The short answer
What Causes the Leak
When snow sits on your roof, it acts like a blanket. Heat from your home rises into the attic, warms the roof deck, and melts the snow from underneath. That meltwater runs down the roof until it hits a colder edge, often the eaves or a valley, where it refreezes into an ice dam.
The ice dam blocks the water from draining. Water then pools behind it and finds the path of least resistance, which is often under shingles, around flashing, or through a nail hole. That is why the leak happens only during a thaw, not while the snow is still frozen.
- Ice dams form at eaves and valleys
- Trapped water backs up under roofing
- Flashing seams and nail holes are common entry points
- Attic heat accelerates the melting
- Cold outdoor air refreezes the runoff
- The leak may appear hours after melting starts
Check Your Attic First
Before blaming the roof itself, look in your attic. You need to see where the warm air is escaping. Gaps around vents, recessed lights, or an unsealed attic hatch let heat reach the underside of the roof deck. That heat is what fuels the melting.
Look for dark stains or damp spots on the underside of the roof sheathing. Those marks show where water has been tracking. Also check the insulation; if it is compressed or missing, heat moves through easily. Fixing these issues often reduces or stops the melting.
What You Can Do Yourself
You can take some steps right away. Use a roof rake to pull off snow from the edge, but avoid scraping the shingles. Never try to chip ice with a shovel or an ax, because that can tear the roofing material. Working from a ladder is risky, so stay safe and consider hiring a pro.
Inside the house, seal any air leaks with caulk or weatherstripping. Add insulation if yours is thin, and make sure the attic is well ventilated. These changes keep the roof deck cold, so snow melts evenly and less water backs up under the shingles.
When to Call the Pros
If the leak is already staining your ceiling or walls, you need more than snow removal. The pros can locate the exact entry point, often by tracing the water path from inside. They may use moisture meters to find hidden damp spots in the roof structure.
Roof work is dangerous, especially on a slippery, snow-covered surface. The pros have the right ladders, safety gear, and experience to work on a roof in winter. They can also check the flashing, vents, and pipe boots that might be the source of the leak.
Cost and Repair Realities
Fixing a snow melt leak can range widely in cost. A simple air-sealing project might cost a few hundred dollars, while replacing a section of roof or repairing rotted sheathing can run into the thousands. The total depends on the extent of the damage and the materials involved.
The final price also depends on the condition of your roof, the pitch, and how easy it is to access. If the leak is from an ice dam, the repair might be minor. But if water has soaked the insulation or rotted the wood, the work becomes larger. Always get a detailed inspection before deciding on a fix.
Talk to someone now
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (425) 407-5186Frequently asked questions
Will the leak stop when the snow is gone?
Not necessarily. Once the snow melts, the ice dam disappears, so the immediate leak may stop. But the water that already entered can cause ongoing damage, like mold or rot. You need to dry the area and fix the underlying cause.
Can I just ignore it until spring?
Ignoring it allows water to soak into insulation, drywall, and wood, leading to mold and structural decay. The longer it sits, the more extensive the repair. Acting quickly, even just to stop the flow and dry the area, is wise.
Should I remove all the snow from my roof?
Removing snow can help, but only the bottom few feet matter for ice dams. Clearing the entire roof is unnecessary and risky. Use a roof rake from the ground or hire a pro. Focus on the edge to let meltwater escape.