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Frost lines vary by latitude and are deeper closer to the poles. According to the Federal Highway Administration, the maximum frost depth ranges between zero to eight feet in the contiguous United States. Generally, the coldest U.S. states have the deepest frost lines.
How do I find my frost line?
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 is Frostline Ontario?
I believe 4 feet is the deepest recorded frost line in Ontario, hence why to be safe, you should go down at least 4 feet.
Do footers need to be below frost line?
Most building codes in cold-climates require foundation footings be placed below the frost line, which can be about 4-feet deep in the northern United States. The goal is to protect foundations from frost heaving.
How deep do you have to 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. A power auger can make this step easier and faster.
How deep should footers be for a deck?
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.
Why do you have to dig below 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 can you tell if there is frost in the ground?
Just walking across your soil or patting it with your hand will give away whether it is still frozen or not. Frozen soil is dense and rigid. Frozen soil feels very solid and does not give way under foot.
What temperature does ground freeze?
When the temperature of the ground drops below 0° Celsius (32° Fahrenheit), it freezes. However, the ground temperature can be different from the temperature of the air above it. Layers deep within the ground may be colder or warmer than layers near the surface of the ground.
How deep do fence posts need to be in Ontario?
4 Foot deep is best for posts using about 2-3 bags of cement per post. Anything between 1-3 feet and your fence post will heave up. 4′ is minimum, don’t listen to your contractor – 3 feet is not enough. Winters have been getting milder in Toronto, so the frost probably doesn’t go as deep anymore.
How deep do deck footings need to be in Ontario?
Decks cannot be attached to a house unless proper footings are in place to a depth of at least 4′ and have a minimum footing size of 24” x 24” x 8” or incorporate a 24” Bigfoot and have a minimum of an 8” Sonotube.
How deep is the frost line in Thunder Bay?
In the Thunder Bay area, the frost penetration in unprotected areas such as roadways and parking areas can be as deep as 2.4 m. Accordingly, the minimum soil cover for perimeter shallow foundations of unheated structures placed on soil and for services is 2.4 m.
How deep should frost walls be?
It needs to be thick enough to allow the concrete to reach the bottom. 6″ might be marginal for a 4′-6″ depth, even if both sides are formed. It might need to be 8″ to 12″ thick if one or both sides are cast against the dirt.
Is frost depth top or bottom of footing?
Frost depth always has been and should be to the bottom of the footing. You are trying to avoid a condition where frost occurs in the soil directly under a footing and in which case the soil expands (or rather the moisture freezes and expands within the soil matrix) and dislocates the footing.
Why deck posts should not be set in concrete?
A deck post should always be placed on top of footing, not inside concrete because it can break. Concrete tends to absorb moisture and wood expands when it gets wet, so these two factors combined will result in the wood breaking the concrete.
Is 2 feet deep enough for fence posts?
2 feet is the minimum depth that you should dig your fence post holes for. To dig the holes one-third to one-half of the post’s aboveground height, is a general formula. The deeper you dig the holes, the more stability your fence has.
Do deck posts need to be below frost line?
There are several ways to set deck posts; we recommend attaching the posts to concrete footers above the ground. This helps to prevent wooden posts from rotting. Set footers a minimum of 6” below the frost line for your area to prevent movement during freezing temperatures.
How long does it take for footer to cure before laying block?
Assuming you are using 3,000-psi concrete for the footings, you should be safe installing the anchors after 28 days in most circumstances. But there are a few things that can greatly alter the “normal” rate of strength gain: concrete temperature and the use of fly ash or admixtures.
How do you frost protect footings?
The footings of most foundations are placed below the frost depth. Either extruded-polystyrene (XPS) or denser types of expanded-polystyrene (EPS) insulation may be used to insulate a frost-protected shallow foundation.
Do I need rebar in deck footing?
Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. Footings with large bearing areas or unstable soil can benefit from adding rebar to prevent cracking.
How far down is below frost line?
Frost lines vary by latitude and are deeper closer to the poles. According to the Federal Highway Administration, the maximum frost depth ranges between zero to eight feet in the contiguous United States.
How deep should a deck footing 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. And the code requires a minimum compressive strength of 2,500 psi for the concrete.
How do you tell if there is frost in the ground?
Just walking across your soil or patting it with your hand will give away whether it is still frozen or not. Frozen soil is dense and rigid. Frozen soil feels very solid and does not give way under foot. Test your soil first by walking on it or patting it in several locations.
How deep should water lines be buried?
The classic rule-of-thumb procedure for avoiding cold-weather damage to water pipe is “bury it deep.” If water lines are located below the lowest level of frost penetration—five to six feet or more in many cold region locales—they should be safe from freezing.
How deep should a deck post be?
Set footers a minimum of 6” below the frost line for your area to prevent movement during freezing temperatures. Pour about 6 inches of all-purpose gravel into postholes and pack the gravel tight by using the end of a wooden post.
Does footing need to be below frost line?
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.
How many footings do I need for a 12×12 deck?
For an attached 12 x 12′ deck, you’ll need at least 3 footings, plus at least 2 more if you’re planning on building stairs with it. If your deck will be a different size, it’s easy to figure out how many you’ll need.
