OK...so in the previous post we made quite a bit of progress! It looks so easy, looking back at the photos from my comfortable chair.
Having backfilled the climate battery, I marked and excavated the rubble trench foundation. Having no experience with the excavator, I made a bit of a mess of it. Nothing fatal, but I definitely dug the trench too wide in some areas which resulted in having to fill afterwards using more gravel than necessary. The outer perimeter of the trench was insulated to R-20 using the GPS graphite-enhanced expanded polystyrene. Then I installed perforated pipe in the trench and filled it with gravel.
Next step was to build the gravel-filled earthbag stem wall. I can't overstate the labour intensiveness of this process. I have true respect for anyone who builds their whole house with earthbags. We filled, wheelbarrowed, set in place and tamped the earthbags, using approximately 20,000 kg of crushed rock. Since the earthbags are inside the insulated envelope, this is additional thermal mass. Using gravel ensures good drainage as opposed to soil filled bags.
We poured 3
concrete footings for the main support posts and installed the posts with bracing. By this time, my friend Angus was back to work full time at our regular place of employment so I had his help only on occasion for the heavier tasks. I began framing the south window wall, and the two side walls. With help, we got the main support beams up in, one piece at a time, and secured them in place.
The straw bales arrived in a shipping container, which was extremely handy to be able to work out of the dry container while building the walls. We did have an exceptionally dry spring.
After a layer of poly as a damp barrier over the earthbags, I began stacking the bales. This process went fairly quickly and was immensely satisfying. I have good memories of listening to the audiobook of "The Idiot" by Dostoyevsky during this time. Admittedly my inexperience in this field showed itself later, as some of the bale courses weren't perfectly aligned which resulted in some wavyness in the wall. Nothing too major however. I was concerned at first with how much the wall would sway and give, but I had read that the walls would stiffen up considerably once strapped down with the box beam (straps were installed under the first row of earthbags every 2')
In the last photo you can see the box beam installed and strapped down tight. I used a pallet strap type tightening tool, which ratchets the straps nice and tight. After this step the walls felt much more solid.
Ok, time for another photo dump!