Steel framed extension

[thinfourth]

We are considering an extension on our house and the first architect came round had a look at our initial plans and stated "Oh you'll need a big steel frame for that"

Now if have the space, equipment and skills to build this myself.

Is there any reason why i can't?

 

[KemppiFrog]

I am all ears on this one. I built a few steel frame buildings, but not in UK. Be interesting to hear if planning requires any stress analysis.

 

[mike os]

planning dont care about the how...
building control ( council or independent ) will want full calculations for all elements, joints etc
also structural welds will need doing by a certified welder

 

[Engineer1964]

If you do structural steel work for a living then you should sail through getting the steelwork done, it could save you a few grand, How ever ideally the welder who is doing the job should be coded and have a big enough welder to do structural welds.

However if your just a hobby welder with a 100amp buzzbox then forget it

 

[thinfourth]

I've got a 180 amp MIG which should be fine

The only thing i don't have is being a coded welder

 

[zzr1200]

I've got a 180 amp MIG which should be fine

The only thing i don't have is being a coded welder

If your welding RSJ's likely to be a buildings frame I'd expect a mig welder of at least 250/300 amp min that will go into spray transfer, or an 180amp min oil cooled stick welder would be ok.

I wouldn't touch it with a 180amp mig.

IOM.

 

[Welderpaul]

Easy if you have the machines, know how, and can handle big sections of steel.

If not, not so easy. A 180amp Mig won't do the job, we do a lot of structural steelwork and, as an indication, our sets are 400-500 amp.

You will need a structural engineer to look at the design, prepare structural calculations which will determine section size and connection details. This information needs to go to BC to enable them to review the design and check/sign the job off on site. Depending on the complexity you may need a draughtsman to detail up and provide you with fabrication details. Then you need to make it - receive and handle beams/columns, cut to length, fabricate connection plates, weld, clean the steelwork and paint.
All depends on the size of the job of course, but not always as easy as it appears from the outset.

 

[madkayaker]

Lets not forget the amount of space required for such a task as well. Paul has a shop that makes the rest of us very green with envoy and normally you can't see the floor for steel! The welder I have is a 300amp miller that was given to me by Paul as " to small" and that's before we start looking at saw needed to cut beams accurately and cleanly, metal worker to punch holes in connector plates etc etc.

 

[Engineer1964]

Exactly not to mention a mag drill I don't know how i would ever manage to drill 22mm holes in a 12 metre lenght of RSJ without one.

180am welder just isn't up to the job, as Paul says a welder with at least 400 to 500amp is neeaded, I use a Miller BluePak 450 at work and that does some lovely welds, nice and hot!!

Some local authorities insist also on NDT (Not Descructive Testing) which means you'll have to get someone who's qualified to test the welds either in the workshop or on site,

Thats why you need a large ideally 3 phase welder in the amp range, already explained to get the high amps and penetration, you won't get adequate penetration with a 180 amp welder, i'm afraid

 

[KemppiFrog]

Do you need to use RSJs? Clearly if so, then hefty kit is required. I built mostly single story in steel frame using hollow sections, within the possibilities of a 180 amp machine. Couple of two story ones with same sections, but more space frames than simple beam and post.
Perhaps the OP can give a bit more detail? Single or two story, and is it normal in the UK for the arquitect to talk about steel structures in domestic building?Esp. as this is an extension. The odd RSJ for removing a wall, but?
And he could rent a stick welder of suitable grunt for the thicker stuff.

 

[Welderpaul]

Unusual for steel to be used in domestic houses unless there is some sort of a feature - internal balcony, or a big cantilever somewhere. Do a bit for builders where they are carrying out alterations; removing walls etc.

Sounds slightly odd for an Architect to specify steelwork. they normally stick with what they know..traditional brick and block walls, timber joists etc etc etc.

 

[Hitch]

I have to disagree with a 400-500 amp welder being a must, but probably a bit more than a 180a machine to be honest....

If its a domestic job, chances are is only going to be 152s, 203s, 254s, thats about it.

When someone says a big steel frame,do they mean a big steel frame, or a couple of bits of 100mm box, with a 152x89 sat on top... like most do.

 

[dannyp]

steel frame domestic is unusual


you'll want a big mig with a watercooler do load of steel buildings at work and if for some reason i have to use an aircooled torch i get very ****** off with it after a few hours keep on haveing to wiat for it to cool down or blow it with an airline

 

[snowcat]

With the skill set, you could easily nail everything with a smallish (150 amp inverter) although stick would be much slower exactly the same standard if not better than something nailed with a MIG, both that and a MAG drill could be hired, all possible but you will need to have a good idea on what you were doing, with that said I nailed my first 40' clear span building at 17 years old with an oxford welder, a set of bottles and a pistol drill.

 

[KemppiFrog]

With the skill set, you could easily nail everything with a smallish (150 amp inverter) although stick would be much slower exactly the same standard if not better than something nailed with a MIG, both that and a MAG drill could be hired, all possible but you will need to have a good idea on what you were doing, with that said I nailed my first 40' clear span building at 17 years old with an oxford welder, a set of bottles and a pistol drill.

May be a slightly delicate question, but, When was that?

I remember my first Oxford oil cooled. No idea how good it was compared to a modern buzz-box. Learning curve.

 

[snowcat]

May be a slightly delicate question, but, When was that?

I remember my first Oxford oil cooled. No idea how good it was compared to a modern buzz-box. Learning curve.

Over 20 years ago, I still have it but cant remember the last time I used it, would have no doubt it would still work tho, also had a 400 amp quasi arc from the ship building era would run two welding sets at 100% duty cycle....

Fincord Ms mmmh them were the days.