Losing Money on Cabling Jobs? Find the 5 Profit Leaks

You won the bid. The customer signed. Your crew showed up, pulled the cable, terminated everything, tested clean, and got paid. And somehow, when you look at the bank account three months later, there's less in it than there should be. If that sounds familiar, you're not alone — and the problem almost never lives where you think it does.

Most contractors who lose money on jobs they won go looking for one big mistake. A bad estimate, a lazy tech, a customer who stiffed them. But that's rarely how it works. Estimating errors alone cost U.S. construction companies somewhere north of $270 billion a year, and the bulk of that isn't dramatic blowups — it's slow leaks. A half day of idle crew here, ten free drops there, a burden rate you never actually calculated. The money leaks out in dribbles, and because nobody's measuring during the job, you only find out at closeout. Or worse, at tax time.

Let's walk through where it actually goes.

Your labor number was fiction before the job started

Labor is 60 to 70% of the cost on a typical structured cabling job. So if your labor number is wrong, nothing else you do matters much. And here's the uncomfortable part: most shops bidding off "what I pay my guys" have a labor number that's wrong by 40% or more.

Say you pay a tech $28 an hour. That's not what he costs you. Add employer payroll taxes, workers' comp, liability insurance, health benefits if you offer them, paid time off, the truck he drives, the tester he carries, and the training you send him to. For low-voltage and electrical work, burden typically runs 38 to 55% on top of base wages — most shops land between 42 and 52%. At a 45% burden, your $28/hr tech actually costs you about $40.60 an hour before you've recovered a dime of office overhead or made a nickel of profit.

Now run the math on a 100-drop job you estimated at 2.5 hours per drop. That's 250 labor hours. If you bid them at $28 plus a little cushion instead of the true $40-plus, you built a $3,000 hole into the job before anyone loaded a van. You didn't lose that money on the job — you gave it away in the proposal.

There's a cousin to this mistake that's just as expensive: confusing markup with margin. If you want a 30% gross margin and you mark your costs up 30%, you're not getting 30% — you're getting about 23%. A 30% margin requires a 43% markup. That seven-point gap doesn't sound like much until you realize it's often the entire profit on the job. Plenty of contractors have run "profitable" for years on paper while this one arithmetic error quietly ate everything above breakeven.

The free work you're doing without noticing

Here's a scene every cabling contractor knows. You're two weeks into a 200-drop office build-out. The IT manager walks up and says, "Hey, while you're up there, can you add four drops in the conference room? And the owner wants two APs in the lobby now." Your lead tech says sure, no problem — it's twenty minutes of pulling and you've got slack cable on the spool anyway.

Except it's never twenty minutes. It's the pathway, the terminations, the faceplates, the patch panel positions, the labeling, the testing, the as-built updates. Call it three to four hours all-in, times your true burdened rate, plus materials. That one friendly "sure" cost you $200 to $300. Do it a dozen times over a project — and on a busy commercial job, you will — and you've handed back $2,500 to $4,000 of margin without ever writing it down.

Industry job-costing studies keep finding the same pattern: by the end of a project, contractors have quietly performed 10 to 15% more work than the contract described and absorbed every dollar of it. On a $60,000 cabling package, that's potentially $6,000 to $9,000 of unbilled scope. That's not a rounding error. That's the difference between a good year and wondering why you're working weekends for nothing.

The fix isn't complicated, but it requires discipline your field crew probably doesn't have yet because nobody gave them the authority or the script. Every added drop, every relocated outlet, every "while you're up there" gets a written change order — even a one-line email from your phone — priced and acknowledged before the work happens. Small T&M change orders on cabling work commonly run $150 to $250 per added drop, which not coincidentally is right around what a straightforward commercial Cat6 drop should sell for in the first place. If the GC or the client balks at paperwork for small stuff, agree on a unit price up front in the contract: "additional drops beyond contracted count: $185 each." Now your lead tech can say yes on the spot and it still hits the invoice.

And this is the practical mistake to avoid, learned the hard way by more contractors than will admit it: never let the verbal yes happen on site without a paper trail, because you will not remember to bill it, and if you do remember, the client won't remember agreeing. Sixty days later it's your word against a project manager who's already blown his budget. You'll eat it to keep the relationship. Every time.

Job costing while the job is running, not after

The third leak isn't a single cost — it's blindness. Most small shops find out whether a job made money when the accountant closes it out, weeks or months after the crew demobilized. By then, every lesson is expensive history.

The contractors who consistently hit their margins do something boring instead: they compare actual hours and materials to the estimate every single week the job runs. Not with fancy software necessarily — a spreadsheet works fine at first. Estimated hours per phase versus burned hours per phase. If you bid the rough-in at 120 hours and you've burned 80 hours at 50% complete, you're trending 33% over and you still have time to do something about it. Maybe the ceiling turned out to be hard-lid instead of the T-bar you assumed. Maybe the GC's framing schedule has your crew mobilizing three times instead of once. Maybe one tech is averaging four drops a day while the industry norm on open-ceiling commercial work is closer to eight to ten.

Every one of those problems has a remedy — a change order for differing site conditions, a delay claim, a coaching conversation — but only if you catch it mid-job. Catch it at closeout and all you've got is a story.

While you're at it, track change-order work under its own cost code, separate from base contract hours. If you lump it all together, you can't tell whether your change orders are profitable or whether you're just doing extra work at a discount. A lot of contractors discover their change orders — the work that's supposed to carry premium pricing — are actually their worst-margin hours because they're done piecemeal, out of sequence, with extra mobilization nobody priced.

One more place to look: job size and site conditions. Per-drop economics swing hard with scale. A 10-drop service call might genuinely cost you $350 to $400 a drop once mobilization and setup are spread across so few units, while a 500-drop new-construction pull on the same building might pencil at $175. If you're bidding small jobs at big-job unit prices because "that's what drops go for," you're losing money on every small job you win — and small jobs are probably most of what you win. Same story with plenum spaces, which push cable cost up 30 to 50%, and finished-ceiling retrofits, which can double your labor per drop compared to open construction. Flat per-drop pricing across all conditions means your easy jobs subsidize your hard ones, and the hard ones are the ones you'll win most often, because your flat price looks cheap exactly when the work is expensive.

Add it up and the pattern is clear: you're not losing money because you're bad at pulling cable. You're losing it because the business math — burden, margin, change control, weekly costing — never got the same attention as the craft. Pick one leak and plug it this month. Start with your burdened labor rate, because every other number downstream depends on it. Then make written change orders a reflex instead of an exception. Do those two things and most contractors find three to five points of margin they didn't know they'd been giving away — on the jobs they were already winning.