Door #2

I managed to get the second door hung today and magically, it fits perfectly!!

It was a tense moment or two after I screwed the hinges in place and swung it closed for the first time - I was waiting for the bottom of the door to scrape on the slab rebate - but it closed perfectly, with a nice even gap to the first door top to bottom.

Thrilled with that!!

This door has a covering angle to seal the two doors against ember entry.

It's not finished yet - I've found with the first door that the rivets aren't strong enough and tend to break and pop off, so I've got the sheet steel "tacked" in place with a few rivets, and I'll purchase some steel button screws during the week and replace the rivets with these.

I've yet to decide how the doors will latch during regular use. I'm going to use drop bolts top and bottom to lock them, but when they're in daily use I'll need some way to latch them without locking them. I'm thinking I'll set up a few strong magnets in the ply backing; I have some here which are only about 2cm x 1cm x 1cm in size but have a clamping force of about 100N, so a few of these should be plenty to keep the doors closed in the strongest wind.

I'm also not convinced that my hinges are strong enough for the job, especially since I've yet to line the inside of the doors with ply. I'm constructing these doors to exceed the BAL-FZ design requirements for the roof - an insulated steel/ply sandwich construction - and the 18mm ply will weigh about 40kg on each door (which are probably already 50kg each). I'll aim to get these ones finished first, then decide whether the hinges are up to the task before I hang the second set.

Garage doors - slow going!

Damn, these doors are taking lots longer than I'd hoped...

I spent the whole day today finishing the steel cladding on door #1, welding on the hinges and hanging it.

I really had no idea how well it would fit - I made a bit of an allowance for the hinges and clearance in my measurements, and stuck to them pretty closely when I put the doors together - but to my immense relief it fits pretty bloody well!

It's slow, fiddly work though - and heavy, to boot. I've used 4 heavy hinges but I'm not convinced they're heavy enough. Time will tell whether or not the doors sag in the middle but for now I'm very happy with the fit. They'll even fold back perfectly flat against the wall - a lucky accident as it happens; I hadn't designed for this!



I'm not terribly thrilled with my chosen method of attaching the steel facing though - I'm using aluminium pop rivets, but I think I'll drill them all out and replace them with steel button head screws instead. The rivets hold OK when they're first fitted, but I can see that they'll probably weaken over time and its anyone's guess how they'd perform in the face of radiant heat. So it's probably wise to err on the more substantial side...

Septic is in!

A biiiig day today - the septic system and outflow lines are all in.

Savva brought in an excavator to do the digging - and boy, am I glad he did. At one point some time ago I toyed with the idea of digging the trenches myself, but after today I realise that would have been:

a) Totally, unbelievably, inconceivably, futile; and

b) Pretty bloody dangerous!

On his excavator, Jeff had little trouble manoeuvring on the terrain but the rock!! There are rocks he had to pull out of the ground that I doubt the bobcat could lift, let alone dig up. My job was to run around with the bobcat moving gravel, and even that was a bit fraught at times. With a full bucket on flat ground I could only just lift it off the ground before the back wheels lifted; facing downhill it didn't take much at all to tip it over. So I spent most of the time driving around backwards - backwards downhill, backwards uphill!

On a couple of occasions I nearly put the bobcat nose first into the trench - I had to turn to face downhill to empty the bucket, and with too much weight in front (and the occasional rock under the rear wheels) all the machine wanted to do was tip over. It's heart-stopping and looks pretty spectacular, but ultimately it's safe enough - all I have to do is drop the bucket and drive backwards, and it rights itself.

What's not so easy is driving out of a hole. Just once I reversed into one of the pits, and put the machine over on a 45º angle; with two wheels flying in the air there was no getting out of that myself. It took a nudge from Jeff's machine to get out of that one.

No, I didn't get a photo! :)

Speaking of photos, I'll let them do the rest of the talking. Check out them rocks!

All up 180m of trenches 1m wide, and 5 truckloads of gravel in the ground. Now all I have to do is fill the tank with water so it doesn't float out of the ground...

Solar progress

With the wiring proceeding apace and the garage rough-in (and fit off, since I'm not lining the walls) likely to be finished this Friday, I'm getting ready to pull the trigger on the solar system components.

I've got prices for the batteries down to "Who's quoting you that, it's below cost!" levels, and today I found another supplier of my chosen solar panel who will sell them to me for $25 each less than the next best (provided I pick them up from the importer directly). No problemo! :)

So that now leaves me to figure out where all the components are going to live.

Firstly, the solar panels. In consultation with Nenad and after observing the roof's solar access and shading at the winter solstice, we've decided that the best orientation for the panels is (not surprisingly) due north. We had discussed splitting the array in half and pointing one half NNE and the other NNW in order to maximise the morning and afternoon sun, but I can't really find a way to make all the panels fit on the roof in a way that looks any good, and is easy to do electrically.

So, due north it is.

The other bit of modelling I've been doing is designing a battery enclosure, now that I've settled on the brand and type of battery. Because flooded lead/acid batteries produce oxygen and hydrogen gas when they are charged, the batteries must be vented to the atmosphere to prevent the possibility of a rather nasty combustion event. Electrickery plus explosive gas equals ... an expensive insurance claim!

The original intent was to vent the battery box naturally by ducting it to the holes I had bored in the retaining wall, but according to the regulations those holes give us about 10% of the surface area we'd need to vent the batteries at the charge rate we can sustain. Rather than run a big duct out through the pump room, it's on to plan B: Forced ventilation.

The SMA inverter/charger I'm using has a neat feature - battery room fan control. When it detects that the batteries are gassing (through a combination of temperature sensor and knowing the charge current) it can switch on a fan to ventilate the batteries. According to the regs I "only" need to provide 20 litres per second of airflow for the 140A charge current we can potentially deliver (even though we'll struggle to generate 100A between the panels and generator) and I've managed to source some tricky little 240V fans (like the ones in a computer) which only draw 4W each, but use that to move about 18 litres of air per second. So I'll mount two of these on the outside of the enclosure blowing in (important detail that - it wouldn't be a good idea to have them sucking the gas out, as any sparks in the motor would trigger the above insurance event) and duct the box out through the holes in the retaining wall.

There's still a bit of juggling to do with the location of the box and inverters, to make room for switch boards but this is roughly where it'll all live.

Tank stand #1

Today's job was to build the first tank stand in behind the shipping container, to catch the bulk of the rainfall from the garage roof. First though I needed to route the drain from behind the retaining wall, as the tank will basically go right over the top of it.

Half an hour or so on the bobcat and presto, one trench.

Filled with gravel, and measuring up for the sleeper-on-ground frame:

To join the sleepers together I've cut lap joints with the chainsaw, and spiked them together with a 30cm length of 12mm reo bar.

I've used star pickets driven into the ground to keep the sleepers in position, and then filled between them with the 20mm crushed rock, screeded it level and ran over it with the vibrating whacker.

Voila, one tank stand!

With the rest of the truckload of gravel, I spent some time spreading it out in front of the garage to try and keep it from turning into a bog. I didn't notice at the time, but I must have just tapped the Hebel with the back of the bobcat, as there's a slight yellow smear right by the damage.

F#&^@#$%&#^K!!!

Today's progress

I arrived late last night as usual, and in my auto-pilot daze nearly ran into this!

I had been trying to get a load of crushed gravel up to the site for about a month, but it's been just too wet for the trucks to get back out and so with the weather being dry all week I was hoping to see the truck arrive today.

Much to my surprise, they delivered it yesterday!

Thatsalottagravel! :)

This will go to good use this weekend - tomorrow morning I'll get the rear tank stand set up with a frame of old railway sleepers, filled with this stuff and hit with the whacker. The rest I'll spread out and compact down around the front of the garage and the steepest section of road so I can get more trucks in next week.

So today I had both the plumber and electrician on site - Savva the plumber to finish all the little fiddly flashing details, and begin installation of the solar hot water system, and Nenad the electrician to complete the upstairs wiring rough-in and make a start on the garage.

I spent the day apprenticing for both, and managed also to assemble the frame for the hot water system's evacuated tubes:

This thing certainly isn't very subtle!! It's on the south facing slope of the roof, mainly because there are so many tall trees to the north that if we placed it on the north slope it would be shaded too much of the day in winter. Today being the winter solstice, the sun didn't hit the tin until 10:30 at the earliest! So having the tubes sited further back away from the trees means it'll pick up more of the sun in winter.

I've set it up at about 50º to the horizontal, meaning the frame is set up at 65º to allow for the 15º down slope of the roof. Our latitude is about 37.5º south so that's roughly the angle of elevation which gives the best average performance year round, but we'll need more out of it in winter than in summer so it's angled more towards the winter sun for better performance in the cooler months.

So the outcome today is that the flashing is all but finished with just one fiddly little bit left to do, underneath the window in the north face of the garage roof. The solar tube frame is installed and securely bolted down, and the plumbing up to it is in place. All we need to do now is install the tank, pump and gas booster, then run gas down to the position of the bottles. Oh, and dig 350m of trench up the hill to the header tank site...!

The electrical install is coming along - the rough-in upstairs is complete, and most of the power wiring is in downstairs. Next week we'll finish that off and get the lighting installed in the garage - I'm hoping to fit off the garage as soon as possible as it's not going to be lined - so that I can install the solar panels, inverters and batteries and actually commission the garage at least. I'm so looking forward to having power!!!

On that point I've been playing with options for siting the solar panels. With the surrounding trees we've got a serious shading problem in the morning, so it's looking sensible to split the panel array in two (easy as my chosen inverter has two MPPT - maximum power point tracker - inputs) and face one half to the north-east for morning sun, and the other to the north-west to pick up the afternoon. As a baseline however, I've begun by drawing up the array facing due north so we get an idea of how it will work with the roof space:

We almost certainly won't install them this way, but it does show at least that we can fit 16x panels in a pretty tight space!

I alluded just before about getting more trucks in next week - if the weather remains dry, Savva is going to try and get the septic system installed on Thursday. This is going to require about 180m of trenches, 1.0m wide, at least 400mm deep - that's over sixty cubic metres of gravel! It'll take at least 7 or 8 trucks to deliver that much, so I want to make it as easy as possible for the drivers to get in and out so I'm thrilled to have my crushed rock on site finally!

One faulty window

I noticed this a week or two ago and have been trying to get a good photo of it ever since, to present to the window company.

Basically, the large upstairs fixed double-glazed window unit has two problems:

1. It's not been installed properly. One corner isn't seating against the frame correctly and there's a gap tapering up to 5mm  in the corner. Because the double-glaze edging is black you probably wouldn't notice this unless you were looking for it, but from outside it sticks out like the proverbial because the beading strip is very obviously not straight.
2. Right in the middle at eye level, there are a handful of white dots on the inside of the double glazing. It's as if there was a couple of droplets of a liquid between the panes of glass and when they were separated to form the double glazed unit this has dried into a set of very visible dots at the same point on the inside of each pane of glass.

I could live with the installation problem, and I could live with the dots if they weren't smack bang in the middle at eye level... but I can't live with both. So this week I fired off the following photos to the supplier with a descriptive email, asking what we can do about them. I honestly didn't expect much - I thought I'd get an argument and shifting of blame.

In a massive surprise the rep didn't bat an eyelid and promised to have the unit replaced, no questions asked!

(Excuse the poor quality photo's - my proper camera was out of batteries, so these were taken with my phone!)

This was the easiest way to show the dots - force use of the flash and stick a sticker to the window to give the lens something to focus on.

If you squint you can see the beading tapering out as it gets higher. I promise!

So anyway, the supplier is going to send the original installer (as this pane was subcontracted out) back out to remove this pane, take it away and rectify it, then reinstall. Can't ask for better service than that!

A little bit of purchasing action

Since yesterday three of my four solar component decisions have changed, or changed supplier. I've locked one in as I just ordered:

1 / SMA Sunny Boy 4000TL panel inverter;
1 / SMA Sunny Island 6.0H inverter/charger; and
1 / SMA Sunny Remote Control

from the friendly folks at TCK Solar for the grand total of $5,797 inc. GST. They're nearby in Brunswick, so I'll save a little on shipping by picking them up myself.

Next up I think I'll pull the trigger on the solar panels once I have a chat to the installer about what I'll need to mount them.

The other change is that I think I'm going to go with a different battery. The supplier I've been talking to about these Surrettes has now done an about face and reckons they're no good for full-time off-grid use - or more accurately, they won't last as long as they should in this use case and that they're more suited to a weekender.

That's OK - I was starting to lean in another direction; using 12 x 6V 1600Ah Exide batteries in a single string instead, rather than three parallel strings of 8 x 600Ah Surrettes. Easier to set up, and fewer cells to go bad even if it does mean I'm 200Ah poorer. But hey, I'd probably lose that in the additional wiring anyway.

So it seems he's talked himself out of a $15,000 sale while trying to talk me into spending $25,000.

My next dilemma is going to be how and where to take delivery of 12 x 120kg batteries!

Solar's doing my head in

I'm in full-on negotiation mode at the moment, searching out the best prices for all the components we need for our solar system. I'm keeping track of it all in the World's Biggest Spreadsheet but seriously, my brain is going to burst soon I'm sure.

So far I'm looking at:

16 / Simax 250W monocrystalline solar panels - $245 ea from Low Energy Developments
24 / Surrette S-600 6V/600Ah lead-acid batteries - $597 ea from AtoZ Batteries
1 / SMA Sunny Island 5048 5kW inverter/charger - $3993 from TCK Solar
1 / SMA Sunny Boy 4000TL 4kW panel inverter - $1573 from SolarMatrix

Total so far for the components - $23,274 delivered, including GST.

Still to add to all that are AC and DC switchboards, mounting hardware for the panels, a vented battery box (which I'll build myself), wiring and fuses. Call that another $2,000. Then add another $1500 or so for light fittings, power points, switchgear, etc. With luck I'll see the whole thing installed for under thirty grand.

This gives us 4.0kW of panels (call it 3.0kW after transmission and conversion losses) and around 2.5kWh/day of battery capacity before we need to start the generator (10% discharge on the battery).

Geez, I hope that's enough!

At some point soon I need to stop thinking about this and start doing. The trouble is, the more I keep digging around on the Internet the better the prices I find. It's hard to know when to stop...

At least this week the weather is looking good - after about 4 or 5 weeks waiting I might actually finally be able to get my load of crushed rock delivered so I can get on with my tank stands. Friday should see a frenzy of activity - Savva the plumber should be on site to finish all the flashing and get a start on the solar hot water install, and Nenad the electrician will be back to complete the upstairs wiring rough-in and get stuck into the garage.

Then I've got stair treads to cut out of sleepers, garage doors to weld up clad and mount, tank stands to build, trenches to dig for water plumbing, water tanks to order and install... at least the days are going to start getting longer soon! Gotta look on the bright side :)

A little experiment with stair treads

We've been tossing ideas around lately as to what to do about stair treads from the garage to the unit above. The stair well is only 1.0m wide and enclosed on both sides, so the stairs will be as simple as they come - timber treads supported at each side by brackets affixed to the walls.

I had originally looked at some redgum slabs which were absolutely beautiful but at $1500 for 14 treads, a little outside the budget. The latest idea is to use old railway sleepers, which at between 2.4 and 2.7m long and around 120mm thick, will yield four treads per sleeper nicely.

I picked up some decent A-grade sleepers for nothing today and decided to see if I can cut them on site with a chainsaw.

Even with a freshly sharpened chain it's seriously slow going; these are either grey box or ironbark sleepers and the timber is old and hard! Perseverance pays off in the end however:

The timber needs plenty of dressing with a plane and belt sander, but I think they'll make fine treads with plenty of character. Best of all, they're cheap! If I have to buy A-grade sleepers, I'll still only pay $10 per tread. Can't beat that!

Wiring, round #1

I had the electrician on site today to begin roughing in the wiring. We started upstairs since during the week Alissa & I managed to put together a good wiring plan, identifying all the spots we want power points, lights, switches, etc.

The wiring is all very conventional 240V - but I intend to use some very clever lights and other bits of technology. More about that later ;)

We've managed to get all the power in, all the lighting feeds and two runs out to the lights. There's a little more switched lighting wiring to go, maybe another hour or two's work and it's all done.

I still need to run data cabling around the place - I'm commandeering the top shelf of the linen cupboard and installing a patch panel and power points, so I can keep all the networking gear out of sight. I'll do that next week I think while Mr. Spark finishes off the lighting upstairs.

I'm running out of things to do upstairs now before we can begin lining the walls and ceiling... a good problem to have! :)

(Now, don't talk to me about the weather.. I've been trying to get a truckload of crushed rock onsite for the last three weeks, but it keeps raining!)

I'm also getting pretty close to my final solar system design, and I'm currently working the Internet hard to find suppliers of the various components. So far I've got the battery bank down below $10k, and solar panel prices down to around $1 per watt. I just need to find a sharp price on the SMA inverters, and I'm ready to push the 'buy' button!

TWO garage doors, ha-ha-ha!

Feels like I'm getting the hang of this welding caper! :)

I need to have a think about how I'm going to finish the steel facing. I had planned to wrap it around the frame to be covered by the internal ply lining, but it's too thick to bend easily and although I've massaged one corner into it I'm not terribly happy with how it looks and so I'm considering my options. I think it'll look better if I just cut it flush with the frame.

In any case, I need to figure out what hinges and other hardware I'm going to use this week so I can get these doors hung on the weekend. I will get locked up soon!

ONE garage door, mua-ha-ha-ha!

Today I finally made a start on the garage doors. I had planned to spend some time last night drawing up the steel frames in SketchUp, but I wasn't confident in my measurements of the frame opening and so I waited until this morning to re-measure (they were correct) and draw them up:

With my cut list finally worked out (it took all morning!) I finally set saw to steel around midday and cut all the pieces for two doors. It took about 4 hours of measuring, cutting, assembling, measuring again, grinding and trimming, measuring again, tack welding, measuring again and finally welding everything together to achieve this:

One door, 2.7m high by 1.7m wide. And whaddya know, all that measuring appears to have paid off as it looks like it'll fit! :)

With daylight rapidly diminishing I decided to keep ploughing ahead and cut a sheet of gal steel to fit, and started rivetting it on.

Since I have all the steel for the second door already cut, I should be able to get it assembled tomorrow and finish this one off, and if I'm really efficient I'll also get the timber frame in place in the second opening!

Yeah, right... :)

A-welding we shall go

I spent the day today finishing off the little stand for the hot water service tank. In my usual style I did a little SketchUp drawing first so I knew what I was doing:

I then cut all my pieces out of 30x30x2 galvanised tube and got set to start welding.. until i realised that this is going on the flat roof over the pump room, which is pitched at 1.5º. As drawn, that tilts the tank over at 1.5º too.. which is not what we want!

I'd already welded up the legs by this time and after stuffing around trying to build up one side of the legs with weld to extend them (because I hate starting the generator so I can run the chop saw) I saw reason and .. started the generator.

A little cutting, welding, grinding and spraying later, and voila!

This will have a piece of checkerplate steel tack welded on top to finish it off, and evenly support the ~400kg load of the tank when full. According to my Swiss Army Phone, I've got about 1.6º pitch on the frame, which is close enough.

As an aside, I discovered that Hebel makes a fine surface on which to weld with the oxy torch. I've done some welding (well, oxy cutting actually) directly over the concrete slab and discovered that it doesn't like that very much at all, and blisters and explodes in protest. The Hebel on the other hand, just glows orange and ignores it until it stops and I accidentally touch it, when it bites hard! I can see myself making up a nice little bench using this stuff once I get to inhabit the garage.

I spent the rest of the afternoon installing the timbers for the garage door frames. I had a quote from a supplier of fire-rated steel door frames during the week, but they wanted $1,200 each (!!) for the 2700x3500 openings, so I've decided to install timber door frames using 140x35 KDHW and flash them with steel sheet just like the window frames. Much cheaper.

So with one opening fully framed and I now know my exact dimensions, I can draw up the door frames in SketchUp and get stuck into them tomorrow.

Still wet :(

I did manage to grab some old railway sleepers last week, but that's about all I got done. The rain never really let up, and the ground around the garage is positively saturated to the point that I sink up to my ankles if I try to walk across there.

Needless to say there's no point getting the bobcat out to sort out the tank stands.

All my anti-rain-dancing has had little effect too - we had a torrential downpour in Melbourne last night and about half that at Tallarook, so again the ground is a mucky wet mess. I've had to call off the gravel delivery a second time, so there will be no tank stands being built this weekend.

Instead I've been busy fabricating up a stand out of 30x30x2 SHS steel, for the solar hot water tank. I picked this up yesterday and it's now all on site, and we're about $4500 lighter.

It's going to be an expensive few months...

Savva was on site again today to finish off the roof flashing, or at least to attempt to. Although I've ordered all the flashings as per the designs in the Hebel manual, Savva is finding them a pain in the arse to work with and so we're going to modify them slightly so they're more .. conventional. This means I have to get some more sections bent up, but I needed to anyway to finish off the flat roof above the pump room.

If the weather holds we'll get the septic tank and trenches installed in a couple of weeks. Good news!

The other positive outcome today was that I met up with Nenad the solar electrician, and we had a good long chat about the project and what I'd like to do. To my considerable surprise he's never installed an AC-coupled system before, but he's got an open mind and for comparison's sake he'll go away and design a more conventional DC-coupled system and if it's cost competitive with what I can source, we'll thrash it out. My suspicion however is that it's going to be quite a bit more... but we'll see.

Whichever way we jump with the design, he's going to start roughing in the 240V wiring next week (yay!!) which means I need to extract a digit and put together a wiring plan during the week. One positive which I'm very happy about is that he's more than happy for me to work as his "apprentice" and take care of the grunt work, which will bring down the duration (and therefore the cost) of the install significantly.

It almost feels like I'm beginning to make some progress! :)

So this weekend I plan to finish welding up the hot water service tank stand, then get stuck into the garage doors. If the weather holds I may even begin digging the trench for the main water pipe up to the header tank - this is about a 150-200m run, which I need to dig to at least 300mm deep through the trees beside the road. I wonder how much of a bastard this job will turn out to be...