Ice Dams: Fall Gutter, Roof and Attic Prep to Prevent Winter Roof Leaks
Published
What causes ice dams, the fall checklist that helps prevent them (gutters, roof, attic air sealing and insulation), what to do safely if one forms, and how insurance generally treats ice dam water damage.
What causes ice dams?
Short answer: An ice dam is a ridge of ice at the edge of a roof that stops melting snow from draining off. The University of Minnesota Extension explains that it forms when there is snow on the roof, the upper roof surface is above freezing and the lower edge is below freezing. Snow melts on the warm part of the roof, runs down and refreezes at the cold eaves. The heat comes mainly from the house, and in many homes warm air leaking into the attic is the biggest cause.
Will cleaning my gutters prevent ice dams?
Short answer: Clean gutters help, but they don't fix the root cause. Connecticut's Insurance Department notes that water that can't drain off the roof can freeze and add to ice dams, so clear gutters and downspouts in the fall. The lasting fix is keeping the roof evenly cold: seal air leaks from the living space into the attic first, then add insulation (University of Minnesota Extension).
Does homeowners insurance cover ice dam damage?
Short answer: Often, but it depends on your policy. The Massachusetts Division of Insurance says damage to the exterior and interior of a home from ice dams is generally covered under a homeowners policy, but only the area damaged in the loss, and damage from wear and tear or neglect is not. Policies and state rules differ, so check your own policy or ask your agent. Only your insurer decides coverage.
How an ice dam causes a leak
According to the University of Minnesota Extension, the water that backs up behind an ice dam stays liquid, finds cracks and openings in the roof covering, and flows into the attic. From there it can run into exterior walls or through the ceiling insulation and stain the ceiling. Moisture that gets into the house this way can also lead to mold and mildew if it isn't dried quickly.
Fall checklist: gutters and downspouts
Before the first snow, clean gutters, downspouts and drains of leaves, tree debris and anything else that restricts flow, and make sure the gutters are firmly secured to the house. Check that downspouts carry water at least 3 to 4 feet away from the foundation (Connecticut Insurance Department). FEMA's winter storm guide also says to clear rain gutters and cut away tree branches that could fall on the house. If you can't reach the gutters safely from a ladder on firm, level ground, hire a pro.
Fall checklist: the roof
Inspect the roof, secure loose shingles and repair leaks before winter, and check and repair flashing around roof edges, vent stacks, skylights and chimneys (Connecticut Insurance Department). FEMA recommends repairing roof leaks and having a contractor check that the roof can handle the extra weight of snow and ice. A fall inspection is also a good time to catch damage from summer and fall storms, such as lifted or missing shingles, before winter weather makes it worse.
The real fix: air sealing and insulation
The Building America Solution Center (PNNL, for the U.S. Department of Energy) lists three steps: fully air seal the ceiling, thoroughly insulate the attic, and ventilate the roof. Air sealing comes first. Common leaks into the attic include gaps around wiring, light fixtures (especially recessed can lights), plumbing stacks, furnace flues and chimneys, attic hatches and stairs, and exhaust fan housings. In a vented attic, baffles should keep insulation out of the soffit vents and leave an air gap between the insulation and the roof deck. The University of Minnesota Extension adds that bathroom and kitchen exhausts should vent outside rather than into the attic area, and that powered attic fans are not a recommended fix because they can create other moisture problems. A weatherization or energy professional can use a blower door test and an infrared camera to find where heat is escaping.
If an ice dam forms
Stay off an icy roof. The University of Minnesota Extension warns that anyone working on or below a roof in winter risks injury and can damage the roof, and recommends professionals for this work. From the ground, a roof rake can pull snow off the lower roof, though it may damage roofing. If water is actively coming in, a pro can cut channels through the dam so water can drain; the Extension notes this is only a temporary fix.
If water is coming inside
Move belongings away from the leak, catch dripping water, and keep people away from wet ceilings that are sagging or near light fixtures and outlets. Take photos and video of the ice dam, the roof edge and every wet area inside before anything is moved or thrown out, and contact your insurer or agent promptly. EPA says to dry water-damaged areas and items within 24 to 48 hours to help prevent mold. The University of Minnesota Extension says not to repair interior damage until ceilings and walls are dry, and to fix the heat loss at the same time so the damage doesn't come back.
Insurance: what to know
Coverage depends on your policy. The Massachusetts Division of Insurance says ice dam damage to the exterior and interior is generally covered, but only the damaged area, and damage from wear and tear or neglect is not. Read your policy, ask your agent if you're unsure, and keep your photos, receipts and notes together.
How we can help
ClaimToRepair makes the insurance side easier and gets the repairs done. One licensed local roofing or water damage pro can do a free inspection, document the damage with photos and an estimate you can share with your adjuster, and quote the repair and drying. We don't file, negotiate or adjust claims, and only your insurer decides what is covered. If water is coming through the ceiling right now, use Get immediate help: the same-day option has a $50 dispatch fee that is refunded if no one arrives the same day and isn't applied to the cost of the job, or you can schedule a visit instead.
Sources
- University of Minnesota Extension: Dealing with and preventing ice dams
- U.S. DOE Building America Solution Center (PNNL): Attic Air Sealing, Insulating, and Ventilating for Ice Dam Prevention
- Connecticut Insurance Department: Winter Ready, Prepare Your Home (PDF)
- FEMA / Ready.gov: How to Prepare for a Winter Storm (PDF)
- Massachusetts Division of Insurance: Frequently Asked Questions about Homeowners Insurance
- U.S. EPA: A Brief Guide to Mold, Moisture and Your Home
General information only, not legal or insurance advice. Coverage depends on your policy.