The resi building industry in Australia took a 30 year step back, good or bad?

Hey guys, you may like to see some detailed Sketchup models and how they are being used to push through the material shortages in Australia and, from all accounts, the rest of the world?
Carpenters are scrambling to relearn old school methods of pitching rooves and cutting frames onsite, so I made a video on why and when to chose trusses over hand-cut pitched rooves. I hope it helps you guys:

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I am not aware of the situation in your parts, shortage is here, too. I am not that present in the construction area as I used to be.
We might take it back even longer, not 30 or 300, but way back in the early middle ages.
There was no shortage of timber at that time, but space was. The lots in the early cities were about 30 feet max and the the typical set up was inherited from farmer houses, a bunch of poles dug in the ground in four or five rows.
Having only reed as roofing material (lots of it) the pitch of the roofes needed to be a minimum of 45 degrees and usually 4:3, which was easier for the carpenter (3-4-5)

These houses were all heated by a fire in the middle. The smoke took care of preserving the construction and was let out by some holes in the roof. It was also used to preserve meat and fish.
But space even got more sparse in the cities and they skipped the two lower rows, moved the fireplace to the side and built channels for it.
Now, the attics could be used for storage and sleeping.

As I see it, the roofs in your parts are there for the trusses only…

I am not advocating to introduce the traditional timberframe back, but we have have built some with laminated wood (bigger dimensioned wood is also sparse) and prefabricated sandwich roofs (ply, sls and isolation)
Very simple to make/adjust at site or in the shop and only raw materials needed.

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Trusses serve several purposes here Mike (store junk):

  1. Speed of installation being the main reason as labour cost is super high, (more so with a skilled trade shortage)
  2. A lot of designs are open plan here, and a truss will span unsupported
  3. Most carpenters these days do not know how to cut a roof onsite
    4We rarely have vaulted ceilings or raked ceilings here, I think it’s mainly due to the cost associated with heating and cooling unused space. It gets bloody hot in most of Australia and in many parts it gets below freezing for 3 months of the year.
    Trusses are good for running service: EG Airconditioning, special lighting, ducted vac water pipes etc ( not that you can’t do that with a pitched roof I suppose)

My personal choice is a pitched roof, but I am getting old.

A pitched roof is usually the premium option, and most do not care about things they can’t see… .except when the cornices (crown molding) start cracking.

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Well, the average footprint of Australia (and America) exceeds most of us regarding energy, I suppose. We builders tend to ‘give what the client wants’. There is a role for the designer, I believe to move towards a more sustainable approach.
(I live in an old house single glazed windows, with energy label H, one of the lowest. I tend to joke that I actually do have double glazing, but live in the middle of it :slight_smile:

Yes, there is the advantage of the open plan, but taking in to account the human aspect, how large can a room get before it starts to feel uncomfortable? Maybe it’s just a luxery problem. When the time comes to get rid of supporting internal walls, there is usually a way to divert the loads by placing a steel beam or something. Anyway, don’t underestimate the power of laminated sandwich panels:
image
With less supporting girders needed.

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Great video Andrew… very well described and easy to follow :smiley:

I can imagine the chippy’s face when I tell him…your job this week is to cut 450 birdsmouths in the rafters :smiley:

I’m in favour of pitched roofs…valted/skillion ceiilings are pretty hard to beat. But how about making the whole roof offsite then heli-lifting it into place? :stuck_out_tongue:

Not too familiar with Aussie but here in NZ the only thing that saved a lot of those old houses from falling down was the quality of that original timber…it didnt rot, was stable and very tough. We also kept to single-storey, pitched roofs and the building sites were basically flat. I just don’t think I’d put too much faith in Pinus Radiata for main bearers.

Andrew for pitched roofs is it typical to add steel straps or ply roof underlay for additional bracing? Or do purlins take care of that?

Cheers!

do have double glazing, but live in the middle of it.

Funny I’ve not heard that before. :grin:
Yes I agree we do build homes bigger than what we need, I guess it is because we have so much land vs population, and our kids never move out.

We builders tend to ‘give what the client wants’

Yep, the client has the final say or the builder finds another job in most places around the world.
I design and build and rarely build anyone else’s plans so for me it is about doing my best to educate the client but as you say clients always have the final say and rightly so as they pay.

how large can a room get before it starts to feel uncomfortable.

My answer is when it Ecos, as then it becomes unbearable. I made this mistake in my combined kitchen lounge living space, ill never do it again, too many hard surfaces & not enough soft furnishings. I didn’t trust though I used continuous span engineered timber rafters and purlins.

he power of laminated sandwich panels.

I created a dynamic component for sandwich panel years ago but I never actually used them on a project, in saying this I am contemplating removing a trussed roof from a house in QLD Australia as its blocking all of the natural light, it looks bad and I want to add roof windows to lower the energy consumption in winter at the same time as providing natural sunlight.
I am thinking about using sandwich panels for part of the project.

Hey Sam, In Australia the overwhelming majority of rooves are using steel straps for bracing. In my time I have only seen 1 or 2 roofs or walls fully sheeted as they do in the States. In saying that the one or two rooves that were sheeted before external lining were passive homes which is becoming a thing here. I assume sheeting walls and roof is more predominant Stateside is because of earthquakes and shingles not requiring battens?
In Australia, we generally use sheet metal roofs or tile roofs with battens. The Sheet roofs will brace contribute to bracing, however, the battens would do minimal for bracing I’d expect.

Like your brief tour of early timber framed houses Jack, but…

Here in the UK, I believe oak (the primary timber for building houses with) was being eaten up at a furious rate for boatbuilding. Also, it must have been relatively expensive as the better houses often had much more timber than was strictly necessary - a question of proving that “I am so much richer than yow” as one comedian put it. Easy to think that it was the only timber used or that the medieval houses survive because they were so well built/designed, conveniently ignoring the possibility that those that were poorly designed/built, used inferior materials, or were built in unsuitable locations, simply haven’t survived.

I have often wondered why roofs that were once thatched tend to have a pitch of about 50 degrees, even long after thatch started to be replaced with terracotta tiles. Your explanation makes a lot of sense.

You must have lost a lot of boats then :slight_smile:
I don’t want to rattle up our disagreements in the past, but we also lost some boats, ofcourse. We replaced Oak by pine and fir/spruce for the beams etc. Imported from Eastern Europe and Scandinavia.
You also had more stone available, I believe. And a more stable undergound.

But that might not be the main reason for the preservation, often, the front and windows where completely renovated along the current fashion of that time and changing usage (shop/pub/resident/bed&breakfast)
Its dimensions and how it was built made it easy to adapt for the residents of the time. It is precisely this flexibility and the human scale of these houses that make them so attractive to live in.

maybe running off topic, here

We used to you old-growth hardwoord… That changed pretty quickly.

So I am going to renovate the home, the plan is to remove the roof and see what I can come up with to enable the winter sun to shine into the living space.
Today I modelled up the home as it stands currently from a plan I received from the estate agent.
I will create a new post guys as I think the process will help newcomers.
BTW this is my home in Queensland Australia so it’ll be a drawn-out process in between work. Here is a screenshot of the model.