The Slab

Once the sand was compacted and level I called the Building Inspectors to come and check it.  The inspector who came was very happy with it and was generally complimentary about the quality of the work so far.


I had bought 6 one metre lengths of 12mm rebar to join the new slab to the existing one.  These needed drilling into the side of the existing concrete - about 50cm - then locking in with injected resin.  This took a while but made a good join.  The difficulty then was setting the damp proof membrane on the sand and the perimeter insulation around the edge with the rebars coming through the membrane.  This has meant that the dpm is not watertight and I will need to paint a damp proof course on top of the slab before putting the insulation down.

I ordered 2.1 cubic metres of concrete - which I discovered was about 5.2 tons!  With enthusiastic help from Emily who waded in concrete and Zulum who chose the big barrow, we had the slab laid in good time in steady rain.  

The rain will not hinder the setting of the concrete, in fact slowing the drying process makes the curing better and results in stronger concrete; but it might spoil the finish. As it is not the top screed I'm not unduly worried about the finish - at least it's level.

By the evening it had pretty much set though it was difficult to see the finish.

Now that the floor slab is down I can start to build the walls, there i no need to lay the insulation and screed until I'm good and ready.  So the next phase is to attach the wall starter plates, lay a mortar bed all round on both sets of blocks and set the damp course on top.

Once that is on a second layer of mortar takes the next row of blocks all round, though the 3 metre gap for the bifold doors will leave a significant part of the wall looking rather bereft.  I will make a wooden frame, 3 metres wide and 2.1 metres tall, ensuring the corners are square, to use as a former for the opening.  A second one will be useful for the window over the sink.