#Placing footing per frost depth how to#
#Placing footing per frost depth code#

#Placing footing per frost depth code#

You can enter a zip code into internet tools to find out the potential frost depth where you’re building. These are merely guidelines, and it’s advisable to speak with your neighborhood building inspector to find out the actual frost depth where you’re planning to build. On a frost depth map, you will frequently find contour lines where any position along the line denotes the frost depth in the towns and cities where the line crosses. Map of Frost DepthĪ frost depth map is a helpful tool for estimating how far you should dig into the ground to reach an area where the ground doesn’t often freeze. Frost has the ability to readily lift the earth by six or more inches. Each ice lens that forms lifts the lenses above it higher into the atmosphere. Within the soil, these various water bodies turn into ice lenses. Like the layers on a sandwich, the liquid water in the soil frequently occurs in layers. Instead of being driven into the compacted ground, this excess volume is pushed upward into the air. When water freezes into solid form, it expands by 9%. As a result, the soil underneath the surface layer that has frozen also freezes. The soil temperature can start to closely match the air temperature if the air temperature is far below 32 F. The soil that is in touch with the air starts to freeze as temperatures drop below freezing. The enormous uplift force might seriously harm the structural integrity of your deck. The uplift force produced by the expanding freezing water can lift the footing and anything on it should the soil beneath the footing freeze. Things weighing hundreds of pounds can and do get lifted by frost heaving.

Just as you shouldn’t build on the unstable ground where the weight of the building will produce uneven downhill settling that could lead to the structure’s collapse, you also don’t want your deck to lift up unevenly. Making sure the structure’s base won’t move over time is your first concern while building anything. The Frost Line in Construction: Why Is It Important? You might need to dig your foundation much deeper than on flat terrain to achieve an appropriate lateral barrier. The minimum distance to grade must be maintained both vertically and laterally if you are building into a steep hillside or next to a retaining wall. Additionally, footings must be inserted at least 12″ below unstable soil. If you live in a warm climate, such as South Florida, where frost is infrequent, you might be able to set your footings directly on the ground, but in really cold climates, such as Minnesota and Canada, you will need to dig down at least 96 inches.Īlways ask your local building inspector what is needed in your community. The soil beneath your footings won’t freeze in the winter until the bottoms of your footings are buried below the frost line due to the remaining heat in the earth.ĭepending on your location, you may need to put your frost footings at a different depth. The depth below which soil moisture is anticipated to freeze is known as the frost line. The depth of the frost may be less than one foot in areas of the country that are warmer. The depth of the frost can reach more than eight feet in the coldest regions of the USA.

You might be curious about the frost line’s depth.

The depth you need to dig to go below the frost line in your town or city must then be determined by consulting a frost depth map or speaking with your local building inspector. In order to support the concentrated load applied on each deck pier, you must first have adequate soil conditions. Two factors determine the depth of your deck footing.

#Placing footing per frost depth how to#

This article describes how to create strong foundations that will stand firm all year long. They won’t heave or move as the ground freezes and thaws with the change in the weather if positioned below the frost line. Aside from using the traditional deck footings, you can also utilize the concrete footing blocks. Your deck footings should be dug and poured so that they are below the frost line. By properly pouring concrete footings for posts, you can avoid frost-heave damage.