Ice dam risk in Lehi, UT
Will your roof get ice dams in Lehi, UT?
17.2 dam days a winter
High risk. On an ordinary house in Lehi, conditions for an ice dam come on about 17.2 days in a normal winter, mostly in January and December.
Lehi averages 26 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 Lehi
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 14.2 | Moderate |
| Typical, some insulation, not air-sealed | 17.2 | High |
| Older or poorly insulated, warm attic | 21.0 | High |
Sealing and insulating a typical attic takes out about 3.0 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 21.0 days.
What to do about ice dams in Lehi
- 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.
Lehi winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 7.4 | 21.9 | 6.0 |
| February | 3.6 | 18.2 | 4.3 |
| March | 1.8 | 5.0 | 0.8 |
| April | 1.3 | 0.6 | 0.0 |
| October | 0.3 | 0.2 | 0.0 |
| November | 3.7 | 5.0 | 1.0 |
| December | 8.2 | 18.3 | 5.0 |
Lehi next to nearby towns
Lehi ranks 13 of 67 Utah cities here for ice-dam days, behind Ogden at 37.2 days.
- Highland, UT 4 mi, 17.0 days
- American Fork, UT 5 mi, 8.2 days
- Bluffdale, UT 5 mi, 17.2 days
- Saratoga Springs, UT 6 mi, 8.5 days
- Draper, UT 6 mi, 17.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Utah Lake Lehi, 4.2 miles from Lehi. 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.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.