Material Guide: Rammed Earth
What is rammed earth?
Rammed earth is a material that can be used to construct the walls of your home.
Rammed earth walls are made in situ (on site) by ramming together a mixture of sand, gravel, silt and clay using formwork to create the shape of the wall.
Advantages of using rammed earth include:
Rammed earth provides great thermal mass. This means that it has the ability to absorb heat and release it slowly, helping to regulate the temperature of your home.
Generally rammed earth has low embodied energy, although the cement content and transport requirements need to be considered.
It looks great and can be a stunning design element, both inside and out.
It provides good sound insulation and creates a nice acoustic atmosphere.
Rammed earth is durable and will stand the test of time, lengthening the lifespan of your home and reducing the need for maintenance.
What is Thermal Mass?
Thermal mass refers to a material’s ability to absorb heat and release it at a slower rate.
In winter, thermal mass can absorb heat from direct sunlight and slowly release it to act as a passive heater.
In summer, it can absorb ambient heat in the home and release the heat overnight when cooling breezes can vent it out.
Important considerations:
Rammed earth provides limited insulation so in some instances you may require further insulation to be installed.
Rammed earth walls are thick, ranging from 300mm to 500mm in thickness, and space is needed to construct them. This means they are not the ideal material for a tight inner city site.
There are limitations in the forms that can be created from rammed earth so the material lends itself towards simple structures.
You need to plan ahead with your services and their locations to avoid damage to the rammed earth.
Needs protection from rain
The cost of a rammed earth wall can be higher than other wall systems
Should you use rammed earth in your sustainable home?
Absolutely, if you have the space and budget for rammed earth walls then they can be a great option for minimising your environmental impact and controlling the temperature of your home.
What do you want to know about sustainable design? Ask us