Loudon County, TN Frost Line Depth: 12 in

Verified

12in

30 cm · 1 ft

Set in the building code Loudon County has adopted.

Source and how we checked

Document: planningandcodes.loudoncounty-tn.gov

Climate: 76 nights a year at or below 32 °F (NOAA 1991–2020, Lenoir City, 4.6 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

1 of 1nearby verified codes use the same depth
76nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

How deep is the frost line in Loudon County?

Loudon County's building authority sets the frost line depth at 12 in (30 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 Loudon County?

Tennessee leaves the frost line depth to each city or county, and Loudon County fills it in when it adopts the residential code. The value above comes from Loudon County’s own document on planningandcodes.loudoncounty-tn.gov. See how Tennessee sets frost line depth.

How deep do footings, decks and water lines need to be in Loudon County?

House or garage footing Deck footing Water service line Fence post

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

Minimum depths in Loudon County with a 12 in frost line
Project	Depth	Rule
House or garage footing	12 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	12 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	18 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	12 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 Loudon County?

Average lows are at or below freezing from Dec to Feb. 76 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 28 °F.

NOAA 1991–2020 climate normals, Lenoir City station, 4.6 mi away, elevation 785 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	28	30.7	37.4	45.5	55.2	64.1	68.1	66.8	60.2	47.6	36.6	31.3
High	48.6	53.1	62	71.4	79	85.9	89	88.4	83.5	72.9	61.2	52

Loudon County has fewer freezing nights than 41 of the 59 other Tennessee places we track. The Tennessee median is 84. Coldest: Greene County; mildest: Memphis.

What frost line depth do towns near Loudon County use?

One official code near Loudon County is verified.

Official frost line depths near Loudon County
Place	Verified frost line	Distance
Bradley County	12 in	51 mi away

How likely is the soil in Loudon County to heave?

None 100%

USDA rates the sampled soil around Loudon County as 100% none for frost action (main soils: Fullerton, Bodine, Minvale).

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 Loudon County?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Loudon County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 12 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Loudon County at a glance

Frost line depth: 12 in
Population (2023 est.): 60,591
Mean annual temperature: 59.1 °F
ZIP codes (9): 37737 · 37742 · 37771 · 37772 · 37774 · 37846 · 37874 · 37885 · 37922