks at lights, ducts, hatch and chimney chase
• Add insulation to a depth suited to a cold climate
• Install baffles so insulation does not block the soffits
• Keep soffit and ridge ventilation balanced

Does an ice barrier or a new roof prevent ice dams?

No. An ice barrier, a self-adhering membrane under the shingles at the eaves, limits leaks when a dam forms, but it does not stop one forming. A new roof without attic work will probably grow the same dams. The membrane is damage control and the attic is the cure.

Still, the membrane is worth having. It seals around nails and gives backed-up water less chance of reaching the decking. A roofer can add it when the roof is replaced.

Heat cables along the eave can keep a channel open. They use electricity and can fail, and they do not address the cause. They are a patch for a spot you cannot fix any other way.

What can I do myself, safely?

From the ground, use a roof rake with a long handle to pull snow off the first few feet of the eave before it melts. Keep gutters and downspouts clear in autumn, and check the attic for frost and damp. Do not climb onto an icy roof or chop at the ice.

Stay out from under the load while raking, and never use a ladder in snow. A rake pulls snow off in slabs that can fall hard.

Photograph ice, stains and the attic. Notes on when it happened help the roofer. See gutter repair for the roof edge.

How does the winter calendar around Sherman set the stage?

Snow season runs from late October to mid-April, with January the snowiest month at roughly 11 inches in the Danbury area. Ice dams peak when cold snaps are followed by thaws, which in this region can happen several times a winter. The risk is highest after a big snowfall that sits for days.

A single heavy storm is not the worst case. A week of cold that leaves snow on the roof, followed by a sunny day above freezing, is the classic setup. The upper roof warms, melts and sends water downhill to an edge that is still frozen.

Wooded lots complicate the picture. Shade keeps north slopes cold, so snow lingers where sun cannot reach, and tall trees drop limbs and leaves that clog gutters before winter even begins. A gutter full of frozen leaves is a ready-made dam.

It is worth walking the house after the first big snowfall and again after the first thaw, from the ground. Note where the snow has gone and where it has not. Those notes tell a roofer more than a general description will.

What should I tell the roofer when I call?

Say which town you are in, which eaves have ice, whether water is coming in, how long the ice has been there and how the house is reached. Mention the age of the house and any past attic work. These details let the roofer decide how urgent it is and what to bring.

Photographs help. A shot of the eave from the ground, the ceiling stain and the attic hatch with its insulation tell the story quickly. If you can safely see into the attic, note frost on the nails or damp insulation near the eaves.

Say plainly whether it is a leak or only ice. A leak moves the job to the top of the list, but the roofer decides when a crew can come and whether it is safe. No arrival time is promised by this line, which answers at any hour.

Ask what the visit will include, whether the roofer will look at the attic, and how the lasting fix will be quoted. Removing ice and fixing the attic are separate jobs and should be priced separately.