8 Mar 2014

Finishing the slab

What a week!
  
(Settle down and get comfortable, this is a long one)

In order to minimise costs the design is that the foundation slab is going to be our finished floor - polished concrete.  How marvellous and clever we all thought we were...

The underfloor heating went in.  Charlie (so now we have Charlie, Charles & Charlie on the team) and the guys from Cotswold Green Energy took a day to get all the piping laid. The underfloor heating pipes were tied to the mesh.  Each room has a separate loop so if we were so inclined we can control each room individually.






They had to know where all the walls were going to be so the layout was marked.  This was really cool for me as it was the first time I could really get a sense of the dimensions of the rooms -I'm very happy with it all!







Mesh, mesh and more mesh was laid.







And then - the concrete was poured!






We were under a huge time pressure.  In order to get a polished floor we needed to powerfloat the concrete as it cures.  And we've discovered that this is not as straightforward as it sounds...!

To give us the best chance of getting the job done properly we decided to pour on the day where the best weather for weeks had been predicted.  Of course, everyone else had been waiting for a break in the weather too so our preferred suppliers were fully booked. However, Andrew (what a hero!) doggedly persevered and succeeded with finding an alternative supplier and concrete pump.







We ordered the concrete for 8am sharp, of course the first concrete lorry arrived 1.5hrs late! They poured about a 1/3 of the slab. Then there was a 40min wait before the second lorry appeared.






The pouring was really efficient.  We had two experienced concrete layers and finishers from GAR Contractors present to help Andrew and Paul, and they all made it look easy.  






Andrew was busy checking levels as the concrete was laid.






Bit of vibration to smooth and settle. And some hand-finishing to smooth the edges.






Then it was a waiting game...

Apparently concrete curing is a "black art".  No one can predict when it will set, even the most experienced professionals.  I was told again and again that no one knew when it would begin to cure - it could be 3hrs or 12hrs.  There are apparently far too many variables.  My scientific mind found this very hard to deal with - 'What do you mean you don't know!!!'.

The concern was that I really didn't want to disturb and upset our neighbours.  Powerfloating has to be done as it cures, you can't wait until the next day, it's too late.  The powerfloating machines, I was assured, were the quietest machines in the process, just a low hum. In addition the powerfloating is not continuous.  The machines pass over the surface which can take 20-60mins, only every couple of hours.

We kept our fingers crossed that it would cure during acceptable site working hours (8am-6pm).  We had done everything within our power to maximise the chances that there would be the minimum of disturbance.

I went home and waited for updates.  At 6pm I was called to say that the concrete had only just started to set at 3pm, so as they had only managed one pass they were going to stay on site as late as they could.

We dispatched emails to neighbours explaining and apologising for the situation.  We had one friendly response from the nearest neighbour who told us it was barely noticeable.  In the end the guys left the site around midnight.  They did the final pass using the machines about 10:30pm when another neighbour came to complain and asked them to stop.  After this they did any further finishing by hand.






They weren't able to get to achieve the finish we had asked for, this would have required another couple of passes.  However there is no way that I would have felt comfortable with them working any later.  So it is what it is...



It is shiny due to the rain!


Dimitri was on site a couple of days later, to meet the surveyor acting for the mortgage company (yes we are STILL waiting for a stage payment release) so managed to drop off a bottle of wine to all of those disturbed and also had a friendly chat with the neighbour who had come on site to complain.  All neighbourly relations are thankfully still intact.  








The slab is smooth and flat in general.  Where the concrete was poured first, you can see the markings of the powerfloater but you can't feel anything.  Where the pour was later, you can see and feel the ridges, not hugely by any means, but enough to wonder whether we have a finished floor finish yet.

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