Ice dam risk in Gahanna, OH
Will your roof get ice dams in Gahanna, OH?
6.7 dam days a winter
Moderate risk. On an ordinary house in Gahanna, conditions for an ice dam come on about 6.7 days in a normal winter, mostly in January and February.
Gahanna averages 28 inches of snow a year and about 27 days with snow on the ground. Most of it comes and goes within a few days. 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 Gahanna
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 3.8 | Low |
| Typical, some insulation, not air-sealed | 6.7 | Moderate |
| Older or poorly insulated, warm attic | 10.2 | Moderate |
Sealing and insulating a typical attic takes out about 2.8 days a winter here. It drops the risk from moderate to low. An older house with a warm attic should expect closer to 10.2 days.
What to do about ice dams in Gahanna
- 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.
Which to spend on first: air sealing or heat cable.
Gahanna winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 9.5 | 10.7 | 3.1 |
| February | 7.6 | 7.5 | 2.0 |
| March | 4.1 | 2.5 | 0.4 |
| April | 0.5 | 0.1 | 0.0 |
| October | 0.2 | 0.0 | 0.0 |
| November | 1.2 | 0.6 | 0.1 |
| December | 5.1 | 5.1 | 1.2 |
Gahanna next to nearby towns
Gahanna ranks 139 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.
- Whitehall, OH 5 mi, 6.7 days
- Bexley, OH 6 mi, 6.7 days
- Westerville, OH 6 mi, 6.6 days
- New Albany, OH 7 mi, 6.7 days
- Columbus, OH 7 mi, 6.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from John Glenn International Airport, 3.2 miles from Gahanna. 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.