More Hebel

With the families having headed back to Melbourne for a comfy bed and long warm shower, Gareth and I got stuck back into the Hebel. This time, rather than cutting three panels and erecting them, we decided to cut everything we need to finish one wall, move them and then throw them up one after another. This way we get to turn the generator off, which is a fantastic sound to hear.

We managed to figure out a pretty efficient system for moving and erecting the panels. From our stack next to the wall, we'd pick up a panel at each end, manoeuvre it so that its short edge is resting on the slab roughly in the correct position, then I relocate to the end that Gareth's holding and we both lift it vertical, adjusting its position slightly so as not to chip the back of the panel against the slab rebate.

There's a satisfying thunk when the panel stands upright against the wall, and when we heave it sideways to rest against its neighbour it thuds home, most often without a significant gap top or bottom. It's immensely satisfying, and never gets old!

There's plenty of cutting to do to fill in the gaps. Somehow or other I have managed to offset my door opening by 50mm or so - I think I've added a double stud for the opening on the wrong side - and so I'll need to make more cuts than I ought to to finish off the wall.

Next time I'll be more conscious of the Hebel installation requirements when setting out the positions of studs...

Monday morning saw the last of the Hebel go up for this weekend. With no safe platform to work upon  for the last of the upstairs walls, we turned our attention to the garage.

For this wall I decided I really wanted to see a completed window opening, so spent the extra time measuring and cutting the infill panels. The bottom section was easy to install by myself; however the top is ever-so-slightly too heavy to handle with one arm, and so I need to figure out a system of supporting it somehow while I screw it to the battens. I'll probably make up a timber frame the size of the opening, stand that in place and lift the infill panel up on top of it.

Or something. I'll figure it out :)

So that's where we finished up on Monday. With Gareth heading back home to Sydney and the day heating up, and with a few hours of cleanup, packing up and driving ahead of me I called it a day at lunchtime.

Next weekend I'll concentrate on cutting and installing the rest of the window infill sections, and then the following weekend Gareth has volunteered again to come back down (flying this time) to assist with the rest of the full panels!

Goodonya Gareth, your blood's worth bottling (or it would be, if it weren't full of beer! ;) )!!

Who doesn't love a bobcat!?

It is without a doubt the best investment I've made yet in this build, if for no other reason than the kids love it!

Australia Day Building :)

Every year on the Australia Day weekend we usually fire up the BBQ, chuck on the lamb (Sam Kekavic would be proud! :) ), tune the radio to JJJ's Hottest 100 and share some beer & ciders with friends.

This year being in the middle of the build, we thought "why not" and invited everyone up to the house site.

The half-finished dwelling made perfect shelter from the sun, and with the concrete floor and cross ventilation it was very comfortable! :)

It did put a dampener on the building works though.. hard to climb the ladder with a beer in one hand and the drill in the other! ;)

Hebel-ing!

It's been a long time coming, but we're finally getting the Hebel onto the building!

In true "House that eBay Built" fashion, I picked up this batch of Hebel PowerWall panels on eBay over a year ago. They don't come up very often - I've not seen them more than a couple of times since - but the seller had built a house and intended to build a granny flat, but changed plans and so had a stack  (155 to be exact) of panels left over.

They're not in perfect condition, and they've been out in the weather for a while now, but the price was right. Half price, to be specific :) There are few panels which don't have some damage, but there are very few which can't be patched up once they're installed. They're surprisingly fragile too, so even if they were undamaged to begin with they wouldn't be by the time they're installed, so it's no biggie.

The first panel to go up took a little while as it needed to be fettled a bit to clear the water inlet pipe, but the aerated concrete can be carved easily with a chisel so it's very easy to work with.

One problem though: The perfectly square panels are showing up my not-quite-perfectly square slab and frames. There's not very much in it at all, but the slab rebates are not quite perfectly square or at the same level over the length of a wall, so there will be a little "adjustment" required once the Hebel is all in place to get everything to line up perfectly.

Once we figured out a system and found our rhythm, the panels flew up in no time.

Contrary to the installation manual and possibly in error, we chose to skip the panels under and above the window openings for a couple of reasons. Firstly, cutting the panels is a slow and very dusty job and with the clock ticking on the adhesive, we chose to skip them. Secondly, the panels are exactly 600mm wide and the adhesive is not exactly 0mm thick and so the width of the wall section creeps slightly over its length. This means that the panels which should have lined up exactly with the window opening frames are a few millimetres long. By skipping the infills under and above the windows, we have the opportunity to "reset" to the correct position and the infill panels can just be cut to the size required.

Final Hebel prep

So in between the excitement this morning I managed to finish installing the battens for the Hebel panels along the side of the garage, before Gareth and family arrived. Surprisingly the wall wrap had survived the week in the wind, with only two small sections having broken loose; easily repaired.

Unfortunately with Gareth's arrival we spent the rest of the afternoon setting up camp (there may or may not have been beer involved, but I choose not to incriminate myself your honour :) ) and so very little additional building progress was made.

One thing I did during the week though was to pick up some 50x50x6 SHS steel. I noticed a while ago that the attachment plate I have for the bobcat has a couple of "sockets" welded to it, into which a square towbar tongue fit perfectly and so I decided they'd be perfect for makeshift fork tynes.

And perfect they are - I can easily carry three 100kg Hebel panels around without stressing the forks even a little bit, which is going to make the weekend's work of heaving these things around much easier. Unfortunately the attachment plate is 4' wide itself, so the tynes don't fit into a standard shipping pallet :(

How not to start your weekend

I was finishing my prep for this weekend's Hebel installation this morning, when I heard what sounded like a truck, or a car with a cage trailer coming down the main road - but then the noise stopped abruptly. That didn't sound right...

I jumped into the Hilux and trekked out to the road to investigate, and found this:

The road was strewn with debris and the four late-teen / early-twentysomething occupants were milling around the roadside dazed, one on the phone to the ambo's. One of the girls had a tourniquet on her elbow, hiding a nice 20c-sized gash but not bleeding much, and incredibly none of the others had any serious injuries, thanks to their seat belts.

I dashed back to the house site to fetch the medical kit and cleaner her wound up a bit, and very shortly thereafter a small army of police, ambulances and a tow truck descended.

Apparently the driver was doing "no more than 50km/h" around the bend, when the rear of the Hilux got away from him, he overcorrected, caught the embankment and barrel rolled along the road and down the hill. Now I know the road is quite rutted at the moment, but my Hilux is quite capable of 50km/h around that bend without spitting me off into the bush...

In any case, the four of them were incredibly lucky to escape without serious injury.

BAL-FZ detailing to Hebel wall panels

I spent a few hours in SketchUp last night working out how to detail the Hebel so that it interfaces with the roof structure in a way which is compliant with the BAL-FZ requirements.

The data sheet which details the tested and approved sheet roof system describes the roof to eave interface as follows:

However, we have no eaves or fascias in our design, with the guttering being directly affixed to the steel roof sheets.  So with that in mind I've adapted the design to suit our use of Hebel, retaining the ember-proofing elements of the approved system.

It turns out that the Hebel wall panels make the roof interface detail quite a bit simpler than if constructed using eaves as shown above. All I really need to do is ensure that embers cannot enter the wall cavity, which I achieve using 50x40x50mm Z-flashing, fitted to the plywood roof membrane and sealed to the top of the Hebel, which is cut to match the roof's 15º pitch. On top of this I'll install the Anticon roofing blanket as per the above design, and fill the void between the flashing and the first batten with Rockwool. All of this insulation will be compressed to roughly half its natural thickness by the tin roofing sheets, in doing so filling the ridges and troughs in the tin, completing the ember barrier.

The build-up to Hebel

This weekend it's been all guns blazing to get set up and ready to erect some Hebel panels next weekend, when Gareth and family are down for the Oz Day long weekend. Primarily this means fixing the battens to the outside of the frame to which the Hebel attaches, but like everything on this job it's never quite that simple.

First the battens actually have to arrive...

I ordered these from Bowen's on Wednesday, and was promised the second delivery on Friday after the first drop in Broadford first thing. 11:30am and no sign of them.. several phone calls later and "the truck's just leaving now".

Riiight...

Just as well I've got plenty of other things to go on with... first and foremost completing the installation of the steel angle brackets and plates to the half trusses and central bush beam.

The truck finally arrived at about 1:00pm, so I abandoned my chisel and hammer, and set about getting the dwelling ready for Hebel.

The Hebel PowerWall system is really pretty straightforward. To a typical timber or steel stud frame, you attach steel battens and then the Hebel is stood up against the battens in the rebate provided in the slab, and screwed from inside the building using Tek screws.

However, if you're installing sarking / sisalation (who comes up with these names!?) reflective foil "insulation" to the frame (and who wouldn't, these days) you can't screw the Hebel panels from inside the building because the wall wrap goes on before the battens, so you'd have to puncture the foil to place the screws, which defeats the purpose of the foil in the first place.

So, in this situation the Hebel is screwed from outside the building using f-off-sized bugle-head batten screws into the battens, and then patched over.

Anyway, before the battens could go on, I needed to wrap the building in this foil insulation. Normally you'd use little nail-plate tacks to fix the foil to the frame, but since I've got battens going on as well to hold it in place I just used a little staple gun.

Surprising (or not) just how long this takes... come the end of Friday and I've got half the building wrapped and battened.



Saturday was spent finishing the wrap and battens on the dwelling. Working at height with the staple gun and tek screws is really slow going, and my knees are really starting to feel the effects of the ladder.

It's starting to look like a building!! :)

The first job for Sunday was something I've been putting off for quite a while, and having done it now I'm not entirely sure why! When I excavated the footings for the garage, I just piled up the spoil at the side of the trench with the intention of moving it later. As with all good intentions, later never arrived but with the need to move freely with 100kg concrete panels fast approaching, sooner started looking quite attractive :)

So, in less than an hour this part of the site went from this (before Christmas):

.. to this ..

.. to this!

Damn, I love having a bobcat!!

So with that little job out of the way, Rhys and I set about wrapping and battening the garage.

And that's about where the weekend ran out. There's more than enough wall prepped and ready for Hebel next weekend, so now I need to spend some quality time in SketchUp and figure out the detailing between Hebel and roof in order to comply with the BAL-FZ requirements.

Back to work!

So things have been a little quiet around here the past couple of weeks, but not because I've been sitting idle - quite the opposite, I've just not had time to sit in front of the laptop and write! :) Being back at work and not on site full time certainly doesn't help...

This is where I left the building on the 6th. I'm pretty happy with how much I got done over the Christmas break! :)

The past two weeks have been spent making little visible progress at all. On the one hand there have been a couple of scorchers, which really make work impossible after about midday with the heat, but the tasks I've needed to complete are pretty much invisible anyway.

When we put the trusses up, we quite literally threw them up there and fixed them more-or-less in place, leaving the fiddly business of aligning and tying everything down to me, which are jobs which don't need the extra manpower we had available. So that's what I've been doing.

Firstly, all the bottom chord ties needed to be installed to space the bottom of the trusses accurately, then the truss noggs went in to space the tops. Then, the cyclone ties went on to fix the trusses firmly down to the wall top plates, and before you know it there's a day gone. Nailing with a hammer sure is slower going than using the gun...

Next up was working out a system to fix the trusses to the post & beam frames. The truss manufacturer simply specified universal trip-l-grips for this, but I'm not happy with these for a couple of reasons:

1. We've got these heavy duty, imposing logs holding up the roof structure, and using these flimsy little 0.8mm thick steel fixtures just wouldn't look the part.
2. The 40mm nails used with these grips would barely reach the hard heartwood of the logs, so over time as the sapwood aged the fixtures would weaken.
3. Big logs need serious fixtures!

So with that in mind, I've devised a system which will certainly exceed the tie-down requirements, and also look right against the imposing log structure.

For the trusses, I'm using 50x50x5mm steel angle, cut to 250mm lengths and bolted to the bottom chord of the truss using M12 allthread. The other end is fixed to the log using M10x75mm coach screws.

To fix the beam to the poles, I'm using 100x5mm mild steel plates cut 250mm long, checked in and fixed to the logs using M10x75mm coach screws.

I started cutting all 50 or so pieces of steel using the chop saw, but it was just too slow going and so I broke out the oxy set again and made short work of it all. Even so, half a day later... and I still have all the drilling to do before I can fit them all in place. I have a drill press here at home which will make it much easier than drilling hand-held with my cordless, so I've brought all the steel back to Melbourne.. hoping I can get it done before next weekend!

So in the meantime, I set about finishing installing the plywood to the dwelling roof.

No major drama's here, with the minor exception that after about the third sheet in the first row, the trusses are slightly off square which means the edge of the ply doesn't land in the middle of the truss properly, requiring a slight adjustment with the circular saw. This however means that the rest also need adjusting a little.. which is a royal pain in the proverbial. Lesson learned for the garage trusses: Make sure they're perfectly square and spaced accurately!

In any case, with perseverance and a day later:

Happy with that! .. although my knees are starting to object just a little bit...

Next day with the threat of rain showers I thought it best to protect the ply until the roof can go on, which won't happen now until the Hebel panels are erected. I have plenty of leftover concreter's plastic lying around, and so I dragged this up onto the roof, gave it a bit of a clean and secured it with roofing battens. These battens will remain in place permanently, and I think I'll just cut the plastic away when it comes time to install the Anticon blanket and roofing tin. Or not, I'm undecided yet. The approved BAL-FZ roofing system obviously doesn't include a plastic membrane over the ply, so for the sake of adhering to the spec I'll probably remove it.

So that's where I left it last weekend. When I'm back there's a metric buttload of work to do - my brother Gareth is coming down for the Australia Day long weekend to help out, and with his help I hope to begin installing some of the Hebel cladding which means I've got a lot of prep work to do in not very much time at all:

• Buy and install the sisalation / wall wrap;
• Buy and install the top hat battens for the Hebel;
• Figure out what / how much Hebel adhesive we need;
• Plan the set-out of the Hebel panels to minimise the number of cuts required;
• Finish the garage truss tie-down;
• Get plumbing services roughed-in to the cavity between frame and Hebel;
• Figure out what damp-proof / termite-proof course I need to use;
• Figure out how the Hebel is going to interface with the BAL-FZ roof system in a way which complies;
• Probably a dozen other things I haven't thought of yet.

So, business as usual then...

The LAST of the trusses!

As planned Jared and I finished notching the log over the shipping container for the last few full trusses, and lifted the two remaining half trusses into place this morning.

With plenty of fixing and fiddling to do, it was 11am before we knew it and Peter arrived to help erect the last of the full trusses.

Like a well oiled machine, we had the remaining 5 full trusses up in next to no time (or more accurately, 2 hours - it took me at least an hour to erect each truss in the upper level by myself) and before you know it, we've got a garage!!!

Now, I've been looking at and tweaking my 3D model of the building for longer than I care to remember so the result today shouldn't be any surprise, but when that last truss went up and I stood back to look at the finished product, all I could say was a solitary "Wow"! I sit here now at nearly 9pm and looking at it, all I can think is "Wow!"

Wow!

Pole raising, day 2

With the two poles and beam yesterday seen as a sort of a dry run for the real thing, this morning we got stuck into the serious business of erecting the central, feature, post-and-beam frame. The posts here are 2.5m long red stringybark (Messmate) taken from the 7.6m pole we retrieved from Jenna's place last week, and the beam is a beautiful straight bluegum log I felled (successfully this time!) some time ago on our property.

When we lifted the posts against the shipping container, we had a little insurance against over-balancing them - they couldn't fall forwards or backwards. The central poles however are free standing, and so we lifted them to vertical using the bobcat and ratchet straps, then off the ground for positioning over their bracket.

So first thing I began manoeuvring the first pole onto the slab, ready for its raising. Shortly thereafter, my brother-in-law Jared arrived from Wangaratta to help (at 6:30am, a serious effort after 4 hours sleep!!) followed immediately by Peter.

With pleasantries out of the way, we got stuck straight into it and lifted the first pole. This one we braced in two dimensions, across to the bottom plate of the wall frame which has already been securely bolted to the slab. This prevents the pole from moving anywhere, and gives us plenty of manoeuvring room on one side to raise the other two and the beam across the top.

With this one in place in record time, it was straight onto the second. I tell you, the bobcat makes this job an absolute cinch, and safe as houses. I'd hate to think how we'd have had to do this another way...

This one we braced again to the bottom plate of the external wall, and also to the top and bottom of the first pole. They're not going anywhere!

Next, the third:

Piece o' cake. All three poles in the air and it's only just gone 8am! :)

No stuffing around then, time for the beam! Being a shade over 9m long I'm unable to lift this one with the bobcat solo, so I used my castor-wheeled engine crane on the far end and pushed it around with the end of the log in the bobcat bucket.

One very slow and careful lift later, and bingo - we have one end of the beam in the air, in place on top of its pole.

(Please excuse the fingers over the lens, Jared is unused to iPhonery :) )

At this point we attached a couple of temporary vertical stays on the far post to prevent it from slipping sideways during the final lift, and another screwed to the end grain to prevent any chance of it coming off when tugging the log into position. Oh, and a little ratchet strap paranoia, too :)

So with everything prepped and ready, it's time for the final lift!

We took two bites at this one. When we first got the log seated on the poles we discovered how much error we had in our notching as the log pivoted on the middle pole, so it was lifted down, a few small adjustments made and then lifted into place permanently, all before noon!

With a forecast top of 38ºC and in the full sun fast approaching that, we took a short but welcome break for lunch and then got straight back into it. With two extra pairs of hands being so valuable, I couldn't pass up the chance to get some trusses up! I'd been wondering how to attack these by myself without a convenient hillside from which to skid the trusses up on, but with helpers they went up easily and quickly.

By far the slowest part of the job was the endless measuring, and the notching of the log atop the shipping container to take the ends of the trusses at precisely 2.7m high. In the end I ended up over-notching them a little; a little too deep and a little too low. The depth of the cut will never be seen, and the height allows the truss position to be fine tuned with precision packers :)

The truss manufacturers supplied 1.2m long cyclone ties for these trusses, and both Peter and I reckon these are fine if they'll never be seen, but with these trusses remaining exposed in the garage we'll be a little more industrial and use some 50x50x5 steel angle and big, chunky coach screws. Serious anchors for serious frames! :)

We pushed on despite the heat, and by beer-o'clock we'd managed to erect 10 of the 17 trusses in total. They still need to be fiddled with to find their perfect positions, but that's something I can do easily by myself without needing extra manpower.

So in the morning, Jared and I will finish notching the container log for the rest of the full trusses, and erect the two remaining half trusses before Peter returns to help with the last few.

It's been a very long, and truly epic day! By far, this is the most progress that has been made on site in one day and it couldn't have happened without the invaluable help of Peter and Jared. Thanks guys, you're both legends! :)