Frostline.info

Frost line depth in Orleans Parish, Louisiana

Frost reaches about 4 inches in typical soil across Orleans Parish. Codes in this climate commonly set footing depth at 12 inches (code minimum).

Shallow frost
Estimated frost depth
4″
typical silt/loam soil
Typical code footing depth
12″ minimum
rule of thumb for this climate
Design freezing index
19
°F-days, 100-year winter
ZIP codes covered
22
#56 of 64 counties in LA (1 = deepest)
4″ 0″12″24″36″ ground frozen
Est. frost (typical soil) Typical code footing depth Clay–sand range

Frost depth by soil type

Soil typeEst. frost depth
Sand / gravel (drains well)5″
Silt / loam (typical yard soil)4″
Clay (holds water)4″

County average. Methodology.

Verify before you dig. These are climate-based estimates. The legally required frost depth is the figure your building department publishes in its IRC Table R301.2 (climatic and geographic design criteria). Call the Orleans Parish building or permitting office in Louisiana and call 811 before digging.

Frost depth by ZIP code in Orleans Parish

ZIPCityEst. frostCode range
70112New Orleans4″12″ minimum
70113New Orleans4″12″ minimum
70114New Orleans4″12″ minimum
70115New Orleans4″12″ minimum
70116New Orleans4″12″ minimum
70117New Orleans4″12″ minimum
70118New Orleans4″12″ minimum
70119New Orleans4″12″ minimum
70122New Orleans4″12″ minimum
70124New Orleans4″12″ minimum
70125New Orleans4″12″ minimum
70126New Orleans4″12″ minimum
70127New Orleans4″12″ minimum
70128New Orleans4″12–18″
70129New Orleans5″12–18″
70130New Orleans4″12″ minimum
70131New Orleans4″12″ minimum
70139New Orleans4″12″ minimum
70145New Orleans4″12″ minimum
70146New Orleans4″12″ minimum
70163New Orleans4″12″ minimum
70170New Orleans4″12″ minimum

What this means for your project in Orleans Parish

Deck footings & piers

Footings must bear below the frost line and at least 12″ below undisturbed ground. For planning in this area, budget for holes around 12″ deep until your permit office confirms the exact figure.

Fence posts

Set posts at least one-third of their above-ground height. Where frost heave is a problem, carry concrete footings below the frost line (about 12″ here in typical soil) and bell or taper the bottom.

Water & irrigation lines

Bury supply lines below the frost depth. Your water utility or plumbing code sets the minimum cover; freezing is rare, but exposed pipes still need insulation.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 19 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
New Orleans Moisant, LA12 mi18
Reserve, LA31 mi22
Covington 4 Nnw, LA39 mi23
Picayune, MS44 mi22

Nearby counties

Common questions

What is the frost line depth in Orleans Parish?

About 4 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 4 to 5 inches.

How deep should footings be in Orleans Parish, Louisiana?

Codes in climates like this commonly require 12 inches (code minimum). The Orleans Parish building department publishes the required frost depth in its adopted code (IRC Table R301.2).

Does frost depth vary within Orleans Parish?

Very little. Estimates across the county stay within 1 inches. Soil type matters more than location here.