Monday, April 29, 2013

Installing the frames

I'm beginning to wish it was someone else doing this job, too...

I can see already that this is going to be a long and fiddly process. Normally, the window frames would be installed before the external cladding goes up, so that the cladding (brick, timber, Hebel, whatever) is cut to just the right size and abuts the frames neatly. However, a couple of factors (my own procrastination chief among them) meant that help was available (hi Gareth!) to erect the Hebel panels before the window frames went in, help which I couldn't refuse.

Two things about this are coming back to haunt me now:

  1. The Hebel is big, bulky and heavy and so cutting and installing it with any sense of precision is nearly impossible. Add to this the minor variations in the depth and width of the slab rebate and accumulating errors in my frame positioning and it's a minor miracle if the Hebel is within 10mm of its intended position.
  2. Despite my best efforts, the window openings in the stud framework are all ever-so-slightly different in dimension and plumb. No two are the same, and none are perfect. Add to this the problem of point #1 and in cases, the Hebel panel overlaps the window opening by as much as 30 or 40mm and is going to have to be trimmed in situ.
Now, with the windows all being sashless double-hung units the window frames themselves need to be installed with precision if the glass is going to stand any chance of opening and closing smoothly. In my (misplaced?) confidence I've only allowed 10mm clearance total (5mm each side) vertically and horizontally to the stud frame, so there's not a lot of wiggle room.


We began by oiling the frames, to protect them from the weather once installed. We've chosen (OK, well.. since I sent Alissa off to Seymour to buy it, she chose.. but she chose well!) to use a linseed oil-base coating which is virtually colourless, but very easy to apply quickly and promises to waterproof the timber. Just what the doctor ordered!

It doesn't show up as well in the photos as in real life, but the oil really brings out the beautiful grain of the timber. It's going to be a crime to cover it up with steel flashing...

With that final little bit of procrastination out of the way, I got stuck into installing the first frame on Saturday morning.

All of Saturday morning.

For just the first frame.

In fairness, a lot of my time was spent fart-arsing around with the Hebel, figuring out the best method of finessing it to size. I've tried (in no particular order):
  • A sanding float, with really course grit sand paper (from a floor drum sander);
  • A reciprocating saw;
  • A hand jack saw;
  • The circular saw with its diamond-tipped blade;
  • A chisel; and
  • A belt sander.

The sanding float is pretty good for finishing a surface, but rubbish at taking off large bits.

The reciprocating saw is quick enough (and can even cut through the odd reo bar) but its accuracy leaves a lot to be desired.

The jack saw is brilliant at cutting the panels (as long as there's no reo to get in the way) but it's horribly inaccurate (at least, on the far side where I can't see where the blade is going).

The circular saw is just plain bloody hard work; it already was when I was cutting the panels on the ground, but held vertically it's almost impossible (especially when standing on a ladder).

A chisel is remarkably effective at cutting the Hebel (again, reo notwithstanding) but it's woefully inaccurate over long distances and slow going.

The belt sander fairly rips through the Hebel with a course belt, although it creates monstrous clouds of silicosis-inducing fine dust which my mask does little to filter out. Oh, and it doesn't like rebar very much.

So, no silver bullet then.

I finally settled on a composite approach: Cutting the panel roughly to the right line with the jack saw (either vertically, or by making horizontal cuts to the right depth every centimetre or so, then breaking off the segments with a chisel) then finishing off with the belt sander.

Still, a royal PITA. It's not like we took any shortcuts with the Hebel either.. installing that was a hard slog in and of itself and plenty of attention was paid to getting it right.

Just not right enough, it seems...

Anyway. After several hours of fettling, frame #1 is in and as perfectly square as I can measure. It may not be perfectly plumb, but square is more important and I don't necessarily have the space to achieve both.

These are going to look sensational with the glass installed!

The second frame went in much quicker, the planets aligning so that little fiddling was required to get the frame in place and square. The third and fourth however were much tougher going; in one case I even had to deal with a piece of rebar vertically in the way by digging it out and cutting it where it joined to the horizontal bars. This promises to be the story of my life for the next few weeks, I think.

In other related news, after inspecting the doors which were part of this order, I think I've found a problem. The entry doors upstairs are double, inward-opening glazed timber doors, with the left-hand door (looking at them from outside) as the "lead" door. This means that the right-hand door will remain closed and bolted most of the time, and we'll enter using the left hand side. This arrangement is necessary primarily for ember and weather proofing - the surfaces where the doors meet are rebated and overlapping, creating a perfectly ember-proof seal.

Or that's what they're supposed to be.

It turns out that the doors are both "plain" edged - neither are rebated the way they should be. I've spoken to the manufacturer, and as soon as I mentioned the left-hand-lead the rep cut me off and told me he knew exactly what I was going to say. It turns out they have a worker on the factory line who's not been doing his job properly and they've had several cases of doors going out sans rebate, and so he's promised to get the doors picked up, rectified and re-delivered ASAP.

Even with this little fubar, I have to say I've been quite impressed with the service and quality of the workmanship these guys have delivered. Homeview Windows, via Bowens Timber & Hardware are well worth a look if you're in the market.


  1. Somewhere on youtube I've seen Hebel Block cut with a chain saw !!!

    1. Hebel blocks are a little different to the Power Panels I'm using -- blocks don't have any rebar in them! You can't cut rebar with a chainsaw... ;)

      The AAC material itself is really, really easy to work with - it can be cut with a hand saw, shaped with a chisel, a rasp or even a knife. It's the rebar which makes my job so much harder... :(