The Foundation
A successful earth construction project starts with proper foundations. The rammed earth walls need to be placed and supported upon engineered concrete footings. Vertical reinforcing steel extends from these footings through the earth wall into the bond beam at the top of the wall. Conventional concrete slab or strip footings are generally used, the size and shape of which is subject to soil conditions.

Form Setting
The custom form work is then placed and secured in sections ready for the earth. This requires plywood sheets, timber planks and concrete construction bolts not too dissimilar to in-situ concrete construction but with its own specific requirements.

Adding the Earth
Desired soil is tested for suitability, mixed with approximately 7-10% cement and then placed and compacted into the formwork in layers of between 150mm and 200mm deep. Using a pneumatic rammer the soil is pounded down to approximately 5/8ths of the loose height of the material. Walls are rammed in layers of approximately 100mm. The form work is removed immediately after compacting to reveal the finished surface of the walls. Once all the walls have been completed a concrete bond beam is cast, linking the top of the walls together.

Joints and Connections
Walls are built in panels of approximately 2 metres in length. When a wall consists of more than one panel a rebate is built into the end of the first wall. The second wall then moulds into this to lock the walls together for lateral stability.

Timber Framing and Finish Work
Once the earth walls and concrete work are completed, the timber-framing phase of the project begins. This includes roof, some interior walls and mid floor framing if suspended concrete slabs are not used.

Fixings
Most conventional masonry fixings work with rammed earth walls and they usually need to be set in at about twice the depth normally used for concrete.

Openings
Openings can be made without lintels with spans of up to 2 metres in stabilised walls (subject to strength and engineering requirements). Specialised formwork can be made to make features like arches, reliefs, stencils and curved walls and the formwork can often be reused.

Finishes
The off-form finish of stabilised rammed earth generally requires no additional finish. Rammed earth should be protected by eaves, overhangs or a breathing type sealer. Walls can be surface textured to create different finishes. They can also be very easily rendered, plastered or painted.