welding C pearling splice

[the human torch]

What type of weld is best to splice together to sections of c pearling?
Instead of a Butt Joint, what can I do?

[Burnit]

What is c pearling

[duaneb55]

I think tht is referring to what may also be called a 'stringer' or the C shaped structural piece that runs between vertical posts and rafters of a steel building.

If so I would think a fish-plate butt joint as it doesn't seem a lap joint would join up properly due to the like shape of both pieces. ??

[denrep]

Originally Posted by Burnit

What is c pearling

Probably "C purlins" the light gauge secondary framing in an engineered steel building.

But we need details from...The human torch



Edit: Ouch! I bumped heads with Duaneb55

[duaneb55]

Originally Posted by denrep

Probably "C purlins" the light gauge secondary framing in an engineered steel building.

But we need details from...The human torch



Edit: Ouch! I bumped heads with Duaneb55

Good ole industrial grade solid granite here!

[DDA52]

It will depend on where on the run it is, but they should be plated. Purlin splices should always be on a structural member anyway. When it is on a beam, we just use the purlin clip as the plate and weld around it 100%. It has always passed that way.

[Oldtimer]

It can be butt welded just like pipe or plate and is just as strong as the rest of the section like any weld should be. That said, it takes more time than the plate and is a pain to do usually because the ends are usually tweaked a little where the come out of the die. Landing the joint on a cross member is ideal. Don't know what the codes are in any other state than mine. Use the codes for your area.

After all that I've never built a building that had to meet a code. In fact my state is weird in that they have no standards for metal buildings. All you have to have is a civil engineer or a registered architech (spelling) seal stamped on the prints and the state will issue the building permit. They do have to meet a higher wind rating than over in Texas. I didn't realise that the state line would slow down the wind until I dealt with the state building authority.

The only time I've ever uses the buttweld on C purlin is on things for myself and a brother- in law and it was a case of we had more time than money and none of the welds have ever bent or broke. They didn't get inspected either.

[DDA52]

Oldtimer, you say you don't know the codes and then tell him it is ok to break one of the most holy rules. Which is it? No structural purlin manufacturer would ever approve a butt weld without any type of plating...ever. Depending on loading, span, etc, they will require a minimum two foot each direction overlap of some sort...either plate or bypass. The liability factor is just too great for a butt without reinforcement. It just is not done. That doesn't mean it could not be done, it just isn't.

And just how would you know the wind load ratings here? I seem to recall about 6 or 7 different area specific ratings ranging from 70mph to 150 mph on the coast and a few mountain passes. Unless you are on the coast, I doubt you are building to withstand a Cat 3 hurricane.

[Bob]

I use a weld clip for a plate and weld the top and bottom and then weld the purlane completely. I dont like splicing in the roof but have done it on my own building and friends, never on a customers building. It would seem to show poor planning on my part.

[DDA52]

But if the span is over 30' you have to splice on the beams. That is SOP. Same with welding them to the clips. Sure beats a butt weld.

[duaneb55]

[QUOTE=DDA52;211843]I seem to recall about 6 or 7 different area specific ratings ranging from 70mph to 150 mph on the coast...QUOTE]

Funny you should mention that DDA52. A few years back the company I work for got a smokin' deal on a 50' x 50' (I think those dims are correct) because the building site got relocated from the one side of IH10 to the other in Houston and the building that had already been purchased and met the original wind load ratings didn't meet the new ones on the other side!

[DDA52]

Funny how that works, isn't it? Wouldn't be much of an issue, though. All one has to do is get the original engineer to give you a plan to augment it. The usual difference is purlin and wall girt spacing. Screw spacing on the sheets as well. Very, very rarely is it anything with the beamage or even base plate bolts. It does happen, though. Sometimes they increase the bracing. All of it is simple cut and weld or drill and bolt stuff. Piece of cake.

[duaneb55]

Sure sounds simple enough. Do you think maybe the building folks just took advantage of the opportunity to sell another unit? Not that THAT would ever happen.

[Oldtimer]

DDA52, You need to brush up on your reading skills. I never told him to break the rules.I stated specifically I didn't know the codes for any other state and to use the codes for his area.The crack about the state line slowing down the wind was a joke. I also stated that I had never used the butt weld except for myself and a brother- in- law.

[mooseye]

I can't say for sure about "C" purlins but I have had "Z" purlins come in from the manufacture that were butt welded with no reinforcement. I couldn't believe it with my own eyes, but it is as someone said, It should have all the strength of the base metal and some if correctly applied.

Originally Posted by DDA52

Oldtimer, you say you don't know the codes and then tell him it is ok to break one of the most holy rules. Which is it? No structural purlin manufacturer would ever approve a butt weld without any type of plating...ever. Depending on loading, span, etc, they will require a minimum two foot each direction overlap of some sort...either plate or bypass. The liability factor is just too great for a butt without reinforcement. It just is not done. That doesn't mean it could not be done, it just isn't.

And just how would you know the wind load ratings here? I seem to recall about 6 or 7 different area specific ratings ranging from 70mph to 150 mph on the coast and a few mountain passes. Unless you are on the coast, I doubt you are building to withstand a Cat 3 hurricane.

[DDA52]

Originally Posted by Oldtimer

DDA52, You need to brush up on your reading skills. I never told him to break the rules.I stated specifically I didn't know the codes for any other state and to use the codes for his area.The crack about the state line slowing down the wind was a joke. I also stated that I had never used the butt weld except for myself and a brother- in- law.

My reading comprehension is fine. You said it is fine and just as strong...the manufacturers disagree. But what do I know about it? I've only been dealing with this specific crap for nearly 25 years.


Mooseye, if it came from the plant that way, it should be kosher. At least any liability is on the plant. Field butt welding without reinforcement is what I was referring to. In reality, there is no reason to butt weld a Z purlin. They can be overlapped and welded like that without any troubles for the most part.

[Oldtimer]

Obviously it isn't since you are still ignoring what I said just to rag on me because I stated a buttweld on c-purlin is just as strong as a buttweld in other mild steel material. Nowhere did I tell him to ignore codes. If you have developed enough skill in those 25 years to make a decent buttweld you can prove it to yourself. Weld one up and try to destroy it. If it fails in the weld you need to practice a little more on your skills. If you want to brag about years being a welder I have a few on you and they were spent welding up things that had a hell of a lot more stress on them than a piece of c-purlin does. I'm done with this.

[DDA52]

Oldtimer, I am not ragging on you nor attacking you like you are attacking me. Question my skills and intelligence all you want...you will loose. No one was bragging either. I have been dealing with shaped sheetmetal components for that long. I know what the manufacturers will and will not warrant. Butt welds in the field will be rejected 100% of the time without the proper backup.

I said nothing of code.....I said the manufacturers do not recommend it. I am well aware that they can be welded and it will hold. I to have welded heavier stuff and have the papers to prove it somewhere. That is not what was the issue. Nor was whether or not you have been doing this longer than me or vice versa...it was the statement that it is fine to butt weld it when the sanctioning entities say it is not. Codes be damned...they are irrelavent if the manufacturer says do not do it without doing X, Y and Z. That is the only way one can sell work is by doing it as it should be done and thereby protecting ones self from liability and protecting the purchaser's warranty on the materials. There is a lot more to this business than whether it will or will not work.

Stop being so sensitive.