When considering a new home, an important consideration that many put thought into is the home’s foundation. While many builders continue to build with traditional poured concrete foundations, there are also home builders that instead opt for a more robust option; an ICF foundation.
So, what exactly is an ICF foundation? What are the pros and cons of building with an ICF foundation and how exactly does an ICF foundation compare to a traditional, poured concrete foundation?
Let’s dive in…
What is an ICF Foundation?
Insulated concrete form (ICF) is a way to lay a building’s foundation. The technology was developed in the late 60s and uses interlocking polystyrene “walls”. The polystyrene is used to build the outside form of the foundation, and reinforcing rebar is placed inside within the form for added strength. Once the forms are all put in place, concrete is poured in the middle.
ICF foundations are unique in that the forms themselves become part of the foundation. While traditional concrete foundations are poured using plywood forms that are then removed, the polystyrene forms stick to the concrete, causing a built-in, immovable insulated layer.
Pros of ICF Foundations
There are many advantages to ICF foundations, especially in colder climates. ICF foundations offer more controlled, consistent insulation from cold and moisture, are stronger and more durable over time, and are more energy efficient than poured foundations.
ICF Foundation Strength
ICF foundation uses more rebar in the foundation than traditional forming, making it far stronger. Rebar adds tension-resisting forces to the concrete, increasing the overall strength of the structure. Concrete has incredible strength in resisting compressive force, but is relatively weak regarding tensile force, so the extra rebar used in ICF foundations doesn’t make the concrete stronger, but makes the foundation stronger as it is able to undertake loads from multiple kinds of force.
ICF Foundation Durability
When it comes to durability, ICF has you covered. Because the forms themselves are made of a permanent insulation, you are not at risk of your insulation falling out, being forgotten, or only being partially put in place.
At Lincolnberg, the interior of the foundation is covered with drywall for an added layer of protection rather than traditional foundations that are only covered with a thin layer of polyethylene (plastic sheeting). The exterior of the foundation is covered with a membrane that wicks away moisture, and, because of this, dirt never touches the foundation wall. Keeping dirt away from the foundation protects it from mould, decay, and any leaking. Being completely surrounded by insulation, the cold is not able to move through the concrete as quickly as a traditional poured concrete foundation. This prevents frost from forming on the inside of the concrete wall behind the traditional fiber insulation. In the winter this is not a problem, but when the wall warms up in May it causes leaking in the basement.
ICF Foundation Cost
Cost can often be an issue when it comes to choosing ICF foundations or traditional. Some builders have been known to charge upwards of five thousand dollars to pour foundations using ICF. However, Lincolnberg Homes uses our own skilled employees to do this work, bringing the cost down and the ICF foundation is included in the price of all single-family homes.
Cons of ICF Foundations
There aren’t many negatives to ICF foundation, but one is that the installation is a little trickier.
When it comes to installation, the cribbers must be mindful to be extra careful that there is enough bracing on and around all the forms. If the cribbers don’t watch the forms carefully enough, there can be blowouts where concrete spills out of the forms, which negates the purpose of a surrounding layer of insulation. That’s why Lincolnberg sites ensure that all the forms are properly braced before any concrete pours.
One other potential fallback for ICF foundations is that because the insulation is outward facing as well, in warm climates insects have been known to burrow into the insulation. That’s not a risk here in Edmonton though, we are anything but a warm climate!
ICF vs Traditional Foundations
The main difference between ICF foundations and traditional ones is that for ICF the forms become a permanent fixture for the structure (because they are made of a hard, polystyrene insulation) and traditional foundations are made with plywood forms that are then removed, and insulation is added to the interior facing wall after the concrete has cured. Other differences include more rebar being used in ICF foundations to improve tensile strength, and more protection from the elements.
Insulated concrete forms keep the concrete from freezing which protects the concrete from frost and moisture, so there is less risk of rot and mould. There are far more benefits to ICF foundations than drawbacks, especially when you live in a cold climate like Alberta. You get more strength, more durability, and, best of all, when you choose Lincolnberg Master Builders you get an ICF foundation with every single-family home at no extra cost to you!
Choosing your foundation style is easy when you work with Lincolnberg, because they choose quality and longevity when they use an ICF foundation.