Monday, 28 April, sees us welcome a new team member to Ian’s band of creative producers. Jib (his real name) joins Damien and Nathan, the site foreman, for at least the next month. All three are carpenters-plus, as the photos in this post will show, prepared to do what is needed and having the varied skills to do it really well. In separate, brief conversations all three say the same thing to your blogger: working on a bog-standard building is something they refuse to do. So they were attracted to our Hobart hill house project because they think it’s interesting, different and exciting. Combining their individual skills and abilities with working together means great outcomes are possible; we are in no doubt that we will get a real-world result that matches the intention of our architects.
Today is concrete pour day no. 2. The plan: core-filling the block work and pouring the upper path’s structural component, the 30-mm (1 ft) thick slab into the formwork and steel so painstakingly prepared over the last week and a half. The scaffolders are back today too and are just starting to risk slowing the job down if they don’t finish erecting soon.
Nathan carries the last of the bits and pieces down the path to get ready for core-filling the block foundation and retaining walls below. The special cast-in plates will be inserted into the top of a block according to where the small number of steel universal beams will need to be. The beams will then be welded to the plates. Without realising your photographer is shooting, Nathan uses best practice: walk between the steel mesh not on top of it whenever possible.
The concrete pump truck – this one the next size down from the behemoth that came to do the first pour – is on site. The boom operator and his offsider get set up so when the concrete trucks arrive not a minute is wasted.
Booming up and out
Booming down … down … down
Ian says concrete trucks are always either early or late. Today is no exception – they’re late but they are on their way!
The merry band of carpenters-plus – today concreters and finishers – Nathan (left), Jib and Damien (right) waits. The small-diameter boom hose, looking like an elephant’s trunk, sits inside a block next to Damien.
The long steel reo bars in the corner will be used one by one to manually agitate the concrete a bit before being left in situ.
The core-filling begins while Ian (bottom) reseats a plastic ‘chair’ that supports the mesh in the path, to be poured next. Damien is agitating with a long bar while Jib briefly looks on. The boom operator’s offsider will keep moving to the right until all the holes are filled.
Damien remains agitated! Jib trowels like mad! The operator’s offsider just keeps filling the cores.
The safety of the team of workers and protecting the gum trees from damage are two sides of the same coin. All crane operators – no matter what type – learn that trees, if present, are a significant site hazard to be taken constantly into account.
The operator slowly and carefully moves the boom to the right as far as he can to allow his offsider to reach the lower block walls with the hose. Knocking any branches down on top of the workers below could cause serious injury or death. No incidents occur and the tree is fine too.
As the team finishes off the first stage of today’s pour, the boom operator booms up to prepare for stage 2: the bulk pour of the upper path.
Jib (left) cleans spilled concrete off the honed blocks, which will be visible after the house is built. Nathan looks at the long reo sticking out of the tops of the blocks and the cast-in plate which the steel beam will be welded to.
Jib places threaded rod that will tie the foundation wall in with the timber beams that will be installed to form the under-floor structure, in this case, of the upper level of the house. Once the threaded rod is set in the concrete, the timber cleats will come off.
Stage 1 of today’s pour is finished. From the arrival of the first batch of concrete to this point has taken 60 minutes. This hour marks a major turning point and allows for a timely reminder: despite appearances until now, with the foundations needing only a few more steel poles welded on to support the art studio later this week, this is a timber house not a brick house. On to stage 2 of the pour!
The small diameter hose comes off (left), with a big diameter hose waiting in the foreground.
The diameters have more to do with the character of the concrete mix than with the need to have a small diameter hose to fit above the block cores.
The core-filling mix is runny so it would completely fill the blocks after just a bit of hard agitation from Damien. But the stiffer mix for the upper path would simply not pass through such small diameter pipes.
After the hose, the pipe comes off, to be replaced by the big ones.
The team of three carpenter-concreters heads up the hill for the final preparations for stage 2. After a hard hour’s work, and anticipating more, only the shirts (below) look different from today’s earliest photos.
Jib does some final steel-fixing where pour 2 will begin, adding one more layer of mesh to the landing.
One more twist of the fixing wire and it’s Battle Stations!
Stage 2 of today’s pour is on!
Up to their shins, Nathan (bottom left) trowels the footing for the low block retaining wall that forms the ‘L’, Jib (right) screeds (levels) the concrete on the path, Damien shovels in the background while the pump keeps on placing.
The pump is idle briefly and the men get caught up.
Perhaps it’s time for a final photo of the pour from a different angle.
Zooming in from Proctors Saddle, about 300 metres (325 yards) to the east.
The next day, stripping the formwork reveals … a materials storage area!
Hobart hill house 
What you don’t want to hear: “Oops, sorry mate, we poured your concrete okay but it slid down the hill to next door’s block.”
That’s why everyone is thrilled we are past the foundation stage!
I was thinking along similar lines, how do you get wet concrete to stay put on a slope?
I’m out of my depth here but I do know that concrete is a wonderful, plastic material. Humans have been creatively using it for more than 2000 years (more on that in a future post). I reckon it’s all about the degree of steepness. Depending on that, either vary the mix proportions or support the concrete with a mould or formwork. Our paths have been designed to have a slope of 1 in 10, which is gentle, and that, combined with a stiffer mix (less water), means little or no risk of it slumping. Our neighbour across Woodcutters Road has a driveway that is on a very steep slope, as are many of the driveways in Tolmans Hill. He’s also a retired concreter from Bankstown, NSW, so maybe I’ll ask him! In the meantime, I’m sure we’d all appreciate someone with some real knowledge stepping in!…
Do these guys have any idea that they’re internet stars?
A very fair question, Michele. Yes, they have given their permission to be photographed and the blog address is on the whiteboard in the site office.