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PostPosted: Sat Feb 18, 2012 8:42 pm 
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Location: Melbourne, Australia
As I mentioned briefly in Bluey's Rammed Earth Journey, I (Simon) and my lovely wife Alissa (avangeet here) are owner-building a family home in the Tallarook Ranges, about an hour north of Melbourne in Victoria. About 5 years ago we bought the land, 105 acres of natural bush (medium forest), hilly and ranging from mild slope to oh-my-god-steep. It has a cleared house site (done before we bought it) which is cut-and-filled into the hill.

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Our plan is to build in two stages: A garage and attached 2-bedroom unit first, and the separate 4 bedroom house later. The idea is that if we need, we can move into the garage/unit while we build the house but in the long term, it will serve as space for family and friends to use when they visit.

We were lucky enough to find an architect / builder who lives in the ranges himself who often works with owner builders, and is well versed in passive solar thermal design. I can't stress enough how valuable it is to have an experienced hand available who can not only assist, but lend advice along the way. Whatever we pay Peter, he's saved us that much again in mistakes not made...

Anyway, the basic design of the garage & unit is slab-on-ground, timber framed and Hebel clad construction with internal rammed earth and slip formed rock walls, and detailing to meet the requirements of BAL-FZ. This means 5mm toughened glass all around, with stainless fly wire mesh and steel fire shutters, and no more than a 3mm gap anywhere to admit embers. I've been reading Bluey's thread with keen interest since his requirements are very similar to ours, so I hope he doesn't mind if I end up stealing some of his ideas ;)

Here's the site plan:

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.. and my Sketchup rendering of our working drawings:

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I've been documenting our progress to date on our blog but I hope to post updates here as well as I'm eager for feedback and advice from others who've taken similar journeys themselves.

The short story is that we broke ground around September last year, poured blinding footings in December and the garage slab itself in January. I'm currently in the process of building one of the two structural walls to support the upper suspended slab, and planning to build the other in rammed earth some time in March. (It's amazing how So. Much. Work. can be distilled into one or two sentences... makes it sound so easy... :lol: )

Anyway, enough words for now!

Cheers,

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Simon.

The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Sat Feb 18, 2012 9:24 pm 
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Location: Blue Mountains
Simon,
Great to see that your thread is up and running.

You mentioned on mine that the reo is mesh (I was assuming that it was bars). I think that mesh will be ok to work with as long as there is enough space between the mesh and the formwork. It should be easy enough to avoid hitting it too much. The problems I could see are that it is going to be a pain to work around as it will stick up out of the forms especially when you are working on the lower layers. If you are using the Bobcat to lift the mix into the forms you will not have room to tip the bucket straight into the forms as the mesh will get in the way. You might need to tip the soil onto a platform first and then push it across into the forms (or use buckets, shovels etc to manually lift it in). I'm sure that you will come up with a solution.

The other difficulty is that the mesh will form a barrier between one side of the forms and the other. When you pour the mix in you can compact on one side of the mesh and you will then need to walk/climb around to the other side to compact the rest of that layer and repeat this for every layer.

Originally I was going to use rammed earth for the walls that hold up my deck slab. My engineer suggested that I needed 12mm bar at 400 centres both vertically and horizontally (like in blockwork walls). I was going to place the vertical bars first (sticking up out of the footing) and then just fix the horizontal bars as the wall got higher. This way I could walk through the vertical bars to access both sides of the formwork. The problem that stopped me using this method was that the building inspector wanted to see every bit of reo in place so they would literally have to watch as the wall went up (or I would have to wire up all of the bar for the inspection and remove/reinstall it later). In the end I gave in and just changed these walls to poured earth/concrete. I'm certainly not suggesting that you change your construction method (as I much prefer the rammed earth) but just giving you some thoughts to consider.

I would also make sure that I angled the top of the tamper away from the mesh as I would not like to get my trigger hand jammed under one of the horizontal bars of the mesh when it bounces up. :shock:

Quote:
I've been reading Bluey's thread with keen interest since his requirements are very similar to ours, so I hope he doesn't mind if I end up stealing some of his ideas


I would be more thatn happy for you to use my ideas. Just note that I have not had any of the shutters inspected as yet so I will let you know if that brings up any issues you need to be aware of. There is always a risk of difficulties arising when you start to head down a non-standard path.

Bluey


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PostPosted: Sun Feb 19, 2012 2:42 pm 
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Bluey wrote:
I think that mesh will be ok to work with as long as there is enough space between the mesh and the formwork. ... If you are using the Bobcat to lift the mix into the forms you will not have room to tip the bucket straight into the forms as the mesh will get in the way. You might need to tip the soil onto a platform first and then push it across into the forms (or use buckets, shovels etc to manually lift it in). I'm sure that you will come up with a solution.


I've been thinking about this, and what I think I'll do is make up a platform / chute of sorts which can clip over the top of the forms at something like a 30º angle, and empty the bucket into that. It'll work at least for the lower levels, within reach of the bobcat. Above that I think we'll be working with buckets on ropes :lol:

Bluey wrote:
The other difficulty is that the mesh will form a barrier between one side of the forms and the other. When you pour the mix in you can compact on one side of the mesh and you will then need to walk/climb around to the other side to compact the rest of that layer and repeat this for every layer.


Yeah, there's no disputing the fact that the reo is going to be a pain in the arse but it's a necessity so something I'm just going to have to work with.

Bluey wrote:
... the building inspector wanted to see every bit of reo in place ...


So far our inspector has been pretty easy going - we've shown him what he wants to see, and that's been that. I'll probably get him out to look at the first rammed earth section with the full complement of reo in place, and then hopefully we can just get on with the rest on the basis they're all the same. Either way, it helps that he's local too - he lives at the end of our road at the bottom of the mountain so he can come see whenever he likes ;)

When it comes to constructing the walls, we're required to install a control joint every 3m with a 100x50 mortice-like joint so that will dictate the size of each panel. The other thing is that the engineer "recommends" (but does not require) we taper the wall from a 400w base to 300w at the top, but I actually think this will complicate the build considerably and I'll produce a higher quality (and therefore stronger) job if I keep the walls parallel. I think I'll clarify that with the engineer, just to be on the safe side...

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The adventures of an owner-builder in the Tallarook Ranges


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 Post subject: 3D
PostPosted: Sun Feb 19, 2012 3:34 pm 
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(Crossposted from http://tallarook.cocking.id.au/post/17871209763/3d)

Shortly after Peter drew up our working drawings last year, I started work on a 3D model of the garage & unit in Google’s free Sketchup tool. This is a brilliant program, not quite CAD but brilliant for conceptualising pretty much anything in 3D. Google use it to model cities in Google Earth, to give some depth to their 2D satellite imagery.

Anyway, the process of drawing up the design has been invaluable - I’ve managed to spot a couple of details in the design which look fine on paper, but don’t quite translate to something structurally intact in the real world. One example of this was the upper suspended slab - because we have the stairwell in the corner of the slab, one portion of it was effectively unsupported and cantilevered over the concrete block retaining wall. Not good :)

The great thing about producing the model is that I can catch these little gotcha’s before we get anywhere near making the mistakes on site where they’ll cost $$$ and time. It also allows me to produce accurate estimates for materials too - I can visibly see how many Hebel panels we need, how much timber framing we’ll need, etc. meaning with any luck we’ll save some money by ordering only as much material as we’ll need.

Anyway, pictures tell a thousand words:

This is where I’ll be spending most of my time (with any luck!)

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A kookaburra’s eye view of the unit from behind, overlooking the patio above the shipping container.

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A few layers stripped back, showing the roof construction. The jack trusses and rafters in the garage not only provide a good up-and-over profile for a passing fire front, but conveniently I gain some clear space under which to install a two-pillar car hoist, for working on my Minis (and the odd Hilux).

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More roof stripped away above the unit, showing the floor plan. On the south side of the building we have the two bedrooms and bathroom, then a central rock wall for internal thermal mass in the living space. The eastern-most part of this area will initially be fitted out as a kitchen, but thanks to planning regulations this will be removed once work is completed on the house proper, in order to classify the unit as dependent on the house and not self-sufficient.

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This one shows the ground floor layout. At the front of the building we have the pump room, which will house our petrol fire pump which will also be used to pump water from the collection tank(s) around the garage, up to our main header tank at the top of the hill. We’ll do this every couple of weeks, primarily so we know we always have a working fire pump - so many stories emerged from the Black Saturday fires of fire pumps failing through disuse that we’re not going to fall into that trap.

Beside the stairwell will be our power room, housing batteries, inverter and controller for the solar system.

Behind that is a clean / wash room, so we have somewhere away from the dust and grime of the workshop. Then the container, which will serve duty as a store room.

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Simon.

The adventures of an owner-builder in the Tallarook Ranges


Last edited by sgc on Mon Feb 20, 2012 6:51 pm, edited 1 time in total.

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PostPosted: Mon Feb 20, 2012 6:40 pm 
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Location: Blue Mountains
Simon,
Quote:
I actually think this will complicate the build considerably and I'll produce a higher quality (and therefore stronger) job if I keep the walls parallel.

I agree that life will be easier for you if you do that.


I like the sound of having your firepump set up so it is in regular use. Might have to come up with something like that for mine.
Bluey

PS For some reason I am not able to see the pic's in your last post or on your linked blog page??


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PostPosted: Mon Feb 20, 2012 6:45 pm 
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Bluey wrote:
For some reason I am not able to see the pic's in your last post or on your linked blog page??


Heh.. I was wondering about that. Grabber on the Mac saved the files as TIFFs and I forgot to convert them. Works for me, but obviously not everyone.. will fix.

Cheers,

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Simon.

The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Mon Feb 20, 2012 6:52 pm 
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sgc wrote:
will fix.


There.. try that :D

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Simon.

The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Mon Feb 20, 2012 7:42 pm 
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That's better! :)


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PostPosted: Tue Feb 21, 2012 9:08 pm 
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Been spending a little time in Sketchup in order to model a few of the finer details of the work I'll soon be undertaking. Taking inspiration from Bluey's rammed earth, here's what I hope I'll end up with in our garage:

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2.0m long by 2.5m high panels, core reinforced with RL918 mesh. A few things to get done before I can make a start on these, but I'm lining up my ducks. I have a pneumatic tamper on its way from the US, and a kick-ass air compressor to drive it coming from Ballarat (my little dinky Supercheap Auto jobbie is way too small to do the job, so this one is a petrol-powered, 42CFM three-cylinder with a 150L tank. Should be big enough ;) )

Just gotta get this blockwork retaining wall out of the way first...

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The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Wed Feb 22, 2012 10:44 pm 
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After Bluey very generously shared his rammed earth formwork designs, I've spent a few hours in Sketchup, putting the design together for my own forms. They're based heavily on Bluey's, primarily because it's clear from his results that they work pretty well and there's no point reinventing the wheel!

Bluey you're a legend, thanks for sharing! 8)

Here's what I've come up with. I'm going with the internal bracket idea, it's too simple and elegant ;) Here they are, bolted 2m apart:

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Then the columns are bolted to these and plumbed using Bluey's method:

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Then the form panels installed:

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Magically, the Rammed Earth Pixies do their stuff and a wall appears! :D Ideally I'd like to be able to lift the one set of form panels up the wall as I go rather than build a second set and stack them, but I'm not sure whether the wall will have enough strength before it fully cures to support the ramming above without deforming. Bluey, what say you?

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The forms are then set up leaving a 2m gap and another panel rammed. Then the forms bridge the gap without needing the columns:

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It'll be a month or so before I get stuck into this part of the build, but hopefully by then I'll have thought out (and drawn) all the problems :)

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Simon.

The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Thu Feb 23, 2012 2:42 pm 
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Ordered the steel for the rammed earth wall and the upper suspended and on-ground slabs today. Per Angelis' suggestion I tried to order it galvanised, but apparently it's not supplied that way so I'll have to get it done myself.

A plug: If anyone in central Victoria is in need of reo steel, give Mark a call at WB Hunter in Shepparton (03 5821 5744). Good service, and even better prices :)

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The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Sat Feb 25, 2012 8:54 pm 
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Fairly productive couple of days on site this weekend. After doing my extra Sketchup modelling during the week I decided to remove the first 2/3rds of a course of blocks I laid last week, since the starting position of the first rebar was wrong and over the length of the wall, the bars began to foul on the block webs.

After altering my starting position (so now there's only one bar out of place) the first course went down without a hitch. Sure does take longer than you think it will though - it was 10am by the time I started mixing mortar, and 6pm before I finished the first course.

So this morning I got stuck into laying the second course, expecting this one to fly by but .. it doesn't matter how careful you are and how many times you check the level, something always stuffs up. Quite a few blocks in the first course had shifted ever-so-slightly (probably when I set the block next to them) so I ended up adjusting the level and position of the second course tirelessly.. it probably took between 5 and 10 minutes to lay each block by the time I cleaned the beds of debris, placed the block, checked the level, tweaked the level with plastic wedges, checked again, adjusted the block next to it, checked again, etc etc.

Good result though:

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I also used up my stock of N12 rebar to place and wire most of the extended vertical stems. I'm not looking forward to having to heft the blocks 2m into the sky and over these bars next week though... gym? Who needs a gym? :lol:

In other news, this behemoth showed up, another eBay score:

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It's bigger than it looks in the photo - the tank is about 1.2m long :shock: 15 HP petrol motor, 42CFM free air delivery (not sure I believe this, but we'll find out in a few weeks) and loud!! :lol: I don't think it's going to struggle to supply my rammed earth tamper...

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The adventures of an owner-builder in the Tallarook Ranges


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PostPosted: Sun Feb 26, 2012 10:10 am 
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Congratulations simon and family
Great blog , along with blueys thread i will be following with great interest.
Tuesday we plan to place our slab for our own RE building.
It has been many years in the planning , hoping to start ramming asap :D


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PostPosted: Sun Feb 26, 2012 12:21 pm 
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Nice tidy work Simon.

I have a couple of toys that came with those smaller 12 volt batteries and I'd suggest you have a backup for them in place. My hard learnt experience is they don't last long. I carry a multiple battery setup in my Ranger (http://ayresrocks.com/blog/rip-trusted-workhorse/ ) to guard against this and simply plug a battery into the smaller 12 volt using 50amp leads with smaller of the anderson plugs.

Nothing more frustrating than travelling to site to find your toys won't start :)


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PostPosted: Sun Feb 26, 2012 3:28 pm 
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angelis wrote:
Nice tidy work Simon.

I have a couple of toys that came with those smaller 12 volt batteries and I'd suggest you have a backup for them in place.


Thanks! It's surprising (to me, at least) the level of precision required when placing these blocks. Since there's no mortar other than the first course to take up any level adjustments, it's extremely important to get the blocks perfectly level if the wall is going to be straight. It's a fiddly, slow job...

As for a backup for the batteries, I hear you :) I have one of China's Finest diesel generators, and it's got a little battery in it which is just shy of adequate. It'll turn the engine to compression at TDC, but it doesn't have enough grunt to spin one full cycle and stalls. I've rigged a wire up to the decompression lever so I can get some inertia up in the crank for a few cycles, before allowing it to fire.

My backup is either the Hilux - I have an aux. battery in the back under the tray, or the bobcat which has a thumping great 1000CCA battery in it - the biggest I could buy which would fit. I don't go anywhere without a set of jumper leads :lol:

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The adventures of an owner-builder in the Tallarook Ranges


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