“We wanted to seek alternative solutions that would solve the housing issues.” – Rueben Taipari/Heeni Hoterene – Whare Uku Rammed Earth Housing Specialists
Building a Whare Uku | Rammed Earth Home is labour intensive. Whanau commitment to hands-on mahi can cut construction costs by around 5-10%. However, building quality, low maintence homes from natural resources that last for generations is a proven way for family wealth to move forward.
“If you have everything in place – all your materials and your work crew, we can build two to three walls a day,” – Heeni
1: Test your soil – you must
Historically, the longest lasting Rammed Earth walls were made of soil that contained 70% sand and 30% clay. If you are building a home from natural resources, you have to know your whenua. There are a variety of tests* which can determine the suitability of your soil for construction.
*Tests can be performed at a Geotechnical Laboratory.
2: Preparing the site
Topsoil is removed from the building site and stored for re-use around the completed home. Soil is excavated to a depth that guarantees a level surface area. Organic matter is removed and composted for later use. The outline of the Home is staked out. The excavation includes the floor area of the building as well as a surrounding buffer zone. A trench is dug to incase all walls – anchoring them to the whenua.
3: Laying the foundation
Depending on the strength of the underlying soil, laying a foundation consists of a footing made from, in this case, reinforced concrete.
The footing is extended above ground level, connecting the rammed earth walls to the footing. A slab floor may also be poured depending upon your architectual design.
4: Framing the walls
Wooden forms are a major part of the process. It usually takes less time to fill and compact soil than it does to set, align, and remove forms. However – forms are, as one might guess, necessary for building walls.
Forms may shape the complete length of wall. Or shorter panels separated by gaps can be filled for enhanced structural strength.
5: Tamping the soil
Most Tampers are made from a heavy wooden block, with a handle extending upward through it’s center.
A kaimahi drops the Tamper from a height of 30-46cm/12-18in. After many repetitions over the entire surface layer, the noise made by the Tamper changes from a dull thud to a ringing sound. This indicates when the soil has been compacted to about half of its original volume. Another layer of prepared soil is added. The Tamping process is repeated. When Tamping is finished, the forms are removed. Pneumatic Tampers accomplish work quickly and manual devices are used in tight spaces. For example, around electrical boxes or plumbing pipes.
6: Finishing the walls
Untouched, rammed-earth walls have the colour and texture of natural earth. Moisture-impermeable finishes, such as cement render, are avoided because they impair the wall’s ability to desorb moisture, necessary to preserve its strength. Well-cured walls accept nails and screws easily, and can be effectively patched with the same material used to build them. Blemishes can be repaired using the soil mixture as a plaster and sanded smooth. The off-the-form finish gives a smoother surface and a more modern look, and the formwork lines and textural changes are more evident.
7: Roofing and Double Glazing
The roof is a Pacific gull wing light timber roof with exposed rafters, plywood diaphragms and coloursteel roofing. The earthen wall panels have vertical D12 reinforcing bars embedded within the earth to assist with resisting earthquake loads. “The materials are appropriate to use for construction because they represent the generative foundation for all life. All things are born from her and nurtured by her, including humankind.” – Principal Investigator, Dr. Kepa Morgan
Double glazed matapihi (windows) are the only way to go. For more information, contact us about Suppliers
8: Off Grid Options
There are many – we have worked with and seen alot more. For information – click here – (Self-Sufficency)
Rammed earth homes are comfortable using 80% less energy compared with wood-frame housing. Their thick walls regulate temperature and are breathable acting as filters, reducing airborne irritants in the home.
In colder months – “…the walls actually soak up heat… slowly releasing warmth over an extended period of time.” – Heeni
Rammed Earth Homes are fireproof, rot-resistant and virtually soundproof. Homes are custom designed and oriented to make the most of solar energy, water availibility and security. All contributing to a healthier home environment. Utilising whenua resources and local materials responsibily, connects people with their land, home and community.
“The sand [for our home] was sourced locally. The earth was from lands. Our muka fibre was harvested from harakeke (flax) planted by my husbands father.” – Heeni
“The majority of the time is spent waiting for everything to set, especially the foundations and the concrete ring beam that sits around the top of the walls. Even though the winter weather delayed us for more than 4 weeks, we finally finished the last wall today for the 2nd whare in the project. This whare is is going to be for my kaumatua and kuia dedicated to kaupapa maori and we are going to benefit from their knowledge of tikanga maori and matauranga maori to guide us in our policies for papakainga projects in the future” – Rueben