Wednesday, September 9, 2009

Thursday 22nd Jan 2009

Slab Poured!

Well a few weeks turned into a few months. We had a lot of pre slab organising to do and a few visitors thrown into the mix so sit tight and Ill try and fill you in without rambling too muchJ

In preparation for laying the slab we had to employ our first outside contractor for the under-slab plumbing. Bernt and I measured where all of the drains needed to go and slowly dug the trenches. It was really tough work digging in the hard clay, especially when we had to dig through the area where we had previously mixed concrete. Didn’t realise the impact washing down the cement mixer would have on the soil below. It had set rock hard to a depth of 20cm or so. This wasn’t to be the end of our digging spree. We also had to dig a 30m trench along the south side of the shed, I say ‘we’ very roughly. Bernt did the lion’s share of the digging, he is a machine!  In that trench we laid pipe to eventually connect the down pipes to a water tank as well as an agricultural drain to stop water from flowing down the slope and under the slab.

The Plumber and his assistant came in on the 28th Oct and worked very efficiently, laying all of the under-slab pipes in 2 hours. We next took delivery of all of the in-slab infrastructure; steel mesh, reinforcing rods etc etc as well as the 150 polystyrene ‘pods’ which the slab would be poured over and around. These pods are about a metre square and 225mm thick and as they are made of such a lightweight material we had to build a huge cage from the steel mesh to house them until we were to lay them, lest they blew away. So Bernt and I built a cage. Such a silly undertaking, we could have killed ourselves. The sheets of mesh are 6m by 2.4m and so heavy that we could barely lift them with just the two of us. None the less we needed to build this cage and only had the one evening to do it before the pods arrived. The sides were fairly straight forward but lifting 2 sheets for the roof and holding them above our heads while they were tied in place nearly killed us both. Copious swearing that evening!

 

 The cage we built to house the polystyrene pods.

We had a few things to do to finish off the retaining wall, namely waterproofing it to stop rising damp from entering the slab. Most probably over the top, our engineer had specified that we both paint it with a bituminous tanking layer as well as lining it with a plastic sheeting. Not hard jobs. Then we installed another agricultural drain to remove any moisture build-up that may happen underslab and backfilled with fine crushed rock (more digging). We then lined the front of the retaining wall with more polystyrene in the form of sheets with a rendered side. These form a part of our uber-insualtion plan but we also used the over hang at the top to form part of the ‘boxing’ which would hold in the concrete for the eventual slab pour. We then had piles and piles of fine crushed rock delivered to spread out under the slab. This was in early November and was where we stopped for a while, only really getting back into the swing of things after Christmas.

In the mean time we had lots of exciting non build related things happening! My mum and Craig came to stay for a couple of weeks, we got ourselves a gorgeous little puppy (now a bit of a terror toddler), Bernt’s brother Felix and his friend Rosalba stayed for a week, at the same time Millie (who I used to baby-sit a millennia ago) and her boyfriend Jeremy came for a weekend. And so we had lots of catching up and a bit of sightseeing to do with all. We did have our water tank delivered during this time. Most beautiful water tank you’ve ever seen! It’s the colour that our roof will eventually be. 98000Litre capacity which makes all of the locals who see it laugh because they’ve never seen anything that big and are sceptical that we’ll ever fill it. One even called it a reservoir! We also had a go at putting the first coat of render onto the retaining wall (over the insulation). It wasn’t a complete success, I think it dried a bit too quickly but it was good to have a practice in a spot which will be hidden by veranda. We have had heaps of tips about how to improve for next time.

Over this break in proceedings our piles of fine crushed rock sat unattended on our shed site, slowly hardening in the rain and sunshine until they developed a thick crust impenetrable by our shovels. So we enlisted the help of our neighbour and his trusty tractor to help flatten the piles for us. He came just after Christmas and we spent Bernt’s 2 week Christmas break hard at work preparing for the slab. More digging, again Bernt doing most of the hard physical work. We worked on getting the fine crushed rock exactly level, then hired a ‘whaka packa’ to… well… whacka packa it (compact). That was my job, done in parts while Bernt levelled the next bit. Next we had to roll out 250 square metres of a geotextile fabric, slowly, adding sand on top as we went otherwise it blew away. These jobs were often made more difficult by a playful puppy who decided that a huge roll of fabric was heaps of fun to chase and bite at. It felt a lot like we were making some kind of huge quilt.

 

The neighbour helping us level the fine crushed rock. 

Boxing came next. Our slab is a floating one, with no footings so we had to build an edge all of the way around into which the concrete would be poured. We had ordered some timber straight from the mill a couple of months earlier for the purpose. The slab was to be 325mm high (allowing a 100mm cover over the waffle pods). So we spent a few days tripping over stringlines, making triangular bracings and fighting off a biting dog. But it was a spectacular thing to see at the end, the exact footprint of the shed for the first time, we could walk around in it, and of course the boxing was beautifully straight and level (except for some bits at the end when my laser level started going wonky and begged to be recalibrated.)

At about this point Bernt decided to go home to Holland to help his dad move house (and pack up all of his stuff that was still there) so we had a bit of a mad rush to get everything organised in order to pour the slab before he left. We had been convinced that we shouldn’t do the concreting ourselves so I got a few quotes with very varying results. We ended up going with a guy suggested to us by the guy who was removing the timber from the cleared block next door to us. I was really happy with the guy we chose, he sounded very professional and his price was really really good! I ordered 40 cubic metres of concrete and organised a concrete boom pump (a truck with a huge crane-like arm which pipes the concrete out of the concrete truck and moves around the slab to pour it where it is needed). It was all a bit short notice, I gave them just less than two weeks notice, but I managed to organise everything we needed.

Then I had to organise a council inspection. We poured on the Tuesday but the latest the inspector could come out was the Friday before so we had a mad rush to get as much of the infrastructure in as possible for him to inspect. Levelling the sand took some work (more digging) then we had to roll out a layer of plastic (to stop water getting in the slab). The plastic had to be taped together at every join (and every hole). This was tricky around the plumbing pipes, especially as it was a warm day so the duct tape would stretch out then contract later, buckling all of the plastic. Fiddly! Then polystyrene pods, trench mesh (the steel around the edges), then reinforcing bars running between every single polystyrene pod (they have a 100mm gap between them), then spacers on top of each pod on which sits the 6m x 2.4m steel mesh. The mesh was hard, it of course was really heavy and we had to carry it over the pods to put it in place and THEN we had to break down the cage we had earlier built to house the pods. SO that was a big job, 21 sheets of it but we managed to do it just the two of us (bit more swearing involved). Yay for us! All of the steel had to be tied together and we still had a few gaps to fill with mesh.

Around this time Bernt’s mum Froukje arrived for a short, we were still in a panic to finish all of the last minute fiddly bits before the council inspector came. She gave us a hand in those last few days which was a huge help. Froukje and I tied in all of the starter bars (the bars which stick out of the slab to tie in the block walls to be built) as well as finishing off placing the ‘bar chairs’ (spacers to lift the mesh up off the pods). We also tied in the perimeter bar which was an extra thick reinforcing rod for the edge of the slab. There were so many things to ‘tie’ together, I thank god for this special tool we bought which you just hook into the looped end of the wire ties and pull on, it then twists the wire tie without you having to do any wrist movement at all. One company who quoted on our slab materials had just quoted us a spool of wire to do all the tying, we would have had to twist hundreds and hundreds of the damn things by hand…. Crazy!

While Froukje and I did the fiddly bits, Bernt dug two holes for two posts which will sit outside the slab. Poor Bernt, I hope there’s no digging for him to do in Holland, he needs a break from the shovel and wheelbarrow. He also bent all of the starter bars for us. I needn’t have stressed about not being finished before the council inspection, he was very relaxed; just really measured to make sure we were using the right thickness steel. Very easy!

So the last few days comprised of late nights working till the sun went down (9pmish), scrounging around to feed ourselves without the time for a properly prepared meal and an increasing excitement for the pour day. And then it was the night before the big day…. Felt like Christmas Eve for me. I was so excited and nervous that we had done everything properly.

And then the BIG DAY arrived!!!! We got up early early, made our way to the block with cameras charged and at the ready! The concreters arrived at 6:30, relaxed and confident (thank god someone was J). Then the boom pump arrived at 6:45, then… the first load of concrete at 7! Literally, THE MOST EXCITING DAY OF MY LIFE! I think the blokes all thought I was a bit odd; I may have done a few little dances, and yes… perhaps there were a few muted squeals of excitement… so sue meJ.

And then they poured and poured and they smoothed and smoothed and concrete truck after concrete truck arrived and left until the last of the 8 concrete trucks emptied his last drop of concrete. And the concreters were so so good, they just knew what they were doing, one even sung a little bit ‘lovin you is easy coz you’re beautiful’  (He never did try that high bit..). I felt exactly the same about the concrete (perhaps HE wasn’t singing about the concrete though). And the best bit was that after 2 weeks of working our pants off, we could sit, relax and watch someone complete the job to perfection! And it was perfection! They went over the floor in the workshop (because it will remain concrete without any covering) again and again with the helicopter trowel (a machine that has blades that spin around and around to finish off the surface.. much like an upside-down helicopter… perhaps that’s why they call it… nah never mind…J). They went over it so many times that it shone like a mirror by the end of the day. It is a beautiful finish; we had no idea how good it would turn out! They finished by about 3 in the afternoon and Bernt and I had our first walk on it. Barefoot. Just beautiful! And so exciting! I wish you all could come and have a walk on it!

So now we have something solid that we can call our own! It’s all up from here, literally. Next the timber frame and the walls and roof, but I’m getting ahead of myself… Now there will probably be another huge gap until my next update because Bernt is in Holland for 3 weeks then we have to go to the bank for some more money. Until next time…

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