Ice dam risk in Highland, UT
Will your roof get ice dams in Highland, UT?
17.0 dam days a winter
High risk. On an ordinary house in Highland, conditions for an ice dam come on about 17.0 days in a normal winter, mostly in January and December.
Highland averages 74 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 Highland
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 12.5 | Moderate |
| Typical, some insulation, not air-sealed | 17.0 | High |
| Older or poorly insulated, warm attic | 22.5 | High |
Sealing and insulating a typical attic takes out about 4.4 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 22.5 days.
Preventing ice dams on a Highland 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.
Highland winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 17.4 | 21.9 | 6.1 |
| February | 13.6 | 18.2 | 4.1 |
| March | 9.6 | 5.0 | 0.7 |
| April | 6.2 | 0.6 | 0.0 |
| May | 0.5 | 0.0 | 0.0 |
| October | 1.6 | 0.2 | 0.0 |
| November | 8.0 | 5.0 | 0.9 |
| December | 17.5 | 18.3 | 5.2 |
Highland next to nearby towns
Highland ranks 18 of 67 Utah cities here for ice-dam days, behind Ogden at 37.2 days.
- Alpine, UT 3 mi, 17.0 days
- American Fork, UT 3 mi, 8.2 days
- Lehi, UT 4 mi, 17.2 days
- Pleasant Grove, UT 5 mi, 8.2 days
- Draper, UT 6 mi, 17.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Alpine, 2.9 miles from Highland. 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.