Average Length of Cat5 Run

Bob Simon wrote in news: snipped-for-privacy@4ax.com:

6 feet between each outlet is a good idea, but it really depends on out the machines are layed out on the floor.

You can always order more cabling than you need and return the excess to the vendor.

It looks like your minimum run (for the estimate purposes, your real min could be 30' or even less) is about 140', your max is 220' (ups and downs, slacks included). So, your estimate average is 180?. That's, BTW, is close to the statistical average of 175' we go by when no length data is available. That yields 5 full runs per box of 1000'. So, your estimated number of boxes should have been (125+125)/5=50 boxes. Now, if your installers really watch the waste, they can easily get this number down to

45 by using shorties where appropriate. Therefore don't order 50, just get 30 to start with and then see how they burn through the boxes before you order the remaining 15-20. It may also make sense to first order one pallet, which would be somewhere between 30 and 36, depending on the type of cable and the manufacturer?s standard pallet size.

Good luck!

Back in the days, when I was buying lots of cable (one job was 160 Km @ 300 metres per roll), I'd guesstimate the total and add 10%. Then do the long runs first. I used to count the floor or ceiling tiles to make my estimate, if a floor plan wasn't available. Excess cable can always be used elsewhere.

If this is going to be his business, he'll be needing it again, sooner or later.

Congrats on your first job...

I would do what Dmitri said. Buy like 30 boxes and start from there. You can always buy more down the road if needed.

Also, you can lower your cable box count by finding the shortest path to your closet, though sometimes you cant always go the shortest route.

Perkowski

One trick I learned about 10 years ago was to take the square footage and divide by the number of drop locations. In this case, 20,000 square feet divided by 125 yields an average length of 160 feet. Multiply that by 250 - the number of cables - and you come up with

40,000 feet or 40 boxes. If you really want to be certain you have enough cable, then take the average length of 160 feet and add 24 feet for up/down/slack and then you are right back to the 175 - 180 Dmitri uses.

Rodgers Platt

Well done dude!! Wish you all luck and a thousand more contracts!!

Usually i add 6m per run when working out quotations, but take 20%-30% more material when going to a site.

The highest cost is man hours....and since most cables are drawn 'together' it's hardly ever a question of "how many can i maximise the number of runs given the least number of boxes" maths problem :-)

Excess cable (half full boxes, boxes with just 50m left, etc) are stashed away for the next installation. I try to always write down the remaining length of cable very visibly on each box. This helps picking out the best four boxes for a 30m run.

Brendon

++++

One guy I used to work with, ordered a 600 metre roll of 6 pair cable for each of a couple of dozen jobs. Problem was, each job needed less than 10 M of this type cable. He had a lot of extra cable.

Interesting rule-of-thumb, but I suspect it fails for very sparse or very dense coverage. Try 20,000 sft with 10 outlets or a tight cubecity with 1000.

-- Robert

Thanks! That's a good trick. Bob

-- Bob Simon remove x from domain for private replies

Thank you.

I see what you mean.

I like your idea but I'm not sure how you tell how much is left in the box.

-- Bob Simon remove x from domain for private replies

You can get counters, that measure how much cable you pull. Just make note of that, add a bit of fudge factor and write it on the box.

You can also get a rough estimate, by weighing the box.

Weigh'em! You can also use the feet markers printed on the jackets (write on box when opening if it's not printed on). It's important to track if you don't want to wind up with a bunch of short ends.

Best is big 5000' spools if you can handle them. Otherwise, pull longer runs first off fresh boxes then the shorter ones from the "not enough left" boxes.

If you track some pulls, you'll have a good idea of what the next one will take.

-- Robert

'Most' cable will have the length written on the cable itself :-)

Btw...I misunderstood the original posting and thought you were referring to how many boxes you need to buy given a known number of runs

• respective lengths. In my case most jobs were always quoted for after a site visit, armed with both floor plans and a clear identification of where points are to be terminated, etc. Jobs usually involved trunking, drilling thorugh concrete walls :-( and installation of computers and stuff.

B.

This job was quoted on a per pull basis rather than a total job.

-- Bob Simon remove x from domain for private replies

To go along with the other trick which some people manage to point out has its limitations at the extreme situations, have your installers write down the starting footage count on the box. At the end of the day, subtract the count form the current marker and the starting number and you have the amount left in the box. And that is PRETTY DARN ACCURATE IN ALL INSTANCES!

Rodgers Platt

Just curious, what state and how much per pull ? are you counting 1 phone, 1 data as 2 pulls or 1 also are you certifying the lines ?

SonnyD

Most cable has footage markers printed on the jacket. Better brands all start at 1000 and count down to 0, so you always, easily, know how much is left. If it doesn't count-down to 0, mark the starting footage count on the box, and do the math to figure out how much is left.

I'm in Louisiana and I quoted $75 per pull. 1 Voice + 1 Data = 2 pulls. I know it's a low rate but I REALLY wanted the job.

Certification is not mandatory and I didn't state that we'd do it. But my boss tells me the wiring guys have a tester that will store the results so I guess I might as well give the file to the customer at the end of the job.

Bob

-- Bob Simon remove x from domain for private replies