Frost Line Depth in Nashville-Davidson, Tennessee
- Nashville-Davidson’s adopted code
- Checked Oct 2026
- Sources
Verified
12in
30 cm · 1 ft
Set in the building code Nashville-Davidson has adopted.
Source and how we checked
Document: up.codes
Climate: 75 nights a year at or below 32 °F (NOAA 1991–2020, Shelby Bottoms Nature, 3.4 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Nashville-Davidson?
Nashville-Davidson'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 Nashville-Davidson?
Tennessee leaves the frost line depth to each city or county, and Nashville-Davidson fills it in when it adopts the residential code. The value above comes from Nashville-Davidson’s own document on up.codes. Davidson County uses the same 12 in, so the depth does not change at the city limits. See how Tennessee sets frost line depth.
How deep do footings, decks and water lines need to be in Nashville-Davidson?
House or garage footing in Nashville-Davidson: dig at least 12 in (30 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| 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 Nashville-Davidson?
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Average lows are at or below freezing from Dec to Feb. 75 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 27.5 °F.
NOAA 1991–2020 climate normals, Shelby Bottoms Nature station, 3.4 mi away, elevation 405 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 27.5 | 31.2 | 38.6 | 47.4 | 55.7 | 63.9 | 67.9 | 67 | 59.3 | 47.2 | 36.7 | 31.7 |
| High | 48 | 52.2 | 61.9 | 72 | 79.9 | 86.7 | 89.3 | 88.6 | 83.6 | 73.2 | 61.6 | 51.1 |
Nashville-Davidson has fewer freezing nights than 43 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 Nashville-Davidson use?
4 official codes near Nashville-Davidson are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Hendersonville | 12 in | 14 mi away |
| Cheatham County | 12 in | 19 mi away |
| Murfreesboro | 12 in | 30 mi away |
| Maury County | 10 in | 42 mi away |
How likely is the soil in Nashville-Davidson to heave?
USDA rates the sampled soil around Nashville-Davidson as 100% none for frost action (main soils: Urban land, Maury, Stiversville).
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 Nashville-Davidson?
Nashville-Davidson at a glance
- Frost line depth
- 12 in
- County
- Davidson County
- Population (2023 est.)
- 687,788
- Mean annual temperature
- 59.3 °F
- ZIP codes (37)
- 37013 · 37015 · 37027 · 37064 · 37072 · 37076 · 37080 · 37086 · 37115 · 37122 · 37135 · 37138 · 37143 · 37189 · 37201 · 37203 · 37204 · 37205 · 37206 · 37207 · 37208 · 37209 · 37210 · 37211 · 37212 · 37213 · 37214 · 37215 · 37216 · 37217 · 37218 · 37219 · 37220 · 37221 · 37228 · 37232 · 37238