Ice dam risk in Monument, CO
Ice dams in Monument, CO: how often
22.2 dam days a winter
High risk. On an ordinary house in Monument, conditions for an ice dam come on about 22.2 days in a normal winter, mostly in January and December.
Monument averages 121 inches of snow a year and about 86 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 Monument
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 16.9 | High |
| Typical, some insulation, not air-sealed | 22.2 | High |
| Older or poorly insulated, warm attic | 28.8 | High |
Sealing and insulating a typical attic takes out about 5.3 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 28.8 days.
What to do about ice dams in Monument
- 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.
- Heat cable is worth pricing here even on a sealed house, along the eave and in the gutters and downspouts it drains into.
Running 60 feet of 5 W/ft cable whenever snow lies below freezing would use about 95 kWh a winter in Monument, roughly $16 at 17 cents a kWh.
Which to spend on first: air sealing or heat cable.
Monument winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 14.4 | 18.8 | 5.5 |
| February | 10.9 | 16.9 | 4.7 |
| March | 24.2 | 11.7 | 2.9 |
| April | 23.7 | 7.5 | 1.3 |
| May | 3.3 | 1.5 | 0.1 |
| September | 1.7 | 0.2 | 0.0 |
| October | 11.1 | 3.2 | 0.4 |
| November | 18.4 | 8.4 | 2.2 |
| December | 13.4 | 17.5 | 5.2 |
Monument next to nearby towns
Monument ranks 3 of 53 Colorado cities here for ice-dam days, behind Steamboat Springs at 51.0 days.
- Colorado Springs, CO 15 mi, 5.4 days
- Castle Rock, CO 21 mi, 11.5 days
- Castle Pines, CO 27 mi, 11.5 days
- Fountain, CO 28 mi, 5.4 days
- Parker, CO 30 mi, 11.5 days
Where these numbers come from
NOAA 1991–2020 climate normals from Monument, 2.3 miles from Monument. 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.