Ice dam risk in Erie, PA
Will your roof get ice dams in Erie, PA?
17.1 dam days a winter
High risk. On an ordinary house in Erie, conditions for an ice dam come on about 17.1 days in a normal winter, mostly in January and February.
Erie averages 104 inches of snow a year and about 63 days with snow on the ground. Snow that lies that long is what turns a little attic heat into a ridge of ice at the eave. The conditions that make a dam need all three at once: snow, cold at the eave and heat above it.
What your attic does to that number in Erie
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 8.6 | Moderate |
| Typical, some insulation, not air-sealed | 17.1 | High |
| Older or poorly insulated, warm attic | 27.8 | High |
Sealing and insulating a typical attic takes out about 8.5 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 27.8 days.
Preventing ice dams on a Erie roof
- Air-seal the attic floor: the gaps around the hatch, light fixtures, plumbing stacks and the top plates of interior walls. This is the fix that removes the cause, and it usually costs less than a season of contractor ice removal.
- Rake the bottom three or four feet of roof after any storm that leaves more than about six inches, from the ground with a roof rake.
- At the next reroof, ask for ice-and-water membrane under the shingles from the eave to at least 24 inches inside the wall line. It does not stop a dam; it stops the leak when one forms.
Which to spend on first: air sealing or heat cable.
Erie winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 31.8 | 19.8 | 6.5 |
| February | 19.4 | 16.8 | 5.3 |
| March | 14.5 | 9.1 | 2.0 |
| April | 2.6 | 1.0 | 0.1 |
| October | 0.1 | 0.0 | 0.0 |
| November | 9.6 | 4.5 | 0.4 |
| December | 26.3 | 11.8 | 2.8 |
Erie next to nearby towns
Erie ranks 8 of 68 Pennsylvania cities here for ice-dam days, behind St. Marys at 26.9 days.
- Conneaut, OH 29 mi, 24.2 days
- Meadville, PA 33 mi, 19.8 days
- Ashtabula, OH 41 mi, 20.3 days
- Jamestown, NY 43 mi, 25.4 days
- Dunkirk, NY 45 mi, 25.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Erie International Airport, 6.1 miles from Erie. A dam day is a day with snow on the roof and freezing at the eave while heat or sun melts the snow above it. This describes a normal winter, not this one.