|Shoalhaven river sand
Not sure when the other deliveries would arrive, I started working on the formwork. The area I chose to start on was a small section between a sliding door and a control joint. The control joint is required above where I have a control joint in the concrete slab. Control joints were put in the slab at two weak points to prevent cracking by allowing any movement to take place in the flexible joint filler. This then needs to be followed up vertically in the walls above the joint in the slab. Like the slab I will cast the walls in two sections, using the left over joint filler from the slab in between. This small section had lots of studs, a door jamb and a corner in it making the formwork quite fiddly. In the very tight section we used boards only 45cm high as it looked like it would be difficult to tamp if the formwork was any higher. I used 55mm spacers cut from old conduit with 100mm hex head coach screws. I drilled a hole in the board for the screw then used an impact driver to put the screw into the studs.
In the meantime I phoned up to see where my hemp delivery was. I was assured that the delivery had been booked in, but at 2pm my hemp was still in the Hunter Valley. It appears that the transport company was having some difficulties. A few more phone calls throughout the afternoon and delivery was arranged for 7am Saturday. Sue from Ecofibre phoned me at 5.10pm to confirm that the transport company had picked up the hemp.
The afternoon was not wasted as I had also organised the Council inspection for the frame as I needed this done before I started covering it up with the hemp walling. The inspector arrived on time, looked at all the work, and the only changes I had to make were to add in two sections of diagonal metal strap bracing that had been specified by the engineer but not put on and to put a second nail in each piece of metal strap bracing where it crossed each stud. This was all dome and fixed before the binder arrived.
The truck carrying the binder worked past their usual 3pm knock off time to deliver my binder on Friday and it arrived at after 4pm. We had hoped that the truck could back up to the house and unload the pallets of binder onto the slab, unfortunately as the truck turned to reverse toward the house one of its front wheels came off the concrete driveway and almost got bogged in the soft ground beside the driveway. The truck only just managed to get out, leaving behind a trail of dirt and a big hole beside the driveway. The truck was not able to go off the concrete driveway, so the closest it could get was the end of the driveway. We had to move 5 tonnes of binder by hand.
|Lucky escape for the truck
|5 tonnes of binder waiting to be moved
I chose to use the Australian Hemp Masonry Company binder, as it comes premixed (easier when you are building a whole house), is made in Australia and has been well tested. We got the smaller 9kg bags of binder as we are using a 120 litre pan mixer, rather than a 300 litre mixer that can use 18kg bags. Klara from the Australian Hemp Masonry Company has also provided me with support getting Council approval and with building questions I have had.
|Bag of binder
|One pallet moved, four to go
Matt the driver spotted a forklift working at the hardware store about 200m down the road, so I went down and asked if we could hire the forklift and driver for a short while. Unfortunately the forklift was not able to go off the premises, but JP at Culburra Beach Home Hardware did loan me his pallet jack, which turned out to be our saviour. Matt rolled each bale off the truck and it landed on one side on the pallet jack, we then took each bale up to the end of the concrete driveway. We could not leave the bales at the front of the driveway as we share it with the people who own the house in front of us. Once we go the the end of the driveway or where the bales had filled up to we just lowered the pallet jack and pulled the bales back upright and off the jack. The driveway was damp and very muddy from the truck that nearly got bogged the day before and the bales filled the whole of our section of the driveway.
|The hemp truck unloads
|Bale moving part one completed
|Temporary road and ramp
|Bales all safely moved into the house
The Aardwolf pan mixer was beautifully quiet when we tested it empty. The question was whether it would be as quiet with a full load - it was. We added water, hemp, a bit more water, binder, then once it was well mixed, 8.5kg of sand. We added the water a bit at a time, until the mix looked and felt right, but will work of getting a more accurate water measure, bearing in mind that the amount of water will vary with the conditions. We wore gloves, dust masks and eye protection. With the binder in small bags it was easy to lift over the mixer and pour in slowly and this kept the dust down.
We got the mix out into flexible buckets, that could be shaped into a spout like shape to pour the hemp into the formwork, although in the narrower sections we put the hemp in by hand, which was quite inefficient. We will try and manufacture a scoop from a plastic milk container like they did at the Billen Cliffs house. The smaller tamper we had made worked well getting around the studs, even this was not small enough for some sections and we resorted to using using pieces of timber on end. Tamping down into the step down in the concrete and around the damp proof course was difficult and where a narrower tamper will be useful. The location of some of the spacers also made it difficult to tamp. The work was not heavy and we did two mixes making a wall about 45cm high.
|The hemp looks like playground mulch
|Test wall section
|Test hemp wall
|Spacer too close to edge to tamp
|A beautiful hemp wall