This shed is constructed out of Rammed Earth and will have a Living Roof.
Additional Info: I first heard about rammed earth in January this year, it was used as an internal feature wall on a "Build an Eco House in 7 days" TV programme for Grand Designs. The house itself was primarily timber frame and straw bale, but this feature wall was amazing... I had to have a go!
The first rammed earth building I ever visited is this one! Here in the UK, the chances of you being able to visit a rammed earth building are slim... The Eden Project has a rammed earth visitor centre but that's a 6 hour drive for me.
I was motivated to build with rammed earth and not another building material because of the appearance of the finished walls. Then when I realised it was dirt cheap it became the cost. Now having single handedly rammed the walls I would say it's the connection with the earth as a building material... it can be quite a humbling experience at times.
I looked at how the Indian communities contructed single storey buildings and decided not to bother with any rebars. I have however added an additional "bond beam" between the roof joist to tie the roof joists together from each side of the 5 degree flat roof.
I used a "Soil Triangle Diagram" that I found on the internet to analise my own soil from the footings excavation by using a coffee jar full of water, and some of my earth. I found that I needed more clay silts so I imported 13 tons of sub soil from 6 miles away near the coast. I then used my invention "Sid the Soil Sieve" (see YouTube) to grade the earth down to 12mm. Once blended with 5%-8% cement I had the perfect stabilised soil for ramming.
This is a 66m2 building with a maximum height of 2.8m. The budget for the raised footings, additional earth, roof structure and the green roof is a mere ﾣ2,700.00 and I'm on track to achieve this budget. Notice that I am building a shed, not a dwelling, and so this was a project on a very tight budget... Pound Zero as I call it.
I am a Joiner by trade and work within the building industry, so I see a lot of waste and over-engineering. This shed is just a single story building, and so the need to spend a lot of time and money was not required in my opinion... time will tell if it stands the test of time!
It takes me about 3 hours to ram each section. Each coffin former holds 200mm X 2000mm X 500mm of rammed earth so based on that you could say that it would take 15 hours to ram 1 cubic meter by hand. My Eco-shed has 60m2 of walls so it should take me about 180 hours to ram. But you can double that twice over when you add in the sieving and mixing of the earth, setting up the formers and fighting the elements etc.
I didn't bother with the expense and extra work of insulation, the walls are too thin for starters (only 200mm or 8" thick) and this building is mainly going to be used as a garden kitchen and storage area. Also, where I am the weather is pretty good. We have the lowest rainfall in the UK and the winters are mild by comparison with the rest of the country.
After spending three months on research and many hours designing this building to the last detail... even making scale models - I think that I have got this pretty much nailed down. Maybe in a year or so I will see some areas for improvement, but so far I am more than happy with the results.
I have found that the whole experience has made me think a lot about rammed earth construction. So much so that I have decided to run some Rammed Earth building courses this summer... go to www.rammedearth.webs.com for more info. Sedums will occupy the green roof - they have been cultivated from soft cuttings.
Come and learn how to build with rammed earth at one of my weekend workshops this summer! www.rammedearth.webs.com
Cheers, Thomo. www.rammedearth.webs.com
You can follow the exploits of this sheddie's build here.
