Week 18 ( Feb 9 - Feb13) ICF Walls, Structural Steel, Roof Frame

660 lineal meters of LVL rafters are delivered on Monday morning

Meanwhile the setup for the final pour of the ICF walls is completed.  Only 3m3 of concrete to complete the job.

This time only a small concrete pump is required.

The final pour!

Tuesday saw some the the braces for the ICF walls being removed.  More braces were removed on Wednesday, the Carpenters arrived and we get our first LVL beams into position.  Issues with the ICF pour on Friday meant that all of the top plates were in place or at the right levels.  This meant more work for the carpenters.

Thursday and the cranes (http://www.buchanancranes.com.au/) arrive to lift the structural steel into position.  There are only six lengths of steel, two penetrating the thermal envelope (more on this later)

The Franner crane moved the steeel from where they were stored on site and lifted them onto the slab as close as possble to the final location.

A crawler crane then was able to get to the back of the house and lift the steel from the slab to their final positions.

We had previously set the mounting bolts into the ICF concrete in the correct.  The steel all fitted without a hitch except for one tab that had to have the corner cut off to miss a block on the fireplace.

While the crane was on site we took the opportunity to move the tank into its final position.  Woops, forgot to mention that we had built a garden shed in the way - no probs though..  Now all we need is a roof and rain!

Week 15, 16 & 17 ( Jan 19 - Feb 6) ICF Walls

Work continued with the ICF walls.  The formwork for the window and door openings was put in position and secured with the plastic webbing imbedded the foam.

 The braces were also fixed the inside of the walls and screwed to the floor.  As the floor was being polished the number of screws in the floor was minimised as much as possible or located under stud walls.  In some circumstances, timber was screwed down to areas under stud walls and the braces fixed to the timber.  The wall braces also provide plank supports to allow work to be carried out on the upper parts of the walls.

 In a previous post the air tightness and thermal bridging of the fireplace was raised as a concern.  To minimise the thermal bridging the internal and external fireplaces were constructed as two separate structures with an 80mm gap between the two.  Into the gap an Intello membrane was added to ensure the air tightness layer continues past the fireplace.  This was embedded into the ICF walls at each end of the fireplace so that a tight join was achieved between the concrete in the ICF and the Intello fabric.  On the outside of the Intello 75mm of XPS foam is installed to provide continuous insulation from the ICF --> Fireplace --> ICF.

Below show the Intello in place with the first piece of XPS installed.

 The plumbers returned to site to install the sewerage pump tank, grey water system and fix the retaining wall that was undermined by the sewerage tank hole.

They also dug the trench down the slope to the water tank.  The power and data cables for the pump and shed were also laid in the trench.  The roots from the surrounding trees formed a damaging obstacle course will laying the pipe and conduits.  Note the flexible pipe used for the stormwater to be tolerant of any land slip issues over time.

The trench continued past the tank and connect to the legal point of discharge half way along the back fence.  The total length of the trench was approximately 70m.

Back on the ICF walls, Intello membrane was sandwiched between the top blocks of the ICF walls.  This was done to ensure an airtight connection between the concrete in the walls and the membrane that will be installed under the roof rafters.    When the ICF walls are core filled the membrane will be encased in concrete.

On the inside (of the thermal envelope) of the wall the membrane will be folded up and taped to the membrane under the roof.

Some of the wall are ready to be filled.

The short block wall near the Alfresco was completed - also ready to be core filled.

Conduits that are to be imbedded in the wall are sealed to the Intello membrane. In this case the conduit start and finish was within the thermal envelope but due to the way the blocks fell, the membrane was below the top penetration of the conduit and needed to be sealed to the membrane.

Other conduits were embedded into the walls to save chasing the foam later.  But as these conduits were in the garage (outside the thermal envelope) they did not need to be sealed.

Finally, after a number of delays the day (Friday 6th Feb) came to core fill the walls.  But as the first concrete truck did not arrive until 10.30 and the day was 35 degrees. There were a lot of stress and issues on the day, hence not many photos.

The fireplace was also filled.

After 12 hours on site (6pm), and 8 hours of core filling we had a block blowout, which dumped a cubic meter of concrete on the floor.  It would be another three hours before we finished for the day, unfortunately without the job complete and more core filling would be needed on Monday.

Week 14 (9-12 Jan 15) ICF Walls, Fireplace

 Work continued (slowly) with the ICF blocks.  It was surprising how much additional equipment was required with the ICF system.  Mainly wall braces which keep the walls square during the concrete pour and also provide platforms to make the process of filling the walls straight forward.

Work continued with the fireplace

 The alfresco - fireplace is nearly complete, of course it rains before the grout is dry so it had to be covered.

The internal fireplace started with the heater in position.  The fire insert was sourced from Euro Fireplace based in Mansifield (http://www.eurofireplaces.com.au/)  They source the units from Europe and we have been very impressed with the quality of the build.  The inside fire is in the lounge room and while will be used for heating, it is mainly aesthetic.  From a Passive House perspective it was important that the fire was extremely well sealed to meet the airtightness requirements.  to achieve this, the fire gets all of its combustion air from the outside of the building envelope.

 Both fireplaces complete!

One of the water tanks arrived today.  A single 45,000 litre fiberglass tank.  The only problem was that the trailer was so low it was impossible to get the trailer down the driveway.  Luckily the bricklayers were willing to help with rolling the 800kg tank down the 40m long, 11m drop driveway.   We had 7 tyres which had to be moved from back to front all the way down the driveway so the edge flange was not damaged.  After, a certain amount of scepticism from me and a great deal of experience from the delivery driver the tank was safely down the hill ready to be craned into its final position in the coming weeks.    

Week 13 (5-9 Jan 15) ICF Walls, Fireplace Block work

A little more activity now the "Silly Season" is over, though the construction industry in Australia winds up slowly!

The starter "C" channels were nailed in position after again checking wall positions and putting down chalk marks - the slab edges were mostly correct but there were a few places, e.g. the edge near the garage door where form work moved during pouring. 

Holes for starter bars were drilled in the slab and the bars were "chemset" into position.

Once the "C" channels were in place the first blocks could be laid in position.

The corners are preformed and have additional insulation on the outside corner.  The helps with geometric thermal bridges - a nice little feature of ICF.  Also, an engineering requirement was to have reinforcing steel horizontally at 400mm centres.   The ICF blocks used in the project have a vertical height of 400 so steel is laid on the clips which hold both pieces of the ICF together.  

One issues was what to do with the ICF wall over the construction joints in the slab.  While engineering called for and expansion joint it did not detail how to achieve it.  The ICF company had not come across expansion joints before as the ICF walls are usually poured in one section.

The solution was to put a concrete cement sheet with lagging attached to one side directly over the construction joint.  As this would create a wall without continuous steel reinforcement, dowels were placed in the wall horizontally with one side taped up to allow for a sleeve to be produced when the ICF concrete had cured.  Since there is a possibility of exposure to air the dowels were galvanised.  

Of course, this produces a potential air leak and the Intello membrane should have been applied to the joint - unfortunately, this was missed at the time of the pour and will need to be retrofitted later in the build. - don't forget!

Untaped end of dowel

Taped end of dowel

 Work commenced on the Block fireplace - see later posts for how insulation and air tightness was achieved.