If you are starting a construction project in the late fall as the winter starts to bare down on you then you’re going to have to take some steps to protect your footings and foundation from frost.
Why do you have to protect your footings and foundation walls from frost? When frost is able to enter the ground it freezes the water in the dirt, when the water freezes it expands the dirt. This expansion causes the ground to move, when the ground moves it moves with a tremendous force, a force so powerful that it can move concrete footings and walls that weight many tons. This causes the walls and footings to be uneven and also can damage them by cracking or breaking the concrete.
There is a way to protect your foundation from this happening, no matter how cold it gets you should be able to protect your foundation from frost heave, you have to take the time to protect the foundation and the excavated hole before the frost gets the opportunity to enter the ground and freeze it.
The simplest way to protect the footings while you are constructing them is to cover them with insulated tarps or insulated poly blankets as they are called by some suppliers. These tarps can be spread over and area and use the heat from the ground and the concrete to keep the frost from entering the ground. There are some problems with using insulated tarps;
• if there are high winds then the tarps can be blown out of position allowing the cold to penetrate,
• they can be difficult to position around piers and tightly positioned forms,
• If they are used for long periods of time in extremely cold weather they might not be enough to keep the frost from penetrating the ground underneath them.
The other way to protect your footings and foundation from frost penetration is to cover the entire excavated hole with straw. Straw is cheap to buy but labour intensive to spread around, you also have to figure on removing it once it’s time to backfill the excavated hole. Straw cannot be left in the hole it must be removed as it can cause problems even if its buried next to the wall.
If you fork the straw around the hole and make it about 1 foot deep then it should protect the foundation and excavated hole from any weather no matter what the temperature or weather ends up. Straw has the unique ability to generate its own heat, this means that it doesn’t have to rely on the ground heat to keep the frost at bay.
Whatever you do you must to something, the worst thing you can do is allow the frost to penetrate the ground and get under your foundation.
Village Builders Inc.