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).

What is my freeze line?

The frost line is simply the deepest point in the ground to which ground water will freeze. It’s also referred to as the frost depth. When water changes from liquid to solid, it expands 9% in volume. This resulted frost heave can be detrimental to footings and foundations.

Where is the frost line in the ground?

What is the Frost Line? The frost line is the deepest depth at which the moisture present in the soil is expected to freeze. Once the bottom of your footings is buried below the frost line, the residual heat in the ground below the footing will ensure the soil below the footing will not freeze in the winter.

How far down do you dig for deck posts?

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.

How far below frost line should deck footings be?

By code, the bottom of a footing must be at least 12 inches deep and below the local frostline—whichever is deeper—and bear on stable, undisturbed soil that is free of organic matter.

How deep should fence post be in PA?

Dig holes

Posts need to be set below the frost line to prevent heaving. For regular privacy fences, holes need to be at least 36 inches deep or half the fence height, whichever is greater, plus six inches for base gravel. Lower fences will not likely need to be as deep (or you may use ground spikes instead).

How deep do footings need to be in PA?

Footings shall be minimum 20 inches square or 22 inches diameter (Figure 5). Bottom of footings shall be a minimum of 24 inches below grade and shall bear on solid ground.

How deep does a water line have to be in the ground?

Reliability and safety should always be considered, as well as local, state, and national codes. Water filled pipe should be buried at least 12″ below the maximum expected frost line.

How deep is the frost line in Canada?

As you can see in Canada, the required footing depth varies from 18” to 96” below grade. Our vast countries has many different frost levels. This varying in frost level affects how deep the deck footings will need to be dug in.

Do fence posts need to be below frost line?

For example, a 6-foot tall fence will need at least 2 feet of post in the ground. Consider the frost line in your area. The bottom of the post needs to sit below the frost line (consult local codes for exact requirements). The frost line (also called frost depth) varies from region to region.

What is the ground temperature below the frost line?

Ground frost occurs when the ground contains water, and the temperature of the ground goes below 0° C (32° F).

How does frost penetrate the ground?

The penetration of frost into a highway section is a heat-flow process; soil freez- ing occurs when the soil loses heat to the atmosphere above and the temperature of the soil drops below the freezing point.

How deep is the frost line in southwest Missouri?

Browning says a local city engineer says the frost line in Jasper County is located at about 18 to 24 inches. In central Missouri, the frost line is considered to be 30 to 36 inches. But, central and part of southwest Missouri are in the same USDA growing zone.

Can I set deck posts without concrete?

Plastic piers require the digging, but unlike footings, there is no concrete involved. The pier is put into the hole and attached the post, giving you your deck without wasting hours installing footings.

How deep and wide do footings need to be?

The minimum depth of footings below the surface of undisturbed soil, compacted fill material or controlled low strength material (CLSM) shall be 12 inches (305 mm). Where applicable, the requirements of CBC Section 1809.5 shall also be satisfied. The minimum width of footings shall be 12 inches (305 mm).

Do deck footings need to be below the frost line?

Footings typically must extend below the frost line to prevent shifting during freeze-thaw cycles. Dig footing holes about 6 inches deeper than required. Fill the bottom of the hole with 6 inches of gravel and compact the gravel with a 2×4 or wood post.