Cumberland County, TN Frost Line Depth: 12 in

Verified

12in

30 cm · 1 ft

Set in the building code Cumberland County has adopted.

Source and how we checked

Document: cumberlandcountytn.gov

Climate: 84 nights a year at or below 32 °F (NOAA 1991–2020, Crossville Mem Airport, 4.8 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

2 of 2nearby verified codes use the same depth
84nights a year at or below 32 °F
64%of nearby soil rated “moderate” for frost action (USDA)

How deep is the frost line in Cumberland County?

Cumberland 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 Cumberland County?

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

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

House or garage footing Deck footing Water service line Fence post

House or garage footing in Cumberland 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 Cumberland 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 Cumberland County?

Average lows are at or below freezing from Dec to Feb. 84 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 26.4 °F.

NOAA 1991–2020 climate normals, Crossville Mem Airport station, 4.8 mi away, elevation 1,867 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	26.4	29.5	35.7	44.4	52.9	60.4	64.4	63.1	56.6	45.2	35.6	30.2
High	44.3	48.1	56.3	66.4	73.5	80.1	83.2	82.7	77.3	67.5	56.3	47.4

Cumberland County has fewer freezing nights than 28 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 Cumberland County use?

2 official codes near Cumberland County are verified; each links to its document.

Official frost line depths near Cumberland County
Place	Verified frost line	Distance
Loudon County	12 in	41 mi away
Bradley County	12 in	56 mi away

How likely is the soil in Cumberland County to heave?

None 36%Moderate 64%

USDA rates the sampled soil around Cumberland County as 36% none, 64% moderate for frost action (main soils: Ramsey, Lily, Hendon).

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 Cumberland County?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Cumberland 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.

Cumberland County at a glance

Frost line depth: 12 in
Population (2023 est.): 64,760
Mean annual temperature: 55.3 °F
ZIP codes (11): 37337 · 37367 · 37723 · 37854 · 38555 · 38558 · 38571 · 38572 · 38574 · 38578 · 38583