Ice dam risk in Bountiful, UT
Will your roof get ice dams in Bountiful, UT?
20.7 dam days a winter
High risk. On an ordinary house in Bountiful, conditions for an ice dam come on about 20.7 days in a normal winter, mostly in January and December.
Bountiful averages 119 inches of snow a year and about 89 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 Bountiful
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 14.4 | Moderate |
| Typical, some insulation, not air-sealed | 20.7 | High |
| Older or poorly insulated, warm attic | 28.7 | High |
Sealing and insulating a typical attic takes out about 6.3 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 28.7 days.
What to do about ice dams in Bountiful
- 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.
Bountiful winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 25.0 | 25.2 | 7.2 |
| February | 21.4 | 20.0 | 4.4 |
| March | 17.8 | 9.6 | 1.1 |
| April | 10.7 | 2.7 | 0.2 |
| May | 1.1 | 0.0 | 0.0 |
| September | 0.1 | 0.0 | 0.0 |
| October | 2.8 | 1.0 | 0.0 |
| November | 16.2 | 7.6 | 1.2 |
| December | 23.8 | 23.0 | 6.6 |
Bountiful next to nearby towns
Bountiful ranks 10 of 67 Utah cities here for ice-dam days, behind Ogden at 37.2 days.
- Woods Cross, UT 3 mi, 16.0 days
- North Salt Lake, UT 3 mi, 16.0 days
- Centerville, UT 4 mi, 20.7 days
- Salt Lake City, UT 8 mi, 11.0 days
- Farmington, UT 8 mi, 20.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from Bountiful Bench, 1.4 miles from Bountiful. 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.