Rebar shop drawing lengths

[rn14]

I have a quick one (yes I am new to the job). I am reviewing some shop drawings for rebar and the bending detail schedule had dimensions (which are probably some standard I dont know about) that I dont understand. It has lengths like "1-111" and "0-08".
Teach me sumtin!

 

[UcfSE]

Somewhere on the drawing there should be an explanation of what that means. This is also a good question for your supervisor.

 

[miecz]

We don't feel it's our responsibility to check length of rebar in the schedules. Bar size, spacing, splice length, but not length of bars.

 

[Lion06]

I usually do a "sanity check" to make sure the length of bar is at least in the right ballpark. For dowels or the like, I do typically check all of the lengths. It doesn't matter what they have called out for lap length if the length of bar that they are providing isn't sufficient.

 

[rn14]

Hmmm, I dont see anything on the drawing that explains the dimensions. I also checked the CRSI site but no info and my supervisior is out if the office for the day and besides a couple draftsmen I am the only person here.

I'm not checking the lengths per se, I'm just trying to figure out what they are doing in a particular area to be sure it is what we had in mind.

 

[JStephen]

I've run into this in the past, and managed to decipher them, but that's been a while, too. And no, there was not a key on the drawings.

Check if that first one could be 1'-11-1/8" or something of the sort- the final fraction could be eights or sixteenths or whatever, I don't recall. And the 0-08 would be 0'-8".

It's not unreasonable to call the folks up that did it and ask them what that means.

 

[rn14]

Ya, I was think I would just shhot them a quick call.

 

[PMR06]

JStephen has the idea. You can deduce what the last digit might mean. 16ths are out because it is only one digit, and if you see digits greater than 4, then it is probably 8ths.

All of the shop drawings we have ever produced have been with that nomenclature and the last number was 8ths.

 

[UcfSE]

The last number is probably the number of 1/4's of an inch. The other three are feet and inches.

 

[msquared48]

Don't assume anything - call the detailer. It's his drawing and standard. Let him explain it to you.

Mike McCann
MMC Engineering

 

[cvg]

I'm not a structural, but it seems a bit of overkill to dimension rebar to the 1/8 inch... Nearest 1/4 or even 1/2 inch would generally be sufficient IMHO

 

[nutte]

I second what Mike said. We can debate here all day what the numbers might mean, what some numbers on a job we did last week showed, whether or not the rebar should be detailed to the inch/half/quarter/eighth/sixteenth, what "standard practice" dictates it should be, and we still might not be right. This would be so easily solved with a quick phone call.

 

[JrStructuralEng]

I agree with mike, and cvg.

miecz, our office never checks rebar length either. We check the size, spacing, laps, dowels,etc. If I have time I might check a few lengths. But I can tell you what happens if you start to correct them on too many length errors, the contractor and the rebar supplier start to rely on you to do their work.

 

[cvg]

jrstructuraleng - there's an easy solution to that, just return the shop drawings "not approved" and ask them to resubmit after checking all the lengths. If they have to resubmit every time because they didn't do any QC checks on the lengths, maybe they will start doing it. Especially if this delays the contractor...

 

[miecz]

I recently learned from our field inspector that the bars are always short an inch or two, resulting in short lap splices on our water treatment tanks. I guess that's how the fabricator makes money. There's not much the inspector can do about it once the steel in in place. I'm gonna add a couple of inches to my laps from now on.

 

[JrStructuralEng]

If I notice length errors I would correct them cvg, but I definetly don't make an effort to check each bar length. I usually check one or two, our review stamp clearly indicates that we don't check length.

 

[boffintech]

miezc Check ACi-117 chapter. Your bars are probably within tolerance.

2.2.8 Embedded length of bars and length of bar laps No. 3 through 11 (No. 10 through 36) bar sizes –1 in. (25 mm)

 

[StructFton]

What I have been doing in the past year or so, is getting the Contractor to stamp the drawings as 'approved by Contractor' or 'acceptable for consultant review' when they get it from their fabricator and before they send it to us for review. This gets the Contractor in the habit of at least looking at the drawings and catching obvious errors before wasting our time with what would be a 'rejected' submission. This helps eliminate errors, and keeps the Consultants from looking like the bad guys for rejecting submisisons.