How deep is frost line in my area?
3 min read
Asked by: Shannon Gomez
You may wonder how deep the frost line is. It can vary wildly. In the coldest climates in the USA, the frost depth can be deeper than eight feet. In warmer parts of the country, the frost depth may be less than one foot.
How do I find the frost line depth in my area?
Testing the exact depth relies on instruments known as frost tubes that consist of a small hollow tube that is inserted into a drilled hole in the frozen ground. Testers put a bag of water with measurement indicators into the tube and determine the depth based on the line at which the water freezes.
How deep is the frost line in the ground?
The line varies by latitude, it is deeper closer to the poles. Per Federal Highway Administration Publication Number FHWA-HRT-08-057, the maximum frost depth observed in the contiguous United States ranges from 0 to 8 feet (2.4 m). Below that depth, the temperature varies, but is always above 32 °F (0 °C).
How deep do footings need to be for frost?
12 inches
Depth of Footings
Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.
What is the frost line in New Jersey?
Did you know that here in New Jersey the frost line is 36 inches, which means that below 36 inches the water never freezes? So, even when its 10 degrees outside there is still flowing water around your basement floor and foundation.
How far below frost line should fence post be?
2 feet
However, when all is said and done, setting your posts at least 2 feet underground is a safe bet. Frost heaves can also push up plants and expose roots to damaging wind and cold, not to mention poorly prepared roads and sidewalks.
Do fence posts need to go below frost line?
All fence posts should be cemented in the ground below frost level. Check your local frost level and dig deeper by at least 6″.
How deep does the ground freeze in New Jersey?
Here are the 10 states with the deepest frost lines: Alaska (100 inches) Minnesota (80 inches)
Frost Lines by State 2022.
| State | Frost Lines (Inches) |
|---|---|
| New Jersey | 36 |
| Indiana | 36 |
| Illinois | 36 |
| Connecticut | 36 |
What is the minimum footing depth in New Jersey and why?
Footings: Must comply with I.R.C. 2015, N.J. Edition, Section R507. The footing maybe a minimum of twelve inches (12”) in diameter and at a depth below the frost level of thirty inches (30”) from finish grade to the bottom of the footing.
How deep should I dig for a deck post?
Dig the holes six inches deeper than the required frost line depth for your area, and slightly wider than the concrete footer tubes you’ll be using.
Why deck posts should not be set in concrete?
Deck Posts Will Rot When Set in Concrete
The concrete around the post is acting as a bowl holding water. Just like a concrete swimming pool holds water, so does concrete around a deck post. The rain falls and collects on top of the concrete with no place to go except into the post.
Do deck footings need rebar?
Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. However, placing reinforcing steel within footings is a relatively easy and inexpensive practice that can provide increased performance.
