How do I grow my plumbing business past five trucks?

There is no five-truck hump, at least its not a physical limitation. There is a productivity band, and it decides everything. At coached plumbing shops the middle half of technicians produce somewhere between $350K and $553K a year. Multiply either end of that band by five trucks and you get two companies that are not remotely in the same business, all with the same headcount and the same fleet.

So when an owner says they are stuck at five trucks, the truck count is almost never the thing that is stuck.

The hump is real, the number is not

Ask around and you will get a different ceiling from everyone. Forums will tell you four trucks can be more profitable than five, and that six and seven are better than five again. One trade publication puts the plateaus at one to three, four to eight, and ten plus. Consultants place the wall at $1.5M, at $2M to $3M, at $1M to $5M. All of them are describing something real, and none of them agree on where it is, because they are all pointing at a symptom.

The feeling is consistent even when the number is not. Revenue climbs, the owner works more, and the money at the bottom does not move. Sometimes it goes backwards. That experience is real. The truck count is just the most visible thing in the room when it happens.

Three mechanisms that actually cause it

1. Overhead arrives in steps, not on a slope

Revenue grows a little at a time. Overhead does not. It sits flat and then jumps. Sometimes wildly as a percentage of sales.

Somewhere around this size you cross thresholds that each add a fixed cost overnight. You need a real dispatcher rather than whoever is nearest the phone and the dispatch board. You need a second bay, or a yard, or actual storage. You need someone doing the books; not you at 11pm. You need a service manager because you can no longer ride with every tech. None of these are optional and none of them scale down.

The shops that get hurt are the ones that add the truck first and do not plan how that affects their overhead requirements. Revenue goes up by one truck's worth, overhead goes up by a dispatcher plus a truck, increased rental space, and other overhead contributors. The owner concludes that five trucks is a cursed number. What actually happened is that they paid for the step without the potential volume to carry it.

2. The dispatch ratio quietly inverts

Under about four trucks, dispatch is a person who also does other things besides just dispatching, and it works. Past that, the number of daily decisions grows faster than the truck count does. This compounds with required customer interactions and starts to overload your dispatch.

When dispatch is under-resourced, techs wait. They are assigned to the wrong priority calls. They arrive with the wrong part because nobody staged it. The owner sees a busy board and assumes capacity is full, when in truth every tech is losing an hour a day to coordination that nobody owns. That lost hour is invisible in every report you look at, and it is the single most common reason a five-truck shop produces like a three-truck shop. Efficiency starts to tank.

3. The spread between your best and worst truck

This is the a big one problem, and it is measurable today.

Rank your technicians by revenue produced over the last twelve months. In most shops at this size, the top producer does close to double the bottom one. That is consistent with the coached-shop distribution, where the gap between the bottom quarter and the top quarter is wide enough to represent an entire additional technician's output.

Sit with that. The difference between your best truck and your worst truck is often larger than the revenue the next truck would add. You are considering a capital purchase, a hire, an insurance increase, and a fixed monthly payment, in order to buy something you already own and are not collecting. Instead ask yourself can you increase the performance of the team, before adding the additional truck.

Understand your KPI's

Three numbers, and you can pull them this week.

Revenue per tech, ranked. Not the average. The list, worst to best. Note the gap between top and bottom, and compare each tech against the coached-shop averages above. Anyone below the bottom quartile is your first project to decide if you are going to coach up or out.

Close rate per tech. The coached median is 73.6%. A tech producing low revenue with a healthy close rate and average ticket has a dispatch or volume problem. A tech producing low revenue with a weak close rate has a training or motivation problem. Those are different diseases with the same symptom, and treating one as the other wastes a quarter.

What we recommend

Do not add the sixth truck. Not yet.

Close the spread first. Take your bottom two producers and work the specific problem they have. This will require ride-alongs to further understand the issue and a focus on a service system process. Dispatch might require a closer look to ensure that we are getting the best qualified technicians to the best opportunities they are suited to. Give it a quarter and and focus on a goal to hit. This is the cheapest capacity available to you and it requires no capital, just tracking and coaching.

Then resource dispatch properly, before the next truck rather than after it. A shop where every tech loses an hour a day to coordination does not need to buy its way out with more trucks, instead you need to improve the efficiency.

Then, when your existing trucks are producing near the top of the band and you are genuinely turning work away or losing to cancellations, add the truck. It will be more profitable starting sooner, because it is joining a company that knows how to convert and how to dispatch.

The owners who break through are not the ones who found the magic truck number. They are the ones who stopped counting trucks and started measuring what each one produces.

To find out which of the three mechanisms is yours, take the free scale-readiness assessment. Short, no account required.