July has been a busy month! In between two long courses, the first Natural Building with Jorge Belanko and the second a Bio-Architecture course there has been a lot of progress on the house on the hill.
All the ‘cascajes’ (60) have now been laid making up the roof slab, getting ready for the ‘intensive’ green roof. These have been painted underneath with a layer of limewash so as to take the earth plaster later more easily. Cascajes are an arched form using the minimal amount of concrete to gain maximum efficiency and strength. They use around 1 bag of cement for 6m2 of slab area – see the ‘Cascaje’ page if you would like to download the plans to make your own.
Once they are put in place they need to be tied in to each other and the ring beam itself. For this we put a layer of strong cement and add some extra re-bar (light gauge) and then some bamboo and rubble to fill up the valley, with some extra weak soil-cement poured over the top which is mixed with asphalt for waterproofing.
There have been skylights added to smaller areas (holes cut directly into the cascaje) and the idea later is to add large glass bottles (bottom down, filled with water) which will act as natural lightbubs and concentrate the light. Originally the ensuite bathroom in Peter’s atelier was to be open to the sky but since rainfall can be quite heavy it was decided finally to enclose it.
Many notches have been taken out of the surrounding window and door frames which will be filled with a mixture of mud and nails to provide nailing plates in which to support the timber frames later.
A lot of progress has been made with the layers of earth plaster; all walls are now ready to take the final coat. We have started this final layer in Peter and Vero’s bedroom, using a ratio we learnt in Jorge Belanko’s course, and have added some cow manure for extra strength. It looks great, is very strong, and would be fine to leave this now as finished except that the idea is to have white walls for most of the rooms. We have located an off-white clay in a nearby fazenda and will be making a paint from this.
An extra skin has been added on the south wall behind Peter’s studio using a pau-a-pique technique we learnt in the Belanko course (fibre-rich) to prevent heat loss in the colder months.
An arched adobe form is about to start being built over the entrance-way. The form is up and waiting for the bricks to be put in place – we just need to finish locking in the adjoining cascajes….nearly there!