A build thread

[DaveTTC]

Love the sound of it. Likendoing stiff outside the box

Dave TTC
Turning Wood Into Art

[meadow street]

this is how I interpret the customers structural steel requirements to date.

the drawing here is my drawing, based on sketches from the customer, which lacked sufficient knee support, and had a funny arrangement under the windows.........there was one, and only one, vertical web in the truss on the drawings presented to me ( a king post I suppose ) which sort of scared me

i guess I come to this job with a shed type mentality.

the other thing that threw me initially was that this is the side of the building.......usually I would expect this to be on the end of a building.

shall post up the " end view" shortly.

totally open to suggestions, but the huge glass panels are sort of an essential component.

im concerned about the cantilever, since I'm used to seeing a column in a portal frame go into the ground. then there is a cantilever past the already 900 mm from the pier centres.....talk about a hangover?

the glass is high performance, just in case you are wondering about west elevation and all that glass.

that's the latest

[meadow street]

this is how I interpret the other elevation.

bays essentially.

minus the wall purlins or battens.

the building is approx 900mm to the top of the Ub beam.

bays are at approx 2800 centres ( sorry)

columns are are only about 2600 according to customer.

total building height sits at around 4 m.

[meadow street]

Spray Primed the bearers today, but it was quite a job, since the "duty cycle" of a small generator which was on site today was pity full! Less than a minute and the compressor was stalling.........switch off.....spray a little .....turn compressor on....stall.......

Better than hand brushing though as the coverage was good and even in the no-wind conditions.

Left the column plate bearing points un painted.

Another beautiful high pressure (1030 hPa ) day.

[DaveTTC]

Looking good

Dave TTC
Turning Wood Into Art

[WelderMick]

the "duty cycle" of a small generator which was on site today was pity full!

Nothing more frustrating than waiting for a machine !! This is why machines won't take over the world... imagine terminator with a low duty cycle.

I'm looking forward to your progress on this one Meadow. What did you do about the flash rust? Let us know what you used for converter/paint.

Cheers

- Mick

[meadow street]

G'day Mick,

flash rust by its name is quick acting surface corrosion as you know.

i I found that by power brushing ( wire wheel and cup brushes) and drill brushing with a rotary tip, removed it very well, leaving no scaly rust on the steel.

Then went ahead and blew the powdery swarth off with the compressor and started priming with Metalshield, I think it was called. Oil based primer for steel, tin warmed up in the sun, thinned for spraying and applied. about 80 $ per 4 L

i think it's going to be ok

Couldnt find a cheap cheap enamel top coat anywhere yet......in a tintable one anyhow. Plenty of cheap white on the market. Looks like I'll be paying another $80 for the top coat : (

btw how do you reckon a 100x50 x2mm rhs would compare to a c150 or z150 purlin (1.5mm)?

spann 2.8mm. I'm not up with the ins and outs unfortunately.

[WelderMick]

I probably would've done the same - (wire brush rather than a converter) - I was curious, because I know some guys actually encourage the flash rust with the theory that a converter will bond better. I've also thought about marine epoxy paints - but expensive and harder to apply.

I'm not sure what you're asking about purlins vs RHS (and I'm not qualified to answer anyway). Are you talking about joists between your bearers? If the RHS is long side vertical then it would be more stable than the C or Z purlin also vertical. One thing I would consider with C purlins particularly is whether they could rust. Under the house there is no rain to wash away salt spray. I know the site isn't next to the coast, but where I live it is the first consideration - just food for thought.

Cheers

- Mick

[meadow street]

specifically to use RHS as a roof purlin in a two bay situation span 2.8m instead of common 150 c/z sections.

im hoping 100x50x2mm RHS will be as strong of stronger than a c15015 or z15015 purlin.

ive got lots of 100x50 x2 at my disposal and the customer also wants some canilevers which will look better in rhs in my opinion. have seen a few buildings with purlin cantilevers at the gable and they look lightweight and cheap : )

ive rung a few engineer's offices but they never seem to get back to me

i looked into rust converter and even rang a mob about bulk........needed it done quick so laid back on the brush and prime approach. if I had time I would order 3 -5 percent phosphoric acid and play with that. most of the rust coverters I looked at (essentially phospho acid) were about $20 /L .......eek

below is a curved roof building with c section roof purlins and a cantilever

[DaveTTC]

I prefer rhs but lack the expertise to say how it compares for strength. My gut says it would do what you want

Dave TTC
Turning Wood Into Art

[WelderMick]

specifically to use RHS as a roof purlin in a two bay situation span 2.8m instead of common 150 c/z sections.

Gotcha... I had my mind floor joists.
Personally I'd go for the RHS, particularly if you're going to see it (think protruding screws, etc.) and I'd find some end caps to suit.
- Mick

[RustyArc]

A *very* quick check suggests the 100x50 RHS would exhibit almost twice the deflection compared to a 150mm C section, but I'd be talking to an engineer - issues such as torsional stiffness might make the RHS a better option, or the strength of the RHS may be sufficient for the application, or you might stack the RHS in some places to get the required strength/stiffness.

[meadow street]

A *very* quick check suggests the 100x50 RHS would exhibit almost twice the deflection compared to a 150mm C section, but I'd be talking to an engineer - issues such as torsional stiffness might make the RHS a better option, or the strength of the RHS may be sufficient for the application, or you might stack the RHS in some places to get the required strength/stiffness.

good thinking Rusty ....thanks

[meadow street]

got the bearers in and cleaned up the site today. feeling good.

hopefully spray a top coat on tomorrow and go from there with welding the columns and trusses to suit the customers preferences.

[Michael G]

Beautiful setting and nice work, but every time I see those beams I do keep asking myself "How big is the granny?"
If the rest of the structure is in keeping with what has been done so far it's going to be waaaay solid.

Michael