Week 9 (8-12 Dec 2014) Concrete Slab Pour

The weather has not been helpful over the weekend and meant that the we were unable to get the slab ready for pouring on Tuesday. However, we were good to pour on Wednesday.

The floor box for a power point in the lounge was mounted so it was flush with the surface of the slab.  A hole was dug under the location and the XPS foam formed a continuous layer of insulation around the box. 

Spare FRP dowels were hammered through the XPS insulation into firm ground.  The dowels provide a solid base with little thermal bridging.

Additional temperature sensors were added directly above the previous sensors mounted at the base of the piers.  This will allow a measurement the difference between both sides (above and below) of the XPS

Wet area earth bond and Kordon termite barrier

The first slab ready to pour

A small rain shower arrives after the slab screeded.  Fortunately, it was only a small shower and did not cause any damage.

The next day the slab had cured enough to setup the other pours.  The formwork was removed from the construction joints and Intello membrane taped to the previously poured slab. This is to provide an airtight barrier when the join expands and contracts.

A pocket of intello is left to allow movement after the second slab is cured.

In the areas where the garage slab sits on the main slab, there is 20mm polypropylene packers to provide a thermal break as the garage slab is outside the thermal envelope and not insulated.  Also, more of the FRP dowels are used to reduce bridges.  The packers have an approximate R value of 0.7.

Pouring garage slab.

Week 4 - Piers

Finally got the contracts signed for the ICF walls and concrete slab on Saturday.  The concretor was on site Monday, measuring up for the pier boring that was scheduled to start on Wednesday - Tuesday being a public holiday in Melbourne for the Melbourne Cup.

The first hole, of the 150 in total, was started on Wednesday morning (just.. after a few dramas with flat tyres on the excavator transport work commenced about 11:30).  By the end of play on wednesday evening, about 30 holes were complete but it was about this time that we discovered that the 600mm auger had been used instead of the 450mm.  This slowed things down a bit and meant that there was a lot more dirt coming out of the holes than expected.  The good(?) news is there will be a lot more concrete in the ground...

Yet another machine on site, digger count now 5.

The drilling uncovered some of the old foundations of the original house that was on the site.  The block on the left was the sum total of the concrete footings under each stump - a little bit different to the footings of the new house.  For scale, that is a standard house brick on the right of the photo.

Got to give it to the concreters, each day starts with an espresso, brewed on site..

All holes were done by Friday afternoon ready for the building inspector - all passed with flying colours.

 On Saturday morning, 8am the concrete pump was setup and ready to go for the first of the 45m3 of concrete to be pumped into the holes.  Don't think we made any friends with the neighbours with the air horn of the pump truck blowing at the end of every hole to alert the concrete truck drivers to stop filling the hopper.

I took the opportunity to place a temperature sensor at the bottom of the 3 of the piers.  The idea being to check the ground temperature at 2m below the surface and see how the data from PHPP compares.  The data will be logged and plotted over the year.  Additional, sensors will also be embedded into the concrete slab above and below the insulation and in the ICF wall to profile the performance of the insulation.  Of course, this info. will be too late for our build but may be useful to others in the future.

The sensors are a DS1820 digital thermometer with a 0.5 degree C resolution purchased on Ebay.  To make readings I will need a small computer, probably a Raspberry Pi, or Arduino to decode the signals from the sensor.

 After concrete was in the pier.