Eagle Mountain, UT Frost Line Depth: 30 in

Verified

30in

76 cm · 2 ft 6 in

Set in the building code Eagle Mountain has adopted.

Source and how we checked

Document: eaglemountain.gov

Climate: 197 nights a year at or below 32 °F (NOAA 1991–2020, Fairfield, 5.5 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

4 of 4nearby verified codes use the same depth
197nights a year at or below 32 °F
50%of nearby soil rated “moderate” for frost action (USDA)

How deep is the frost line in Eagle Mountain?

Eagle Mountain's building authority sets the frost line depth at 30 in (76 cm). Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).

Who sets the frost line depth in Eagle Mountain?

Utah leaves the frost line depth to each city or county, and Eagle Mountain fills it in when it adopts the residential code. The value above comes from Eagle Mountain’s own document on eaglemountain.gov. See how Utah sets frost line depth.

How deep do footings, decks and water lines need to be in Eagle Mountain?

House or garage footing Deck footing Water service line Fence post

House or garage footing in Eagle Mountain: dig at least 30 in (76 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Minimum depths in Eagle Mountain with a 30 in frost line
Project	Depth	Rule
House or garage footing	30 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	30 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	36 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	30 in	No code rule; common practice is below the frost line

Work out posts, concrete and footing sizes with the fence post depth calculator or the deck footing calculator.

How cold does it get in Eagle Mountain?

Average lows are at or below freezing from Oct to Apr. 197 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 13.2 °F.

NOAA 1991–2020 climate normals, Fairfield station, 5.5 mi away, elevation 4,880 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	13.3	17.6	24.8	29.6	36.8	43.9	51	49.4	40.3	28.5	19.8	13.2
High	39.3	44.5	56	63	72.1	82.5	90.2	88.6	80	66.6	51.8	40.2

Eagle Mountain has more freezing nights than 24 of the 25 other Utah places we track. The Utah median is 118. Coldest: Summit County; mildest: St. George.

What frost line depth do towns near Eagle Mountain use?

4 official codes near Eagle Mountain are verified; each links to its document.

Official frost line depths near Eagle Mountain
Place	Verified frost line	Distance
Herriman	30 in	12 mi away
Riverton	30 in	14 mi away
South Jordan	30 in	17 mi away
West Jordan	30 in	20 mi away

How likely is the soil in Eagle Mountain to heave?

Low 28%Moderate 50%High 22%

USDA rates the sampled soil around Eagle Mountain as 28% low, 50% moderate, 22% high for frost action (main soils: Cheebe, Thiokol, Mountainville).

USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.

How do you confirm the frost line before you dig in Eagle Mountain?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Eagle Mountain building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 30 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Eagle Mountain at a glance

Frost line depth: 30 in
County: Utah County
Population (2023 est.): 56,932
Mean annual temperature: 47.6 °F
ZIP codes (3): 84005 · 84013 · 84045