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Frequently Asked Questions

Q: What is Stabilized Rammed Earth?
A: Stabilized Rammed Earth is a masonry product. The typical wall is largely composed of aggregate from a quarry; manufactured/crusher fines blended with 3/4″ road crush, 8-10% cement and a small amount of water. The wall system is reinforced with re-bar and formed very similar to a concrete wall.

Q: What is the average cost of Innovative Earths custom Rammed Earth homes?
A:
Our cost is comparable to custom stick framed homes. Thanks to the development and improvement of our mechanical construction systems, we can now offer certified passive rammed earth homes at $250-$350/sqft! Here’s to a future of affordable,
healthy and resilient homes in Canada!

Q: How does a timber framed conventional home compare to a stabilized rammed earth home?
A: Stabilized rammed earth homes are above and beyond the structural standards of a conventional residential home. Most conventional homes are timber framed, the upfront cost of a timber framed home can be more affordable but the costs over time will increase. Some examples of how rammed earth homes save you more money over time are:

  • High thermal mass – This creates a more regulated indoor temperature and leads to cost savings over time. It is a higher insulator than timber.
  • No thermal drifts – In a conventional home, there is loss of R-value due to fiber insulation slumping over time. EPS and XPS insulation is used in our rammed earth homes. EPS and XPS does not slump over time, this maintains the R-value for many years, longer than a conventional home, this leads to cost savings over time.
  • Air movement – Conventional homes are not air tight. There are holes in exterior siding that allow air to be sucked inside of the home. Air movement within the walls and attics and around insulation decreases the R-value of fiber insulation. Rammed earth provides an air tight exterior wall, and there are no chances of air-movement within the wall system, this also leads to more cost savings over time.
  • Resiliency – Stabilized rammed earth homes will never need to be demolished for centuries to come. These homes are resilient to extreme weather (floods, tornadoes, hurricanes, etc.) and will need minimal restoration compared to a conventional home after a disaster strikes. If a flood happens within your rammed earth home the water will not (or minimally) penetrate the rammed earth walls and insulation is not affected. Water affects fiber insulation in a conventional home but XPS and EPS will not be affected if water does happen to touch it. Rammed earth prevents any mold growth, as there is no cavity for it to grow and XPS/EPS insulation does not harbor mold growth.

Q: What is thermal mass?
A: Thermal mass refers to the structures ability to slowly absorb ambient heat, store it then radiate this heat. It can help regulate indoor temperatures and lead to energy savings. Thermal mass is not considered in R-value testing and can strongly influence the performance of insulation and reduce energy consumption. Our rammed earth wall system has a high thermal mass rating; energy modelling and energy performance tests prove this.

Q: How is the electrical system incorporated within Rammed Earth?
A: The electrical is ran through conduit that is embedded in the rammed earth during the building process. The electrical box’s are also installed as the wall is being constructed. 

 

Q: Insulation for Rammed Earth?
A: Because of the frigid winters and the building codes in Canada and parts of the US, insulation is installed and embedded within the rammed earth wall. There are many types of insulation that can be used such as a rigid foam-based product, or high density ROXUL. The typical average R-Value of a Rammed Earth wall is between R22 and R30, depending on the types and thickness of insulation.

Q: What is R-value?
A: R-value is the measure of thermal resistance. The higher the R-value, the higher resistance it has to heat flow.

 

Q: What is XPS or EPS insulation?
A: XPS and EPS are polystyrene insulation products. XPS stands for Extruded Polystyrene Insulation and EPS stands for Expanded Poly Styrene Insulation.

 

Q: Does the environment have any structural effects on Rammed Earth?
A: Rammed earth homes have been built in a climate that endures up to -50 degree Celsius winters. Walls have not shown or resulted in any cracking due to these harsh environmental effects. Rammed earth is also very resilient in wild fire conditions.  Rammed earth is actually particularly suitable for damp coastal regions of the planet. Certified passive homes need to have an HRV/ERV (Heat Recovery Ventilation or Energy Recovery Ventilation unit) installed within. This provides ample ventilation for healthier air. The walls provide no void space or material for mold to grow, so there is no chance for mold to effect your family! Oh and water actually strengthens stabilized rammed earth walls.

Q: Cold joints and shrinkage cracks, do they affect the structural integrity?
A: Rammed earth is imperfect, and some believe this is what makes it so beautiful. Some visual imperfections may include shrinkage cracking and cold joints. Shrinkage cracks are non-structural and are part of the curing process; as rammed earth cures, moisture evaporates from the walls causing them to shrink and slightly crack. Some people may notice cold joints in the product and may mistake it for a structural deformity. Cold joints form when the lower portion of the wall is finished and must cure for a length of time. After the lower section of the wall is cured and the construction is commenced for the next section (above the cured section), a cold joint can be seen between the two sections. This joint is not a structural deformity and does not effect the integrity of the product.

Q: How thick are the Rammed Earth Walls?
A: Insulated rammed earth walls are typically 18 inches thick. Depending on the application or product, the walls can vary from 4 inches to 24 inches thick.

Q: What’s the difference between Rammed Earth and ICF?
A: ICF is a concrete forming system which requires finishing on the exterior and interior of the walls. ICF results in the on-going maintenance that comes with whatever interior and exterior finishing products used. Rammed Earth has no maintenance once completed and does not endure any damage resulting from the environment.

Q: How long does Rammed Earth take to complete?
A: This all depends on the project size, location and difficulty. For an average 1200-2000 square foot home it will take about a year.

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