Sunday, September 15, 2013

Our self build barn conversion/eco renovation

How it looked before we even started

 What an adventure a self build is, especially when it is part restoration, part eco renovation of a traditional slate barn where no human has previously lived and where no line is truly straight or parallel.
Not one right angle to be seen!

 Below is the design, more as a guide than an exact to scale design (due to the walls' undulation it was almost impossible to create a to scale design).
The design plan view: Shallow, gravel filled green roof with alpine plants and Mediterranean herbs
View from terrace above: The roof is built to be load bearing and can be accessed from the terrace, giving another place to sit and relax.

Green roof, eaves windows and green house on the front all help to keep the internal space comfortable year round
A cut through of the up stairs: Placement of rammed earth tyre stacks on which the roof rests and which are tied into the wall with threaded bar.  The roof beams are then bolted on top.  
Cut through of the downstairs. Cool air draft vent (closable) is located at the back of the inside room. The green house (with openable windows) creates a warm air source enabling temperature control though convection. Intelligent design and use of passive solar means very low energy needs and simple comfort.       

Side cut though.
Back cut though

Our progress so far...
The day we removed the old roof
Putting in the rammed tyre stacks. We cross braced  the walls with inch thick re-bar to secure them from moving where there was a bow in the wall. 
Completed stack, the threaded bars are cemented right through into the wall. These were filled with a mixture of clay, sand and cement poured onto lump hammer crushed slate in a layer cake formation, each tyre filled until fully rigid. We found later that using river gravel instead of the slate made things much faster.

Chestnut Main ridge beam and the rest of the wood is Nordic pine. All wood was spayed with Timbor borax and then painted with linseed oil for protection from fungus and insects.
Eaves beam being pinned in place, held on the theaded bar with large washers and nuts
The slow process of levelling the rafters, placed half a metre apart to make the roof load bearing 

 Roof is on! On top of the wood we put insulation sandwiched metal sheeting, with the ribs running across the roof horizontally, positioned slightly off level to take the water towards the terrace.

We had to raise the lintel of the door and rebuild the lintel of the window, both strenghened with an internal concrete beam and with a fascia of wood on the outsides 
Bales ready for the south wall infill
 Bottles ready in preparation for the cob bottle wall on the north side 

Finally we start to move away from the cement, and so can now get really mucky. Mixing the straw/clay slip to fill in between and glue the bales

All the bales needed tightening and we also treated them with borax to stop mould & insect invasion  

First level of bales in place on the sun ward side, with a layer of ferro-cement underneath which goes around the whole building on top of the stone walls acting as a ring beam and tying in to reinforce the walls and tyres. 

Last lot of cement on the chicken wire, topping off the walls, finishing our reinforced ring-beam.  

Second layer of bales going into place, notice the gaps, these were filled with part bails that were really hard to squeeze into place.

Cob mix tests to find the strongest consistency for constriction, going from 1/1 clay/sand to 1/2, 2/1 1/3 & 3/1. After giving them a week to dry, we found that the 3/1 gave the best strength and stability. This was because the soil that we were using was very clay rich.  

We took this opportunity to also make and dry out some seed balls, with the clay and some very rich compost that we had dug our of the downstairs of the barn. 
Cobbing in process, one side of the bales closed in.

Ferro-cement reinforcement for this leaning part of the wall

  So thats it so far
Hope you enjoyed
Keep tuning in here for further developments

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