Frost Line Depth in Bristol, Connecticut
- Bristol’s adopted code
- Checked Oct 2026
- Sources
Verified
42in
107 cm · 3 ft 6 in
Set in the building code Bristol has adopted.
Source and how we checked
Document: bristolct.gov
Climate: 142 nights a year at or below 32 °F (NOAA 1991–2020, Burlington, 7.8 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Bristol?
"{confirmed quote}". Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).
Who sets the frost line depth in Bristol?
Connecticut sets frost line depth in its state code, and Bristol’s own document lists the value above (bristolct.gov). See how Connecticut sets frost line depth.
How deep do footings, decks and water lines need to be in Bristol?
House or garage footing in Bristol: dig at least 42 in (107 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| Project | Depth | Rule |
|---|---|---|
| House or garage footing | 42 in | Below the frost line and at least 12 in deep (IRC R403.1.4) |
| Deck footing (attached) | 42 in | Below the frost line and at least 12 in deep (IRC R507.3) |
| Water service line | 48 in | 6 in below the frost line and at least 12 in deep (IRC P2603.5) |
| Fence post bottom | 42 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 Bristol?
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Average lows are at or below freezing from Dec to Mar. 142 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 17 °F.
NOAA 1991–2020 climate normals, Burlington station, 7.8 mi away, elevation 505 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 17 | 18.3 | 25.9 | 36.1 | 46.8 | 56.6 | 62.1 | 60.2 | 52.5 | 40.8 | 32.2 | 24 |
| High | 36.3 | 39.1 | 46.6 | 59.5 | 70.4 | 78.5 | 83.7 | 82 | 75.3 | 63.3 | 52.1 | 41.4 |
Bristol has more freezing nights than 10 of the 10 other Connecticut places we track. The Connecticut median is 121. Coldest: Bristol; mildest: Bridgeport.
How likely is the soil in Bristol to heave?
USDA rates the sampled soil around Bristol as 8% none, 7% low, 71% moderate, 14% high for frost action (main soils: Charlton, Chatfield, Woodbridge).
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 Bristol?
Bristol at a glance
- Frost line depth
- 42 in
- County
- Naugatuck Valley Planning Region
- Population (2023 est.)
- 61,601
- Mean annual temperature
- 50 °F
- ZIP codes (2)
- 06010 · 06062