Make cob by foot

Making cob by foot is really easy. If you have a tarp and spades that is preferable but not essential. Firstly get your sand and clay ready. A good cob is made from between 70-85% sand and 15-30% clay with long straw or other available fibre, and water. Mix you clay and sand together till…

How to fit frames to cob AFTER building the walls

If possible I would recommend building your window and door frames before starting your walls, that way you can build up to and around them and keep everything nice and flush. However with the construction method we are using at this site this was not posible for the doors at least. The windows can be…

Can you fit vents to a cob wall

Yes. And actually, if you have them ready whilst you are doing you final render you can push them in to the wall a bit to make them absolutely flush. Also make sure to tilt the vent forward a bit to make sure that any water landing on top will fall away from the wall…

How to make shelves and nooks in cob walls

It is very easy to make nice corner shelves and nooks in a cob house. For this corner shelf we had to stab in some wooden steaks whilst the cob was wet. The steaks are pushed downwards in to the wall at a 45 degree angle. These steaks then hold the cob mixture up. Try…

How to fit a 1st floor in a cob house

If you are planning on building a cob castle with two floors, then you need a few extra techniques to hold that 1st storey in place. Here is a simple step by step guide showing you what to do as you approach the top of your ground floor walls. First of all you are going…

Why use ‘Deadmen’ in Cob Walls

Deadmen is the word used to describe the naily pieces of wood used inside cob walls to hold a variety of things to the walls. When building a cob wall you are probably going to want to stab many holes in the wall as you build, in order for the wall to dry evenly and…

Test Your Cob Mix

So you have tested your earth to see the sand and clay content, now you are going to need to do some tests once you have made the cob mix itself. The recommended quantities of sand and clay in a good cob mix are as follows: 75-85% sand 15-25% clay Water Long straw The quantities…

How to Level your House

As you start building up from the foundations you are going to need to keep an eye on your levels. A floor that is two centimetres too high for example can mean a LOT of wasted material when that 2cm is translated across the whole house. You are going to need a ‘story pole’ which…

How To Build a Cob House

Here are the stages I have seen whilst building a cob house in Brazil Most bio construction I have learned has been through Eco Caminhos, Nova Friburgo. Some photos are from our first building, and some from the second so apologies for the discontinuity. Both were constructed using similar if not the same techniques Architects designs…

Making Your Cob Walls Smooth before the Final Render

So once you have built the structure of your cob castle, you are probably going to want to make the walls smooth so that you can effectively apply your final, more water resistent render. I have written a post already about how we made our water resistent render using cow poo. I am writing this…