So much has been said about the environmental and cost benefits of rammed earth structures but many are still concerned about a number of things regarding stability and about how true the benefit claims are. If you’re considering a rammed earth design for your home, it’s vital that you conduct your own research first before choosing the builders to entrust the task with and determining the structural design you want for your home.
Normally, for rammed earth walls you would have to make sure that the typical materials used for construction are not compromised with the inclusion of conventional building materials like cement. Studies reveal that when cement is used in the earth mixture, all the sustainable benefits such as humidity control and low embodied energy will not be achieved. While there are further studies aimed at addressing the sustainability issue raised by the inclusion of cement in the traditional earth mixture for rammed earth construction, expert builders utilising this technique prefer to use the traditional composition, believing it would be irresponsible to integrate cement into the mixture since it would require the exclusion of clay, and therefore the integrity of the material will no longer be preserved. Also, if you’re choosing rammed earth construction as a way to uphold an environmentally conscious lifestyle, you should definitely rule out cement because it emits high levels of carbon dioxide, and mixing and disposing of it is a highly toxic process.
Also, take into consideration the height of the windows and doors. Builders suggest making the openings full height as this can minimise costs; every time a rammed earth wall runs over the top part of a window or door, they need to use a steel linter which is quite expensive and also makes construction longer and more complex to accomplish.
It’s worth taking note of the predominant climate of your area as well for this will allow you to determine what other treatments you will want applied on your walls to make them more durable against rain and other weather elements. Earth can be dry-lined or sheathed, painted, plastered, rendered and sealed. If you live in a relatively dry area, maintaining the natural finish and colour of the earth mixture will not be that big of an issue and can bring forth cost benefits. In addition to this, you may want to look into your choice of roofing materials and design because, like other masonry products, the earth mixture for rammed earth lasts longer if properly kept dry.