Drainage

A couple of things have had me pondering drainage lately.  When I dug the grave for Rob Anybody I was happy to  notice that the soil around here is full of clay - great for building with cob!  The other thing is that it has rained a lot here lately.  First it snowed, now it is raining.  Road closing amounts of rain.  The Huon River is swollen and running fast.  The combination of clay soil and huge amounts of water is basically sodden, puddly, water-not-going away ness.  For a cob house this is not good!

There are a couple of things I can (and will obviously) do to prevent the water damaging my house.  Good drainage in my foundations is one of them.  I plan to dig a deep foundation trench, lay gravel, ag pipe, more gravel then larger rocks and then the foundation.  I'll slope the trench so that it follows the natural downhill of the slope and runs into the creek that borders the  property.
I will also probably dig some french drains further up hill of the house to guide the water away from the house and to a more useful place.  I'll try and build the house as high on the block as I can , but also don't want it too close to the road so there will be a balancing act there. 

Another vital part of it will be making sure the stem wall - the part of the foundation that is above ground level and forms the "boots" of the building - is high enough that any water splashing off the ground doesn't get the cob.  I will also include a damp layer in the foundations to stop rising damp.  I will have eaves that extend a good way out from the walls too - generally a standard feature of Australian houses any way - and will be collecting rain water for drinking so any splashing from water off the roof will be minimal. 

The clay soil, while being great for building a house, will also be crap for the garden.  It will need lots of compost and aerating for it to easy to grow anything.  The Lancre Witch has suggested that we slash the grass (which is currently about waist high) and leave on the ground as mulch and do that over the next few years as the building process gets going so that the as the grass breaks down it is nourishing the ground underneath.