Ice dam risk in Tooele, UT
Ice dams in Tooele, UT: how often
16.4 dam days a winter
High risk. On an ordinary house in Tooele, conditions for an ice dam come on about 16.4 days in a normal winter, mostly in January and December.
Tooele averages 75 inches of snow a year and about 69 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 Tooele
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 12.5 | Moderate |
| Typical, some insulation, not air-sealed | 16.4 | High |
| Older or poorly insulated, warm attic | 21.2 | High |
Sealing and insulating a typical attic takes out about 3.9 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 21.2 days.
What to do about ice dams in Tooele
- 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.
Tooele winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 14.0 | 20.6 | 5.7 |
| February | 14.6 | 14.5 | 3.2 |
| March | 11.1 | 4.9 | 0.7 |
| April | 5.9 | 1.0 | 0.1 |
| May | 0.4 | 0.1 | 0.0 |
| October | 1.9 | 0.7 | 0.0 |
| November | 10.2 | 6.4 | 1.1 |
| December | 17.2 | 20.4 | 5.6 |
Tooele next to nearby towns
Tooele ranks 20 of 67 Utah cities here for ice-dam days, behind Ogden at 37.2 days.
- Grantsville, UT 10 mi, 11.6 days
- Herriman, UT 15 mi, 17.2 days
- Magna, UT 17 mi, 10.4 days
- South Jordan, UT 17 mi, 16.2 days
- West Jordan, UT 17 mi, 10.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from Tooele, 0.8 miles from Tooele. 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.