Frostline.info

Frost line depth in Brandon, VT 05733

Frost can reach about 39 inches deep in typical soil here (34″ in clay to 49″ in sand). Local codes in climates like this commonly set footing depth at 36 to 48 inches.

Deep frost
Estimated frost depth
39″
typical silt/loam soil
Typical code footing depth
36–48″
rule of thumb for this climate
Design freezing index
1,577
°F-days, 100-year winter
Mean annual temp
46.1°F
nearest stations
39″ 0″12″24″36″48″60″72″ 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)49″
Silt / loam (typical yard soil)39″
Clay (holds water)34″

Estimates use the modified Stefan equation with a turf / light-snow surface. Bare, plowed or paved ground freezes deeper; deep snow cover keeps frost shallower. How we calculate this.

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 Rutland County building or permitting office in Vermont and call 811 before digging.

What this means for your project in Brandon

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 48″ 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 39″ 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; in a climate this cold, 4 feet or more is common for service lines.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 1,577 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather data behind this estimate

NOAA weather stationDistance100-yr AFI
Cornwall, VT11.8 mi1,683
Rutland, VT15.5 mi1,388
Whitehall, NY23.6 mi1,594

05733 ranks #6 of 25 ZIP codes in Rutland County for frost depth (1 = deepest).

Nearby ZIP codes

All of Rutland County →

Common questions

How deep is the frost line in Brandon, VT?

Based on NOAA's 100-year air freezing index of 1,577 °F-days for 05733, frost can reach about 39 inches in typical soil, 34 inches in clay and 49 inches in sand or gravel.

How deep do deck footings need to be in 05733?

Footings must sit below the local frost line and at least 12 inches below undisturbed soil. In climates like Brandon, codes commonly set the depth at 36 to 48 inches. The Rutland County building department sets the exact requirement.

Why does soil type change the frost depth?

Wet clay holds a lot of water, and freezing that water releases heat that slows the frost. Dry sand and gravel hold little water and conduct cold faster, so frost goes deeper.

Where does this data come from?

Freezing-index values come from NOAA National Climatic Data Center station records (1951–80), the same data behind the air-freezing-index map in the International Residential Code. We average the three nearest stations, weighted by distance.