FAQ

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Frequently Asked Questions

Q: How does a timber framed conventional home compare to a stabilised rammed earth home?
A: Stabilised rammed earth homes are solid and contain the same ingredients as concrete but with lower amounts of water and cement. We refer to this as a drier mix. Most conventional homes are timber framed, the upfront cost of a timber framed home is 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 fibre 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 fibre 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 – Stabilised 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 fibre 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 harbour 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: 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. 

Q: Cold joints and shrinkage cracks, do they affect the structural integrity?
A: Rammed earth is imperfect, and some believe this is part of the beauty of it. 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 is the electrical system incorporated through 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. 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: 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 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 sq ft home it will take about a year.

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