Tuesday 25 August 2015

Ready to hammer-drill

       Our concrete is curing well, turning a very pale shade of white and starting to look like 'real' concrete. Once we hit the 2 week mark this coming Thursday then it should be basically finished curing, and we can start the next step. We need to drill some holes in the concrete, for which we are going to use a hammer-drill. In order to power the hammer-drill with electricity we will need to move the generator down to the house site, which is about 100m, or get a really long extension cord. Moving the generator will be tricky as it is fairly large and heavy, but we have a four-wheel trolley which we can use. Rolling it down the hill is certainly going to be easier than pulling it back up! Keep in mind that we don't have a car to make things like this easier, basically we are like the Amish but without horses!
       I have pulled out all the various bits and pieces supplied by the kit-home company, and gone through them and tried to work out what we are going to need first. The flooring is provided by a different company so there are no written instructions, only some pictures which we will hopefully be able to figure out what they mean. On top of the concrete we will first place a chunky plastic rectangle, then on top of that is a thick metal plate with uprights which the piers themselves will be placed over.

       A special kind of mechanical masonry anchor gets banged into the drilled holes, and then when the the nut is turned at the top, the upward pressure moves a particular part of it. This makes the part of the anchor that is at the bottom of the hole wider than the hole itself and so resists being pulled out. Sounds pretty clever to me!
       On top of the piers goes another heavy metal piece which has an adjustable screw. This means that if we need to change the height of the piers at any time in the future it should be quite easy. These screws are also good for preventing termite infestation, as a quick under-the-house check at any time after the house is built will let us know if any termites are building tunnels up into the house, and measures can be taken against them. This seems like much easier than the termite prevention that is required for a concrete slab, which involves poison, special mesh, great expense and harmful chemicals for humans and native habitats. Yet another reason why I am glad that we didn't get a concrete slab!
       23 concrete supports with 2 holes in each one = 46 holes which have to be hammer-drilled in exactly the right place.

Friday 14 August 2015

More Concrete

        We spent a lot of time coming up with ideas of what we could do with the extra concrete left-over from when we had the concrete truck come out and pour our footings holes. If you don't use all of the concrete that you order, then the concrete truck company charges a LOT of money, because they have to somehow dispose of it – and before it sets in the truck! So there were a lot of discussions of possibilities, but nothing that we could really agree on as definitely the best idea. We were both thinking that our own ideas were obviously superior, and the other person's ideas were a bit silly and unfeasible!So the afternoon before the truck came out we took advantage of the last half an hour of sunlight to walk down to the house site, and look around to decide what our best options were.
         Then Josh had the brilliant stroke of genius that we could grab the empty tyres that were sitting on the property when we bought it, and fill them with concrete. I think the previous owner was perhaps planning on building an Earthship at some stage, and that's why they had collected old tyres. I had seen a few other different uses for tyres too, such as using them as the corner supports for sheds, as the underneath base for a raised floor, or for heavy weights to use as a land anchor.
         So we used the last of the afternoon light to roll the tyres down the hill to the tank pad, as that is the only piece of ground which is level near the house site. Early the next morning I shovelled some sand into the wheelbarrow and wheeled it down to the tank pad, and made a little sand pad for each tyre. This was so that it would provide a roughly level base, and be easier to move after the concrete had set. Meanwhile Josh was giving the footings holes a final check to make sure they were ready for concrete, and building a little rock retaining wall around one of the holes which was in a bit of a hollow.


A few more minutes before the truck was due, I rushed up to the shed and grabbed some wood and some nails, and very quickly banged together a formwork. Just in time too – I carried it down to the house site just as the concrete truck was coming up the driveway. Josh was directing the truck where to back over to the footings holes, so I quickly jumped onto the other side of the house site and started shovelling a vaguely level spot for my formwork to go. It was at the spot where the stairs for the verandah will probably be going up, so hopefully it will provide a nice base for them to attach to. At the very least it will be a good spot to wipe our dirty feet before climbing up to our wooden floor while building the framework on our house!


 
         Then as the truck was moving over to this side of the house, I moved to a different spot and started shovelling another vaguely level area. I know what you are thinking – why didn't we do all of the prep work BEFORE the concrete arrived? Well, first we couldn't agree on what was the best plan of action, and then when it came to the crunch suddenly we were busy doing lots of other work during the week. That's the way life works sometimes!


Anyway, by the time the truck had finished filling all the footings holes, the step formwork, and the tyres, I had cleared a big enough area for a little shed. The last of the concrete in the truck was poured into the middle of this, and we roughly smoothed it out into a circular shape. Then we got a length of wood and pushed it over the slab a few times until it was about level.


         I am imagining this little slab to be the base of my cob hut that I am planning to make. We have plenty of clay on site which was dug out of the footings holes, so if I mix it with some sand and some hay or cow poo, then I should be able to build some cob walls. I am planning to embed the lower sections of wall with rocks, and the higher sections of walls with beer bottles. I am not sure how I am going to make the roof as yet, but I am open to suggestions! The rocks which I placed around the perimeter of the slab do not actually provide any structural function, but I went to all the trouble because I think it looks pretty.
         Overall the truck was on-site for about an hour and a half, though it felt like a lot less time since we were running around pretty busy and crazy for all of that time! I spent a couple more hours doing some smoothing of the concrete and cleaning up around the site afterwards, so it was a pretty big day. Josh had to go back to his computer work after the truck left, so it seems that there is no rest for the wicked :P

Thursday 13 August 2015

Concrete

     Yes - today the concrete truck came out, and filled our 'footings holes' full of lovely concrete. It hasn't rained for ages here, and so it was perfect timing as both the driveway and the holes were quite dry. All of our imagined fears and worries turned out to be unfounded, thankfully. The driver was a bit grumpy when he first arrived as he had been told to find the lot number instead of the Rural Area Number - which is a big difference out here in the country! Luckily he came around after he realised that everything was ok. We had no trouble with the truck getting over our dodgy grid, up our dodgy driveway, or backing down over our house site in order to reach all the holes. Then Josh directed the truck where to drive, and he and a neighbour who came over to help, controlled the concrete going into the holes. A bit of a swish with the special tool for the concrete chute, and a bit of levelling the concrete over the holes, and it was pretty much done. We did not need to add any reinforcing, we did not need to make sure the tops were perfectly level, and we did not need to put posts in the holes as they are going to be added later with dyna-bolts. Too easy!


     We over-ordered on the concrete deliberately, just in case it would not be enough - due to the holes filling with water a few times since being dug, so the size of the holes altogether was a bit difficult to exactly calculate. We would have originally needed about 2.2 cubic metres, so then if we over-calculated the hole size a little it would have been about 2.8 cubic metres, which could be rounded up to 3 cubic metres. But then we thought we would just round it up to 4 cubic metres, as then it gave us the opportunity to use the extra concrete for the same delivery price. Then we had to come up with a contingency plan for what to do with the left-over concrete!
     Our original idea of using it for the tank pad was poo-pooed by a couple of different people, who said we would be better off just having a sand base for the water tank. We had a few different ideas - some of which we came up with just before sunset the day before - and they all turned out to all be pretty damn good. I will update you with more info on these in a future chapter - stay tuned!