Concrete is one of the most common building materials, and it has a huge planetary cost.
But what if you could construct with concrete more in an eco-friendly manner? Yes – with insulated concrete forms!
In our blog today, we will discuss about Concrete environmental impact and how ICF is able to reduce carbon foot print of Concrete up to 80%.
Let’s get started!
Concrete’s Environmental Impact
You encounter concrete every day without really thinking about it. It’s in the buildings where you work and live. The streets and sidewalks you drive and walk on. Concrete is everywhere!
But here’s the troubling truth: concrete is devastating to the environment.
Concrete production produces:
- 8% of the world’s CO2 emissions – higher than the aviation fuel!
- Tons of air-polluting particulates
- Toxic wastewater
- Endless dunes of sand – ruining rivers and seas
In fact, concrete is the second most used substance on Earth after water! And, with demand still increasing, the damaging environmental impacts of concrete only continue to worsen.
As you can see, we need more sustainable ways to build with concrete.
What Are Insulated Concrete Forms?
Unlike traditional concrete construction, a green building method is with insulated concrete forms (ICFs).
ICFs are foam insulation forms that hold concrete. The forms are hollow and remain fixed after the concrete sets.
Foam insulation typically is polystyrene or polyurethane based. ICF systems are blocks or panels that interlock like Lego bricks.
ICF construction may sound futuristic, but it is an oddly simple process. The basic steps are:
- Stack the ICF blocks in the shape of the walls
- Secure rebar inside the hollow foam forms
- Pour concrete into the forms
- Let the concrete cure – your walls are done!
The forms are made of foam. They create an insulating concrete sandwich – rigid polystyrene foam on each side of the concrete core.
Superiority of ICF Construction
A little-known fact that the general public probably does not know about concrete is that for concrete to reach its full engineered compression strength is for the concrete to cure as slowly as possible and this takes time and the thicker the concrete the more time it takes. A typical 4” thick monolithic slab takes at least 28 days to cure to attain the common engineering requirements of 3500 pounds per square inch. The surface may seem very strong a day after the pour, but that does not mean it is ready to be built upon.
Many appliers will order the concrete supplier to add certain chemicals to the mix usually during the pouring process to make the surface to harden quickly so they can finish the concrete faster and even remove the forms the same day as the pour. This may seem benign, but it is not because these chemicals are caustic and corrode the steel reinforcement unseen. Another factor is the same process can cause unseen contraction fractures inside the concrete that may not show up on the surface as much as a year later and obviously this is too late because a weight bearing structure is already built upon it.
More conscientious builders will restrain from this common practice and may employ several practices such as keeping the concrete surface wet and covering the concrete with plastic sheeting to allow the natural chemical heating inside the concrete to continue and for it to reach its full potential strength and not begin construction on the slab or concrete walls for 14-28 days.
This is a way that ICF forms are superior to typical cast in place concrete walls using metal or wood forms because the insulated forms hold the heat generated by the chemical reaction in the slurry to take place as well as retaining the moisture needed to reach its full compression strength. When all these factors are taking place in an ICF formed concrete wall when completely cured it will be nearly twice as strong as a common cast in place wall of the same thickness.
Furthermore, an ICF wall has nearly twice as much strategically placed reinforcement steel as part of the engineered form as regular cast in place walls. This is why they perform superiorly against floods and seismic events than regularly poured concrete walls which will crumble and collapse in on one another especially in an earthquake. This I witnessed firsthand when I went to Haiti as a consultant immediately after their major earthquake in 2010.
Lastly ICF walls require 1/3 to ½ as much concrete as a conventional poured wall of the same specified engineering requirements.
Advantages of Insulated Concrete Form Construction
There are a lot of advantages with ICFs compared to traditional pouring into plywood or metal forms:
Energy Efficiency
Bonded to the concrete, the foam insulation increases energy efficiency considerably over ordinary concrete walls.
ICF walls provide:
- Higher R-values – increased resistance to heat flow
- Insulation – bags less air leak
- Thermal mass – absorbing and slowly releasing heat
All these point to decreased heating and cooling costs – up to 50% lower!
Material Efficiency
Thinner concrete walls are possible since ICF walls are heavily insulated.
Regular concrete walls have to be thick to have insulation in them – usually 8″ thick or more.
In fact, ICF concrete walls measure only 4-6” thick.
This cuts down significantly on concrete, and thus carbon footprint.
Strength and Durability
Foam and concrete bonded together with rebar create walls with stunning strength.
ICF walls can withstand:
- 150 mph winds
- Seismic forces
- And it settles temperature variations
Indeed, ICF construction is the only building system to meet the highest performing building codes throughout North America.
Even better, the water-resistant foam also protects the concrete from moisture damage. This results in extremely durable, hard-wearing buildings.
Healthier Indoor Environment
ICF walls are so much less leaky than regular wall systems.
This means:
- Less dust and allergens entering the home
- Cleaner indoor air for better health
- Prevention of mold/mildew by eliminating moisture intrusion
ICFs are one of the best ways to create a healthy, comfortable home.
Faster Construction
ICF walls go up very fast as they arrive as pre-made interlocking blocks – no framing is necessary!
They’re also conspicuously lightweight, and the foam forms remain perfectly in place post-pour, eliminating the need to remove a form.
That means we can finish roofing, utilities, drywall, etc., much faster.
Design Flexibility
These modular ICF blocks can be formed into any number of configurations.
Floor plans can be:
- Simple or complex
- Straight or curved
- Traditional or modern
ICFs give you full control to build exactly the home you want.
Peace of Mind
The use of ICF walls makes your home superior to fire and noise. Its fire- and noise-stopping, reinforced concrete core.
Homeowners have the peace of mind that they and their home are protected.
How Do Insulated Concrete Forms Work?
So let’s dive deeper into how you actually build with ICFs:
ICF Block Components
ICF blocks are two sections of expanded polystyrene foam held together by ties that can be plastic or steel.
The cross ties form the hollow cavities that fill with concrete.
ICF blocks stack both vertically and horizontally to create a solid frame for pouring concrete to create the walls.
Installation Process
There are four main steps to installing ICF walls:
- General layout – mark where the walls would go and the overall footprint
- Stacking – Lift-and-set ICF blocks to form the wall layout
- Reinforcement – These hollow cores will be filled with concrete and provide for inserting steel rebar.
- Pouring Concrete – The holes in the top of the ICFs are used to pump concrete into the cavities
When the concrete is cured, you have a solid monolithic ICF wall ready for interior/exterior finishes.
Integration with Structure
ICF walls integrate easily with:
- Footings – poured directly on concrete footings or stem walls
- Floors – adhesion to concrete slabs or wooden joists floors
- Connecting to traditional/inventive roof systems
- Code compliant – ICFs give you design flexibility.
Utilities
ICF walls readily accommodate electrical wiring and plumbing. Hollows are carved into the foam or are made by using removable inserts when the walls are stacked.
HVAC, electric, and plumbing can run in the foam or be surface mounted.
Finishes
ICFs are available in a range of interior and exterior finishes:
- Walls – drywall, paint, tile, wallpaper etc. Directly to the foam.
- Exteriors – stucco, brick, siding, stone – bond to the foam or require furring strips.
From an ICF wall, You have a blank canvas to paint your artistry!
Tips for Building with ICFs
Checklist for success with ICF construction: Planning and execution:
- Have detailed architectural plans that will guide the ICF layout.
- Spend time putting the first course straight and level
- Brace walls to hold them plumb until concrete has cured
- Use Vibrators to Properly Consolidate the Concrete
- If new to the method, consult with experienced ICF builders
- Comply with regional reinforced concrete building regulations
Take your time and review everything thoroughly, so that your ICF Project is up to par.
Green Insulated Concrete Form Projects We Offer
ICFs are not limited to new construction – they have sustainable advantages for any style of project:
Residential Homes
Most commonly, ICFs are used to build a home. Families love the comfortable, healthy, energy-efficient and quiet homes ICF walls created.
Commercial Buildings
ICF construction can be used to achieve green building certifications for schools, offices, retail spaces, etc. The cleanliness of the indoor air is valued by employees.
Additions and Retrofits
ICF additions and concrete overlays on current walls can make existing structures more durable. For owners, it means better insulation, and durability.
Storm Resilient Buildings
In hurricane and flood zones, the strength and water resistance of ICF makes them a perfect fit for buildings. Families have reliable shelter from severe weather.
Affordable Housing
ICF walls promote energy efficiency, reducing the cost of home ownership for low-income families by lowering heating/cooling costs. Certain affordable housing programs even encourage ICF construction.
ICFs provide an adaptable sustainable building solution with wide application.
Build a Sustainable Future with ICFs
I hope this post illustrated enough just how massive concrete’s environmental impact is and how ICFs are an environmentally friendly substitution.
The performance and sustainability benefits are obvious.
If this article makes you want to build your own sustainable concrete home, I strongly encourage you to visit the Eco Sustainable Home Designs homepage at ecosustainablehomedesigns.com.