Electricity Connected, Frame Ordered and Mixer Purchased

Last Friday my excavator dug the trench down the battleaxe driveway to run the electricity and water connections. Unfortunately I could not be on site on that day, but having waited a little while for the excavator and there being a run of good weather I was not going to give up the opportunity to get the job done. Len my plumber had left the water pipe on site ready to be laid and I lined up FAW Electrical to arrive on site to put the electrical cabling in when it was anticipated that the excavator would have the trench ready. Brummy, my excavator reported that digging was tougher than expected due to more tree roots, but the trench was dug and the electricity and telstra cables and water pipe were laid.

FAW were back on Monday to hook up the pole and the flying fox to the wires in the street. The electricians set up the meter box on a temporary post right were it will be placed on the house, so it can be easily placed on the house. The pole from the street is much taller than I expected, but it looks like it was necessary so as not to interfere with the neighbours connection. Finally we have power on site.

 

Last week I ordered the frame from Truss-T-Frames and spent a couple of days this week ironing out a few problems. I drew the plans but they needed a few adjustments and Colin from Truss-T-Frames was very patient with me as we spent several phone calls discussing wall heights and roof pitches. I redrew the plans to match the adjustments made and they all fitted perfectly, except the roof pitch over the front bathroom was less than the minimum 5 degrees. The interconnection of various aspects of the roof and awning made it difficult to change too much as each change had flow on effects. Finally Colin came up with a cleaver idea to raise the pitch without altering the awning height or the gutter height, by moving the ridge on that section back slightly and trimming the corner off the top rafter.

However the changes to plans that have been made will increase the wall volume, so I have had to make a small increase to hemp and binder I am ordering to ensure that I will have enough walling material.

To get ready for the hemp walling. I bought a 111L mortar mixer (which I call a pan mixer, but it is the same thing) from Aardwolf Australia. It was made in Vietnam and came all wrapped up and in its own crate. When unwrapped we tried it out, the first appliance to use our electricity connection. The mixer was beautifully quiet, a great benefit since we will probably spend many hours working with it. However we tested it out empty, I just hope it is as quiet when it is full of hemp walling mix.

Mixer all packed

Mixer unwrapped

Back on site we covered the polished slab with black builders plastic then some of the sheets of OSB we had that were not good enough to use as formwork. We moved 3/4 of the mulch pile, using it to cover up the area beside the drive that had been dug up for the electricity and water. This was to make more room for the frame that will be delivered next week. In further preparation for the hemp walls I bought two boxes of M8 100mm hex head coach screws and cut up some scraps of conduit I had in the shed and was given by my father into 55mm sections to use as spacers for the formwork for the walls. The walls will be a total of 200mm thick (plus 10mm render each side) formed up using the sheets of OSB I have attached with a 55mm spacer and a coach screw into the 90mm frame, the same will happen on the other side giving a total wall depth of 200mm.

Covered slab ready for the frame

Once was conduit now are spacers

Concrete Polishing

It was a glorious site to see the finished slab stripped of all its formwork. It looks quite thick but the depth is due to the Styrofoam waffle pods in the slab. For the first time we really got a chance to walk around the house and feel how the layout would work and watch as the sun shone through our, for now imaginary, windows. The room sizes felt fine and I was pleased with how well Ken's earlier suggestion to tilt the front pavilion worked.

The finished concrete slab

The concrete polishers, Henry and Adrian from the Dayman Group, arrived with their grinding machine to take off the top layer of the concrete to expose a little of the aggregate. The machine was not as loud or aggressive as I had thought and it operated wet so there was no dust. Instead there was a sloppy muddy slurry that was squeegeed off the edge, so that the machine operator could see how much they were grinding. It was slow methodical work.

Adrian and Henry grinding the slab

When Adrian and Henry first started they did under the kitchen cupboards and we had to look to confirm the level of grind we wanted. The look we chose was a little more than just the fines showing with only a little of the aggregate showing. After the front pavilion was done we did another check just to confirm the look we wanted.

In Nowra we only has the choice of river stone or blue metal aggregate. We definitely did not want the blue metal look, so the river stone was our only choice. We are happy with the river stone's random colours from whites, to tan, to olive, and this looks great with the darker grey oxide we put in the concrete.

Concrete is tricky to photograph

This afternoon after confirming some drainage locations with our plumber, we left Henry and Adrian to finish the grinding. Once finished the concrete polishers will put a temporary coating on the slab, before returning after the walls are done for the final grind and seal. We headed up to Truss-T-Frame Timbers to finalise the frame order and discuss a few of the unusual details of the design. We got there 5 minutes before they closed (oops) and David kindly stayed back to discuss the frame with me.

Ideally we would have ordered the frame two or three weeks ago, so it was ready to go up once the concrete polishers were finished, but time has been taken trying to finalise the awning detail, and it is time well taken as changes to the awning affected the stud spacing. Thankfully the frame will only take a couple of weeks, and this will give me time to organise someone to put it up.

Concrete Poured

Tuesday the concreters were back on site laying the plastic under the slab, followed by the Styrofoam Waffle Pods and the steel reinforcement. I was not familiar with the Waffle Pod system, but it appears to be quite popular of the South Coast. I was initially concerned about the environmental impact of using all that Styrofoam, however the Styrofoam will provide some insulation to my concrete slab, which I intend to use as thermal storage. In addition the Waffle Pods create a series of integral beams across the slab, stiffening it and theoretically these beams mean that the slab can use less concrete in other areas. To me it still seemed like a lot of concrete. The Pods did raise the slab up a bit, which was particularly useful on the side that had been cut in to level the block, since no additional fill had been used to level the block. This means that the whole of the slab will be above natural ground level, useful to prevent flooding.

Waffle Pod installation - photo sent to me by me concreters

Steel reinforcing installed - photo sent to my by my concreters

 The Termimesh installer put the stainless steel mesh around the pipe penetrations and across the control joints. This is to provide a physical barrier against termites entering the house unseen through these areas. I preferred to use Termimesh over a chemical barrier. 

Because we are having a polished concrete slab the Engineers specified additional steel mesh reinforcement and stiffer concrete (32MPa). Where the hall joins the middle and back pavilions together there was a weak point and so control joints were put in. The hall will be poured tomorrow. The other possible weak section is where the front and middle pavilions join, so extra steel was specified here.

Early in the morning- Formed up ready for the pour

Lots of steel in that tricky join

The formwork was all in and ready to go. the concreters had put additional timber on the formwork to create the step down at the edge of the slab, as well as additional set ins for each of the sliding glass doors and the lowered sections in the bathrooms and laundry, so that when they are tiled they will be flush with the polished concrete slab.

Early this morning I heard the rumble of the concrete pump arriving. It was like something out a Bob the Builder episode, and the concrete pump was enormous - and bright yellow.

My car and the garage look tiny next to the huge concrete pump

The concrete pump had a long reach - right across the block

The concrete was pumped into place, shovelled a bit and vibrated, before being levelled, screed and floated. Today's pour used about 30m3 of concrete - that is five concrete trucks. No very good for my carbon footprint, but I hope that the thermal mass provided by the concrete combined with the solar passive design of the house will mean that we do not need any heating or cooling, reducing our carbon footprint in the use of the house.

Starting with the front pavilion

Moving on to the middle pavilion - excavator in the background is
providing bracing for the formwork where the soil was soft from
the removal of the tree roots

Levelling and screeding

Finishing up at the back pavilion

The concrete had a little bit of colour added, so that when it is polished it does not have that typical light grey concrete colour. But we did not go too far from the natural colour of concrete, choosing Onyx 3% from the Concrete Colour Systems colour chart, which is a dark grey. We will not be able to see how it will look until the concrete is polished and sealed.

All finished - except the hall - A job well done

House not in the right spot

I was thrilled to receive a phone call from my concreters on Tuesday advising me that they had drilled and poured the piers that day. The concrete piers had to go down to the reddish coloured subsoil. The concreters had encountered some unusual metal and other rubbish in the location of the old swimming pool, but the piers have gone down to the subsoil beneath. They then started on the set out and formwork. My concreteres called me about an issue with the house set out not matching the plan and I gave then the surveyors details so they could contact the surveyors directly. Wednesday and Thursday my plumber came in and put in all the waste pipes that will go under the slab.

Plumbing in

I was on site late Thursday and was woken Friday morning around 7.30am by the concreters arriving. Before I had a chance to have breakfast I was struggling with issues of part of the set out of the house being incorrect and the front section of the house having to be moved 20cm away from the boundary and 20cm towards the front of the block. The problem with the peg having to be being moved to match up with the rest of the house, was that it was the one spot from which I had located the whole house on the block. This was very annoying as I had spent many hours working on the plans and carefully locating the house on the block and designing it within the set back requirements.

On site first thing Friday morning

 After the surveyors pegged out the house I was sent an original drawing showing the locations of the pegs and the set offs for the house. But I was contacted by the surveyors before I even received that drawing to be advised to ignore it as it was incorrect. I was then e-mailed and posted what the surveyors told me was the correct drawing. A day later while the excavator was on site the surveyors came out to check the survey again. In retrospect I wonder if they thought something was wrong, because even after all this the surveyors still got it wrong. At least my concreters could do their maths and got it right.   

The problem was that the piers had been done for the whole house based on the peg out done by the surveyors which was incorrect. The front section was pegged out in the right spot but the middle and back sections were incorrect. However, after all the piers were done it was less difficulty and expense to move the smaller front section rather than the larger middle and back sections of the house.

I designed the house to go the whole way across the block to make best use of solar access, so I was worried that by moving the house in one direction, the setbacks would be too close in another direction. Some further measuring and checking on the computer CAD drawings showed that this was, thankfully, not the case and I could calm down and have some breakfast.

The change to the location of the front section of the house meant that more piers had to be bored and concreted, meaning further cost to me after paying for surveyors to peg out the house, which they did incorrectly.

Filling with concrete

Pier holes bored

The concreters then continued putting up the formwork, which was now checked and double checked and as I had the CAD drawings of the house on my on computer I was able to give them accurate dimensions to check diagonals across the different sections of the house.

Even in May I still had an afternoon swim at the beach. Refreshing after a day of moving more timber.

Culburra Beach late afternoon in May

Saturday morning I carefully checked the house formwork dimensions. The concreters were very accurate, mostly to the millimetre. Impressive given that it was all done with stakes and timber, and a relief given the earlier set out issues. At least the house will be correctly set out within itself, even if it in a slightly different spot on the block to where it was intended. Next week the concrete pour.

Formwork from the front of the block

And formwork from the back of the block