Rammed Earth Building is both evolution and revolution. Its origins date back ten thousand years.
Stabilised rammed earth is a strong and durable construction method, is weather resistant, thermally efficient and maintenance free.
Stabilised earth construction is solid and natural from the ground up.Earth building materials costs are 'dirt cheap', often an important consideration for owner builders. Although it is based on a ten thousand year old tradition, stabilised earth inspires non-traditional contemporary thinking.
This is because it is a medium which invites individual expression.
While it also combines well with conventional building materials, it is a plausible alternative in its own right. So the possibilities are endless....Rammed earth, stabilised earth, nouveau-pise, new terminology for a building technique that has stood the test of time.
Formwork
Corner Form
Set in place & ready to take the first layer of earth.
Note the tall vertical form at left, which will be left in place for all three horizontal layers that bring the wall to ceiling height. This vertical form has a key way attached that allows the form sections either side to join.The inside faces of forms were painted with vege oil as a release agent.Lengths of reinforcing rod can be seen protruding from within the form. With each new form, rio-rods were welded on to extend up through the wall sections. A final length of threaded rod is welded & protrudes above the wall enabling the roofing plate/beam to be bolted down.
This corner form will produce a wall 450mm thick & requiring over one tonne of earth. Building codes for one storey houses only require 300mm thick walls. My heavier gauge walls really increase the insular cosiness inside, especially during extreme weather.
This home weighs over 80 tonnes but the standard cement slab only required some extra steel re-inforcing rod, luckily I am blessed with a good ground rock base.
Hand Ramming Begins
Coffin Form
Ramming an upper section of wall in the coffin form. Notice how the coffin form is clamped onto the already rammed corner. Corners of walls are the starting points, other sections follow on. Adding further sections to the structure may take place as soon as one can reset the form, there is no drying time required. Threaded rods clamp the form together, along with furniture clamps where the coffin form overlaps the outer faces of the earth wall. Two threaded rods holding the two sides of the timber form together at the base become earth-rammed in place and need to be unscrewed from the just completed earth-wall section. This is done by locking two nuts at rod end then simply unwinding.Use of a high torque electric reversing drill is recommended.
Australias Heritage
Rammed Earth Houses
In Albany, Western Australia, the oldest rammed earth building is Strawberry Hill Farm built in 1830, rammed by hand with no cement added.
This farmhouse remains perfectly sound and is classifed by the National Trust.A fine example of rammed earth's durability.
N.B. "Strawberry Hill" had NO added Cement Stabilisation as todays R.E. buildings do. Some pioneers used an earth ad-mixture from termite mounds which added a binding medium to the earth. The termites masticate the earth with a saliva agent that makes their mounds tough & resiliant to weathering
Corbled Brickwork
Rammed Earth, probably the most sustainable form of wall construction, requires minimal energy consumption in the process compared with alternatives.
No fossil fuel consumption, as in baking bricks.
No processing of artificial materials or added paper as in Gyprock & Chipboard.
Minimal use or milling of timber.
Minimal use of expensive Portland Cement and associated limestone mining.
Further no "sick building syndrome" gasses emitted as with man made building products.
Rammed Earth has a high load bearing compression capacity compared with other methods of earth building.
Winching third floor beam into position
The aesthetics of rammed earth create an incomparably warm natural ambience.
All things considered, no other material meets the requirements to the extent of rammed earth.Structurally with 45cm walls, I may have added further storeys to the building with the high load bearing potential.
Because the only finish, interior/exterior required is a one off spray with "Bondcrete" or a commercial silicon product for exposed walls, overall maintenance is minimal!
Plus the added advantage of constructing the walls directly from the raw material means no brick laying.
House bricks are enormous consumers of energy in forming,firing and cartage to retailer then to the home site.
Rafters Up
~ owner builder cost effective
~ virtually maintenance free
~ planet earth friendly
~ load bearing
~ fire proof
~ termite proof
~ in-situ construction
~ highly cyclone resistant
~ healthy living environment
Pensioners track.
Construction of the two storey, 45 cm. thick walls took place part time over an 18 month period.
The walls were hand rammed within light-weight and easy to handle wooden forms made of 19mm or 3/4in flooring ply and pine studs, comprising a corner form and coffin form.
Hand ramming has given the walls a high grade of compaction. Disappointingly some commercial builders of R.E. with financial & time pressures are not acheiving good grades of earth compaction, often adding much more than the correct standard benchmark of 100mm (4 inches) of loose earth layers to forms before each compaction.
This errant sub-standard practice is devaluing Rammed Earths reputation!
Railway sleepers were used for door and window jambs/ lintels. The rail sleepers were incorporated into the earth forms and mechanically attached to the earth wall sections, they also assisted the follow-on upward forms to be set.
The earth I used is a low grade bricklayers loam light yellow in colour & was trucked to my site.
Light coloured Earth was intentionally chosen to keep a light reflective ambience inside the house.
Deformed reinforcing rod is incorporated vertically throughout the structure.
The steel rio-rod is anchored to the cement slab foundation and is tied off at the roof plate making the walls and roof of the house highly cyclone resistant!Stable second hand massive hardwood beams were used for the roof plates and internal spans.
Ground floor facing south
Passive Solar Design:
Consideration of passive solar design in building is of critical importance in the climate of global warming.
We are all individually responsible for minimalising energy consumption, where better to begin but in our homes where the majority of our time is spent. It is also to our longer term financial advantage to lessen energy costs & our future childrens wellbeing on a healthy planet.
Orientation awareness of your building block is essential to your plans.
The North and solar facing front of the this building is fitted with hi-tech solar guard glass, which eliminates 85% ingress of solar heat during the day but retains warmth at night.
Ground Floor photo above shows the south facing windows, when opened, allow cooling breezes to flow through the upper floor in summer.
In Australia & southern hemisphere sunlight & warmth come from the north, this needs to be the first consideration when planning & orientating your intended home.
Air and light well
An internal air and light well ensures warming of the whole house in winter and permits a cooling airflow in summer.
The conscious passive solar design applied, made the building energy efficient.
Cantilevered verandahs are incorporated around the second floor. To allow verandah joists through the rammed earth walls corbled brick work was used.Over 80% of the building work was completed by myself. I had help to lay the concrete slab and to raise the roof.
The challenge of lifting large beams into place was basically performed by Tirfor Winch, bamboo tripods & brain cells. Standing the two five metre 22cm x 45cm hardwood beams at the north glassed face was memorable.My home is situated on an exposed ridge top in west Byron Shire (Northern NSW), with a view of the Border Ranges and Queensland. Here the wind and most-times horizontal rain, can reach extreme levels. June 2005, over 20 inches (500 millimetres) of rain recorded here in three days.
Mature hardwood forest around the house's perimeter presents an extra hazard. A tropical low pressure cell in 1984 felled a tree top on a temporary dwelling, admittedly this particular tree had previously been hit by lightning.
Living here requires a certain "mountain man" mind set. Thus the over engineering of the structure, especially the rammed walls, provide a protective comfort zone of tranquility and safety in both serene and extreme weather!
This building has now been withstanding the elements for over fifteen years! As maintenance goes, little has been done.
Some repainting to the exterior woodwork. The earth walls are showing no weathering and I can only conclude that this structure will be here long after I shuffle off this mortal coil.
The promotion of sustainable, low cost & energy effecient housing is I believe a most important cause in the use of finite natural recources on over populated planet EARTH.
I have carefully observed rammed earth structures around Australia and collated information from varied scources. Subsequently I built the necessary formwork and constructed this home and had hands-on experience with other rammed earth projects.I am available to consult with any owner builder intending to create a rammed earth home.
Please contact me at the email address below for assistance in your Rammed Earth project.
Frogmouth Owl visitor.
Rogers Rammed Earth..... this web-site also
handbuilt and updated by Roger G.
March 2009
