Week 11&12 Xmas / New Year

Works slowed on site over Xmas and new Year.  The ICF team spend a couple of days on site preparing the job but not much was going to happen until the first week of Jan.

Waterproofing painted on slab edge, where ICF walls will be located.

On top of the waterproofing the Termite protection (Kordon) was was glued and nailed into position.

Ready for the "c" channels of the ICF walls

Week 10 (15-19 Dec 14) Slab Cure, First Cut polish

After the slab was poured, it needed to cure for one week before the concrete polishers could do the first cut.  The process took three days and produced approximately 2 tons of concrete dust, of a similar consistency to flour.

We are using Revolution Concrete Polishing (http://www.revolutioncgp.com.au/)

The construction joint between the two slabs is designed to allow movement between the two slabs.  It is working as designed with a difference of approximately 3mm between morning and afternoon. The gap is visible as a dark line directly below the coin.

With the run up to Christmas the country is slowing down for a two week break.  As such work is grinding to a halt on site.  We were able to get the slab down for the garden shed and 45,000 litre water tank at the back of the block.

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 8 (1-5 Dec 14) - Underslab Insulation, formwork

Installation of the XPS foam began on the weekend in very hot (for Melbourne) conditions.  The detailing of how the XPS foam was to be installed was not well defined and practically became extremely difficult to come up with a workable solution.

What should have been installed

The initial concept for the build was to put the foam on top of a structural slab with a further screed slab on top.  This would have allowed for a very simple installation of the insulation with minimal thermal bridges.  Unfortunately, the structural engineer persuaded us to use a single slab on a cost basis.  In reality, the original concept would have been less expensive and much simpler to implement.  Lesson learnt!

What was installed

The issues were as follows ;
The foam was not self supporting and needed to be pegged in position.  As the raised elements of the  slab i.e. the bits between the beams was not precisely cut, because in a normal slab the concrete fills the voids the foam had to be backfilled to prevent the foam being pushed in when the concrete was being poured.  This caused another problem as before the concrete is poured there is nothing to support the backfill.  Various attempts at finding a solution were tried and failed. Finally, it was decided to leave pegs in place under the waterproof membrane that keep the foam in place.   unfortunately this adds a thermal bridge through the foam in the bottom of the trench and creates a void between the concrete and the XPS.

And yes, the XPS was suitable to be placed below the damp course layer.  According to the manufacturer's specification a typical reduction in insulation of performance of 0.6%(by volume) can be expected due to water  ingress.  (see - http://www.knaufinsulation.com.au/media/1000777/climafoam_xps_board_datasheet_web.pdf)

The sequence of events for the foam installation are as follows;

1/ Foam is cut and placed around the sides of the beams - in this case either side of a construction joint.  The tops of the piers are exposed.

2/ XPS is added to the area between the piers and sand is backfilled behind the foam to stop the concrete from collapsing the foam inwards.

 3/ Top sheets are laid out and pier locations are marked so they can be cut to expose the piers

 4/ We started cutting the piers holes in the XPS with a hot knife but found a simple jig saw with a long blade was faster and provided a better finish.

5/ The damp proof plastic is then laid over the XPS and cut to expose the piers

 6/ The piers holes are then sealed to provide a continuous damp proof layer

7/ Around the outside edge of the slab the first layer of ICF foam is nailed to the inside of the form work.  This becomes the start of the ICF walling system and provides the insulation for the slab edge.

The ICF supplier is Ecoblock (http://www.eco-blockaustralia.com.au/) - sold via Polycon (http://www.polycon.com.au/) in Victoria. 

8/ Where dowels are required in the edge beam piers a pultruded fibreglass dowel is used to reduce thermal bridges between the ground and edge beams. These dowels are 20mm and manufactured by V-Rod and supplied by Inconmat (http://www.inconmat.com.au/) in SA.

9/ The ICF corner profile is thicker than side wall

Other ICF suppliers worth consideration;

• Insulbrick - (http://www.insulbrick.com.au/)
• Thermacell - (http://www.thermacell.com.au/)

Week 6/7 (17-28 Nov 14) Gabion Wall, Footings

The main services trench to front gate completed.  The electricians were on site to add the mains cables and data for intercom and other services.  In the same trench there was also gas, water, storm water for driveway drain and additional water pressure pipe to allow tank water to be pumped to front fence gardens.

On the weekend we put in another retaining wall towards the back of the block to provide stability to the path and slope.   This time we used a gabion cage wall or wire baskets filled with rocks.  The time consuming part was the construction of the cage but we were able to move 8.3tons of rock with the assistance of the Vemeer mini loader and completed the wall in one day.

The end result was in fitting with the surrounding bush area.

The concretors were back on site to complete front fence footings and get slab set up for formwork and slab pour.

Yet another digger - I have officially lost count now..

The XPS foam arrived on site, 5 piles, 150 sheets, 400m2.

Week 5 (10 Nov 14) - Site Clean Up and Plumbing Preparation

Site cleanup - moved the 50+ m3 of dirt removed from pier holes to a location easily loaded to be taken away - another machine but since I was driving it there were no photos..  Yet another machine and truck to remove the dirt..











And almost as soon as the last truck left the plumber arrived on site, measured up and began making more dirt!

Greywater
We thought it would be a good idea to add a grey water diverter system to the build so that we could reuse the water on the garden.  Perhaps its the shiny new desal plant that Victoria installed a couple of years ago, or the lack of clarity from local councils about regulations and requirements but nobody seems to buy these systems any more.  The system we were looking for would divert water immediately to the garden and not store any water for more than 24hours (regulation!).  Also, it was important that any filters would be easy to clean, and hopefully not needing cleaning on a regular basis.  The Greyflow PS (http://www.greyflow.net.au/index.php/product-selection-guide/grey-flow-ps) was chosen.  It had the advantage of being staged installed - i.e. the basic system could be installed with the plumbing and the pump and control system could be added later, once the house is complete.  It also, has the option of adding an automatic cleaning system that means filters only need to be cleaned annually.

Piers
Of the 155 piers we got 4 wrong...
We just realised that the 4 of the piers we bored and filled with concrete were in the wrong place.  Of course these were under one of the two construction joints!! However, luckily they were some of the piers that we also bored to 600mm rather than 450mm so they are still under the joint..

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.