What breaks when a plumbing business hits 3 vans

Most Adelaide plumbing businesses stall somewhere around the third van. Not because the work dries up, and not because the owner stopped trying. The business hits a set of limits that were invisible at 1 or 2 vans and become the whole job at 3.

The pattern is consistent enough to be useful. Dispatch stops working. Pricing that was fine on your own hands stops covering a crew. And the next hire is genuinely unclear, because the obvious answer (another plumber) is often not the right hire. What follows is what actually breaks and the order to deal with it, sitting under the wider guide on how a trade business grows past the owner.

The 3-van ceiling is a dispatch problem, not a demand problem

At 1 van, dispatch is your memory. At 2, it's your memory plus a phone call. At 3, your memory becomes the constraint on the entire business, and it fails in a specific way: the schedule is fine until 10am, then a hot water service dies in Prospect, and re-planning 3 people's days takes 40 minutes you don't have while you're under a house.

The symptoms are recognisable. Jobs get double-booked or forgotten. Customers ring to ask where the plumber is. Vans crisscross the metro area because nobody sequenced by geography. Someone finishes at 2pm and sits idle because the next job wasn't ready.

Each of those is a cost, and none of them appear on a profit and loss as "dispatch". They show up as fewer billable hours per van per day, which is the number that actually decides whether the third van pays for itself.

Fix the dispatch layer before adding the fourth van. That means jobs scheduled the day before, sequenced by suburb, with a deliberate gap for the emergency work you know is coming. It also means somebody other than the owner holding the schedule, which is where the hiring question starts.

The callout model: what it earns and what it costs

Emergency and callout work is the backbone of a lot of Adelaide plumbing businesses, and it's a genuinely good model. It's high-margin, it's urgent so price sensitivity is lower, and it produces customers who ring you again.

It also carries costs that rarely get counted.

• It destroys the schedule. Every emergency displaces planned work, and displaced planned work gets rebooked, which costs an admin conversation and sometimes a customer.
• It burns the crew. After-hours rosters wear people out. The plumbers who leave a growing business often leave because of the phone, not the pay.
• It hides the real hourly return. Travel across the metro at 9pm, diagnosis, a trip to get a part: the billable portion of a callout can be far lower than it feels.

The businesses that scale on callout work do 2 things. They protect a portion of the week for planned work so the base load isn't hostage to the phone, and they measure callout jobs separately: revenue per callout, billable share of the hours, and how many turn into a planned job later. If callouts aren't converting into repeat work, the model is a treadmill rather than a growth engine.

Moving off pure hourly pricing

Charging by the hour is honest, easy to explain, and it caps the business at the number of hours the crew can physically work. It also punishes speed: the better your team gets, the less you earn for the same job.

Moving off it doesn't mean abandoning it. It means recognising that different work suits different pricing.

• Repeatable jobs go to fixed price. A hot water unit changeover, a standard tap set, a basic cistern replacement. You've done hundreds. Price them from what they actually cost you, plus the margin you need, and the customer gets certainty.
• Diagnostic and variable work stays hourly, with a clear callout fee and an honest explanation of why.
• Larger works go to a quote, priced from a job costing history rather than a gut estimate.

The step that makes the change safe is knowing what a job costs you now. Without that, fixed pricing is guessing with consequences. What a job actually costs against what you quoted covers how to run that comparison, which is the input every fixed price depends on.

Stock, vans and the cash tied up in them

A plumbing business at 3 vans is carrying a warehouse it doesn't call a warehouse.

Every van holds stock. Multiply by 3, add the shed, and there's a meaningful amount of cash sitting on shelves and in van racking. Some of it turns over weekly. Some of it has been there since a job in 2023 that got cancelled.

The 2 questions worth asking are what's on the vans that never moves, and what's missing that causes a second trip. Both cost money, and the second costs more than owners expect: a return trip for a part is an hour of a plumber's day plus the customer's patience.

A stock list per van, checked monthly, is dull work with a fast payback. So is a standing arrangement with a supplier that keeps the fast-moving items available near where the crew actually works, rather than across town.

Apprentice, tradesperson or office administrator: which hire comes next

This is the decision that most often gets made backwards. The instinct at 3 vans is to hire a fourth plumber, because the work is there. Frequently the right hire is the person who answers the phone.

Work through it in this order.

What's the actual constraint? If the crew is idle because jobs aren't scheduled or parts aren't ready, another plumber adds a fourth idle person. If the crew is flat out and turning work away, capacity is the constraint and a tradesperson makes sense.

What is the owner's week spent on? Count it for 2 weeks. If most of the owner's hours go to answering the phone, booking jobs, chasing invoices and quoting at night, an office administrator buys back the hours that are currently choking the business. That hire also usually pays for itself faster, because it converts owner hours into either billable hours or into the quoting that wins work. The guide to stepping back from the tools works through that sequencing properly.

Can the business carry a multi-year commitment? An apprentice is the cheapest way to add hours and the longest commitment, and it only works where there's enough supervised work and somebody with the capacity to teach. Whether the business can carry a first apprentice covers that decision on its own, including the sources to check for the rules.

The honest general answer at 3 vans: administration first, then a tradesperson, then an apprentice once there's a qualified person with room to supervise. Reverse that order and the business gets busier without getting better.

The numbers to watch through the change

You don't need much, but you need it weekly.

1. Billable hours per van per day. The single most useful number in a plumbing business. If it drops when you add a van, dispatch is the problem, not demand.
2. Gross margin by job type. Callouts, planned work, renovations, maintenance. They're rarely as similar as they feel.
3. Quote conversion. How many go out, how many come back, and how fast you responded to each.
4. Debtor days. How long from invoice to money in, split by customer type. Builders and property managers behave very differently from a household.

Look at them together monthly. Any of them read alone will mislead you.

Where it usually goes wrong

The 2 common failures are worth naming.

The first is adding capacity to a broken system. A fourth van bolted onto a business where the owner is still the dispatcher, the quoter and the after-hours phone doesn't produce more revenue. It produces the same revenue with more cost, and an owner working later.

The second is growing on price. Winning the extra work by being cheaper leaves no room to pay a crew properly, and a plumbing business that can't pay well can't keep plumbers. In a labour market as tight as South Australia's, that's the constraint that ends the growth.

If you want the sector version of all of this, the plumbing coaching page sets out the problems Adelaide plumbing business owners usually arrive with, and what a first conversation tends to cover.