The Rains have come!!!

The rainy season usually starts in October/November and in this region it is desperately needed and awaited by both people and wildlife. This year significant rains only started in mid January. The plot and the bush around are now looking green and lush.

So with these rains we have paused construction until the end of March, we need to allow the cob to dry during construction, I will continue blogging about ideas, design and any developments during this time.

                            Wild coffee bean Bauhinia Petersiana growing on the plot

Design

This is the basic floor plan for the house, it is 10 meters diameter. It took a long time to decide on the size, we spent many sunday afternoons drawing the design in the sand and putting furniture inside to have an idea of space. We wanted something small and cosy, but not too cramped, so it has 2 bedrooms, a kitchen and living/dining area. We will have a compost toilet which we wanted outside but with our 3 year old we decided to have a toilet inside with a basic compost toilet design which will not have the chamber built in but a bucket which is emptied onto a compost pile. The external walls of the house will be 50 cm wide and internal walls 25 cm wide. There will be a mezzanine above the bedrooms, to use the  space which is created by the thatched roof.

We also want to create outdoor living spaces as we spend a lot of time outside having spaces to sit and relax outside are as much a part of the home as indoor space. All the windows will be rounded and arched, some will be glass panes built into the wall, as well as glass bottles into the wall. The nice thing about cob that I'm looking forward too is adding sculptural details, alcoves, shelves, gecko shaped windows etc.

The roof will be gum-poles and thatch all of which are sourced locally, there will need to be a central support for the roof otherwise I like the idea of a reciprocal roof design but not sure how possible this is with thatch when a minimum 45 degree angle is needed, anyone who has any information on this I would be interested to hear!

Termites the original mud builders!!

Termites are amazing little creatures, when I first moved to Zimbabwe I was amazed to see these mounds that appeared all over the horizon, sculptural and intricate in their own right, these are the original mud builders!! In areas where no clay is found people building mud huts in zimbabwe will use the termite mounds by grinding it up and adding water, then making bricks from this, the result is very strong. I chose not to use this method as I would prefer not to destroy termites homes, after all of that hard work! Unfortunately when building your own home termites can become a huge problem, eating through structural wood. I really don't want to use any harmful chemicals for treating the wood, here the only options are pressure treated poles with Cresote or CCA. I would like to treat wood myself with something less harmful such as borax.

I have had some good suggestions, help and advice from joining a permaculture forum http://www.permies.com , which includes a natural building forum, there are lots of interesting ideas and topics raised. I posted a link to my blog to see if anyone could help and a discussion on termites and wood borers has started up, please have a look if you are interested or have any ideas http://www.permies.com/t/11974/green-building/cob-blog-please-have-look

Details, details...

I drew up the design for this door, which will be the front door. A local carpenter who uses wood from the forestry commission, which is the most sustainable source of wood here at the moment. The wood used is Mukwa. He did a great job, I'm really happy with this, a window pane will be fitted in the circular hole. I love arches and I am keen to have mainly arched doors and doorways in the house, this also reduces the need for lintels. The back door will be rectangular with a lintel as I have some old railway sleepers which look beautiful as lintels.

Any wood which is cut and used in the house, we are replacing by planting more trees which I have grown from seed on our land.

Laying the foundations.

For the foundations we have been using stones which were collected close to the land with a scotch cart. The stones vary in size and shape, larger heavier stones were used for the first layer. Over lapping is as important as in brick work, to ensure no continuous cracks form.

The mortar used between the rocks is the same as the cob mix, but with 15 percent lime added. So to mix this we needed to wear boots as lime is very corrosive. The lime hardens the mortar.

There is no bore hole on the land, so I delivered water each day emptying it into an old bath.

Site selected, marked and pegged, get digging!

The site was selected, Misheck pegged out the building according to the design I had drawn up (which I will post soon!) and we were ready to start digging. It's quite a huge job, I wanted to make the foundations 1m deep and 60 cms wide to make sure the weight of the roof could be supported by the walls.

It's great to start seeing the shape and design come to life! The sand that is dug out of the foundations will be used in the cob mix.

Now the foundations have been dug, the earth below is rammed to compact the earth below.

I've included the site of our future home on the 'Location' link below for you to have a look!

Getting started

We bought a wooden shed to store all the tools and materials whilst we are building. I made a stone floor with a cob/lime mortar. It gave me a chance to see how strong the mix with the lime was.

For digging and building the foundations for the house we decided to employ a local builder and 2 helpers, to dig the foundations ourselves would take a long time and we wanted the foundations done before the rains start! Once the foundations are done, I plan to build the cob walls myself.

Looking at possible sites to build with Misheck who will be building the foundations

Yabani delivering rocks from nearby in his scotch cart

Clearing the site, we chose an area where we didn't need to cut down any trees, with a good view, drainage is good, we then cleared a road going around any large trees to have access to the site.