Field Welding verses Field Bolting to Existing Steel

[PEFLWI]

What do you think is better and more economical, field welding or field bolting new steel beams to existing steel beams/girders? I need to connect new W8 beams to existing W12, W14, or W16 girders.

Thanks!

 

[human909]

Normally field bolting but it is a case by case bases for me and I do lots of work on existing sites. Any old contractor can grab a magdrill and put a few holes in a beam. Takes a fair bit more skilled work for a weld. But like I said it is case by case.

 

[EdStainless]

If there are a lot of joints (making it worth the time to bring a welder to site), and the old steel is weldable, and the fit up will be fairly easy, and the surface prep won't be too hard, then weld.
In many cases bolting is the preferred option.

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P.E. Metallurgy, consulting work welcomed

 

[GC_Hopi]

Then you have to consider hot work permits for welding. As stated bolting is generally option 1 but sometimes there is no substitute for welding especially when you have difficult "field conditions". And under "field conditions" I would put a GC who is not detail oriented so nothing is field verified as requested on the drawings or they start averaging measurements. SMH

 

[Enable]

Huh. I guess I'm odd one out on this one.

I do restoration a fair bit and my view is the exact opposite of my colleagues here. I vastly prefer welding in these circumstances. Trying to get things lined up to 1/16" while drilling in the air is a hard go at least by comparison to clamp and fillet.

Of course it does depend on location and other factors (such as steel weldability, necessary precautions for hot work, yadda, yadda). But if I had a choice and no restrictions, usually welding.

 

[271828]

I'm another odd one.

In every such case I can remember in my entire career, field welding was used.

 

[1503-44]

If its a shop job with short spans and low rise columns, bolting can make sense for transport convenience. On the other hand, bolting huge, heavy, long spans, or offshore structures, where convenience of transport is not to be had under any circumstance, then not so great.

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[XR250]

I just had a guy dill and install 4 bolts in a column to beam connection for me. He did not even bother with his mag drill as the access was a bit tight. Some sharp bits and then finished with a reamer. Took him less than 30 minutes.

 

[AskTooMuch]

If inside a plant, field welding is usually more expensive.

 

[CANPRO]

The answer to this question is very much case specific. However, the answer to bolt or weld is a 2 part question. Ultimately you should be aiming to bolt the new beam to the new connection material, because this is the stage of erection that is safety critical and most costly (crane and/or rentals) - you want this stage to go quickly, i.e. bolting at this stage. The question is now how do you connect the new connection material to the existing beam. This will come down to practical restrictions like fire, drill/weld access, and also erector preference. Barring no other restrictions I'd typically weld the new connection material and bolt the new beam.

 

[Veer007]

For the new beam to new girder beam connection, In our detailers field, we always prefer shop welding/bolting and field bolting that's what our fabricator/erector also likes and easy installation.

In ex. conditions that can be completely opposite, such as bolting in the workshop with SSL holes (for adjustment if needed) and welding on-site to the ex. member, We always think it's an expensive job to drill holes in the field, right?

I was just wondering if drilling holes in an existing beam doesn't make the beam weak?

Thanks in advance!!