Ice dam risk in Ashtabula, OH
Will your roof get ice dams in Ashtabula, OH?
20.3 dam days a winter
High risk. On an ordinary house in Ashtabula, conditions for an ice dam come on about 20.3 days in a normal winter, mostly in January and February.
Ashtabula averages 90 inches of snow a year and about 67 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 Ashtabula
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 10.4 | Moderate |
| Typical, some insulation, not air-sealed | 20.3 | High |
| Older or poorly insulated, warm attic | 32.6 | High |
Sealing and insulating a typical attic takes out about 9.9 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 32.6 days.
What to do about ice dams in Ashtabula
- 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.
Ashtabula winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 29.6 | 21.0 | 7.5 |
| February | 15.8 | 17.2 | 5.7 |
| March | 12.5 | 9.8 | 2.3 |
| April | 2.4 | 1.1 | 0.1 |
| October | 0.4 | 0.2 | 0.0 |
| November | 8.4 | 4.0 | 0.6 |
| December | 20.8 | 13.8 | 4.0 |
Ashtabula next to nearby towns
Ashtabula ranks 16 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.
- Conneaut, OH 12 mi, 24.2 days
- Painesville, OH 26 mi, 24.8 days
- Mentor, OH 31 mi, 24.8 days
- Willoughby, OH 36 mi, 24.8 days
- Eastlake, OH 36 mi, 24.8 days
Where these numbers come from
NOAA 1991–2020 climate normals from Dorset, 15.2 miles from Ashtabula. 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.