Amy Carnrick bought a million-dollar commercial plumbing company, grew it tenfold, and sold it for six times EBITDA in 5 years. Now, she's sharing what she learned — and what she'd tell every trades business owner thinking about an exit.
Amy has bought and sold three businesses across three industries. She's built from near-zero and exited at the top. She's navigated the kind of transactions most business owners only go through once in a lifetime, and she's done it enough times to know that the exit is never really the end. It's the result of every decision that came before it.
Her most recent chapter is the story of Foster Plumbing, a commercial plumbing company she acquired, grew tenfold in five years, and ultimately sold to a private equity firm for six times EBITDA.
On paper, that might sound clean and easy to pull off, but what really happened behind the scenes to achieve that level of success wasn't simple.
Amy worked for a year without a single day off, building systems from scratch in an industry she'd never worked in, training apprentices, and earning trust. Read on to learn more about her hard-won success, what she did (and didn't do), and what you might adapt for your business today.
The Road to Foster Plumbing
Amy didn't come from the trades. She came from a career of figuring things out as she went: buying businesses in industries she didn't know, learning what she needed to learn, and moving on when the chapter was done.
Her first business was a chiropractic clinic. Then came a residential handyman service, a business she started so she could drop her kids off at school in the morning and pick them up in the afternoon. She ran it for a couple of years, sold it, and eventually landed in medical device sales, selling orthopedic devices to surgeons, negotiating with hospital purchasing departments, and learning how every level of a large organization actually makes money decisions.
While I may have been a bit braver in my younger days, venturing into those fields without prior experience, I can now share the deep insights of buying and selling businesses based on those experiences." Amy Carnrick
When Amy's eldest son decided college wasn't for him, she saw it as an opportunity rather than a problem. She'd spent years in the handyman business struggling to find reliable plumbers, and she knew the demand wasn't going anywhere. She advised him to learn the trade, and he did. When he earned his journeyman's license, Amy started looking at plumbing companies to buy, not for herself, but to set him up for his future.
"I didn't think I was going to sell. So I was building for the future — building my company for the future. I planned to leave the business to my children. To leave a legacy." Amy Carnrick
She'd assumed she'd buy a residential company, something closer to the handyman world she already knew. But when a commercial plumbing company specializing in tenant improvement construction came on the market, the numbers told a different story. Commercial margins were better, the work was steadier, and the ceiling was higher. Amy bought Foster Plumbing.
It was doing about a million dollars a year. The previous owner had been running at his personal capacity — pen-and-paper accounting, no real systems, and a critical problem Amy didn't discover until after the deal closed: he was also the company's only estimator. When he walked out the door, that knowledge walked out with him.
"I learned very quickly that I was in big trouble because I didn't know what I was doing. The former owner was the estimator — he didn't really communicate that, and I didn't know to ask that question." Amy Carnrick
Most people would have panicked. Amy had already survived enough business crises to know that panic doesn't fix anything. Instead of panicking, she started building.
Building the Machine
Without a reliable scheduling system and with a learning curve steeper than she'd anticipated, Amy overbooked her crew. In the trades, that's not just an inconvenience; it's a trust violation. Her people were stretched thin, and she knew it.
Amy didn't make excuses. She stood in front of her team and made a promise.
"I did not overbook you intentionally, but I promise I will do everything within my power to make sure it never happens again." Amy Carnrick
Then she went about keeping that promise, and it nearly broke her doing it.
For the better part of a year, Amy worked fourteen-hour days without a single day off. She was learning commercial plumbing from the ground up, building operational systems that didn't exist, and making every major decision alone.
She handled bookkeeping she wasn't naturally suited for. She navigated supplier relationships with the same hard-nosed approach she'd learned in medical device sales — becoming, by her own admission, the most difficult customer her supply house had ever dealt with. And in every spare moment, she was building something she believed in, which was not just a profitable company, but a vibrant culture.
"You have to be willing to suffer. That's the difference; most people are not willing to suffer. And what people don't realize is, you’ve just got to show up when there's nobody else." Amy Carnrick
Amy wasn't in it for just the money. She wanted to elevate the trades. After all, her son had become a plumber.
She'd watched apprentices in the industry get treated poorly, dismissed as disposable labor rather than the future of the business. She didn't allow that at Foster. She invested in training, treated apprentices as essential to the company's future, and built a culture where a plumber would never feel "less than" for being a plumber. At the time, she wasn't planning to sell. She was building for the long haul, and the apprentices who trained under her and went on to become master plumbers are still some of the people she's most proud of.
"The apprentices that are now master plumbers are my favorite folks. It's fun to watch them leave. One reached out and said they were about to go out on their own!" Amy Carnrick
But culture alone doesn't produce a 29% net margin. Systems, people, and processes do.
Early on, Amy went searching for software. She'd never heard the term "field service management," so she sat at her computer and typed in "plumbing estimator," "labor management," "estimating software." What she found was Simpro. And what she did with it went far beyond what most users ever attempt.
Over the next several years, Amy built Foster's operations on top of Simpro with a level of depth and intention that set her company apart. She constructed a catalog of more than seven thousand parts, each with vendor options and photos.
She built over 300 pre-builds (templates for common jobs that made estimating dramatically faster) with a philosophy that reflected how she thought about everything: include every part you could possibly need, then delete what you don't. That way, nothing gets missed.
She built a custom labor calculator, fed by data in Simpro from thousands of completed jobs, that allowed her to take estimating power away from any single person and put it into the system itself. That was a deliberate move. When she'd first arrived at Foster, the estimator held all the power in the company, and Amy saw this as a bottleneck. By building systems that codified the knowledge, she made sure the business could never again be held hostage by one person's expertise.
She also used Simpro's price discrepancy report to hold suppliers accountable on every invoice. In commercial plumbing, the person who quotes you a price at the supply house is rarely the person who invoices you. Amy caught overcharges that most companies never even notice, and she sent the discrepancy report to her supplier every week until they finally hard-coded her pricing just to stop dealing with the corrections.
"That price discrepancy report — I saved and recuperated everything Simpro cost me and more. Much more. The person who quotes at the supply house does not invoice, and they will invoice you full price. They hope that you don't keep track of it. But with Simpro, we did." Amy Carnrick
The result was a commercial plumbing company that general contractors trusted on sight. Amy charged roughly 20% more than her competitors and won jobs consistently, because her team showed up, delivered what they promised, and had the systems to prove it. The business grew from $1 million to $10 million in five years. Foster's net margin reached 29%, well above most competitors in the space.
But that growth came at a cost.
"It is lonely at the top. I used to think that when people said that, it was sort of an arrogant thing to say. No. It is lonely at the top. Because sometimes you're making decisions and you're like, damn, I'm not sure if this is the right decision, but my staff has to trust me. So I can't be like, hope this is right, guys, let's just try this." Amy Carnrick
By the time she had 40 employees, Amy felt she'd reached her own capacity. The stress, the hours, the isolation of making every consequential decision alone. She got sick. Health, she would later say, was the real ceiling.
Every business owner has a capacity — a dollar sign attached to the level of complexity they can manage before something has to give. The previous owner's capacity had been $1 million. Amy's was $10 million. She's honest about that, even though she knows most entrepreneurs would never admit it.
"I honestly feel that at the time, I was at my personal capacity at $10 million. It was going to take somebody else to take it to the next level, somebody who could think differently than myself." Amy Carnrick
She had built something worth buying. The question was whether she'd built it in a way that someone would actually pay what it was worth. As it turned out, she'd been preparing for that answer for years without even realizing it.
Listening to the Market
Amy didn't wake up one morning and decide to sell Foster Plumbing. The decision came in pieces, over years, shaped by conversations she wasn't even planning to have.
When she first bought the business, the plan was to keep it in the family. She'd build it up, hand it to her children, and leave a legacy. But plans have a way of changing when other people are involved.
"While my plan was to leave the business to my children and leave a legacy, those plans changed because their desires changed. So I was left to sell." Amy Carnrick
Before she ever formally engaged a banker, Amy started paying attention to the inquiries that come in to every business owner who's been around long enough. The unsolicited emails. The cold calls from buyers testing the waters. Most owners ignore them or get annoyed. Amy listened, and what she heard changed the shape of her business.
"I know there were a couple of days where I was just like, I'm selling this thing. So I called a few of those emails that we all get. And they said, well, we want this, or we want that. And I actually listened. A lot of them said, we want more service revenue out of your business before we're interested. So, I paid attention to that, and I opened up a service division." Amy Carnrick
That decision, made years before the actual sale, fundamentally changed what Foster Plumbing was worth. Amy could have expanded in any number of directions: industrial work, med gas, or other specialties. But the market was telling her what it valued, and she chose to listen rather than follow her own instincts.
In the trades, the difference between a project-based business and a service-based business isn't a minor detail. According to Blake Nielsen, Amy's investment banker and co-founder of Black Iron Advisors, it can be the difference between getting paid and getting paid well.
"For firms that are largely project-based or entirely project-based, the multiple is potentially half what it would be if you were to do a very high percentage in service revenue. Values are reflective of the perceived risk. Service is a lower perceived risk because it's more likely to be recurring. The investor believes your company is likely to persist in five years and still be servicing those clients." Blake Nielsen, Co-Founder, Black Iron Advisors
Amy grew Foster's service division to roughly 30% of revenue by the time she sold. She also had to manage another risk factor that buyers care deeply about: customer concentration. Her largest customer accounted for about 20% of total revenue, a threshold she'd been told never to cross.
"My customer was at about 20% of our total revenue, and I was always told that's the magic number, never go over 20%. And it is hard to do, especially when it's somebody who keeps feeding you lots of business. So you do have to fight that a little bit if you know that you're going to sell." Amy Carnrick
And then there was the question every buyer asks, whether they say it out loud or not: what happens when the owner leaves? Blake was direct about this.
"Most trades entrepreneurs are still responsible for 15 things inside the company when they should really be responsible for two. And the more you build out that team, and the more that you make it appear that you can walk out the door, and that the company will continue to grow and thrive even without you there, the more somebody is willing to pay for it. Because it looks lower risk." Blake Nielsen
Amy had been building toward this without fully realizing it. She'd already taken estimating power out of the hands of any single person and put it into Simpro.
She'd built systems that codified institutional knowledge so it lived in the business, not in her head or anyone else's. And her approach to customer relationships turned out to be an unexpected asset.
As a woman in a male-dominated industry, Amy hadn't built her client base through the fishing trips, football games, and hunting weekends that are common in the trades. Her relationships lived within the company and its reputation for showing up and delivering, not within her personal social network. That turned out to be exactly what buyers wanted to hear.
"In my experience, entrepreneurs are reluctant to let go of customer relationships. The problem is, if you want to transition out of the company over any reasonable time period, that will scare an acquirer. The owner leaves, and now that key customer has left. So the more you can diversify those relationships within the company, the better off you are. Amy was able to put every one of the potential buyers at ease." Blake Nielsen
The Sale
When Amy was ready to go to market, she engaged Blake Nielsen and Black Iron Advisors to represent her. Blake is a sell-side investment banker, meaning his job is to represent the seller and maximize their outcome. That distinction matters more than most business owners realize, and Amy had learned that lesson the hard way while interviewing potential advisors.
"It's very important that whoever you choose to represent you fully understands accounting. I had one of the people I interviewed tell me I needed to go back and refile all my taxes. I quickly walked away, because I knew I had filed them properly. The fact was they couldn't understand my taxes because they were so complex." Amy Carnrick
Finding the right representation was only part of the equation. Amy also needed a CPA with M&A experience and an attorney who had done deals like hers before. Blake's advice to business owners is blunt on this point.
"If they haven't been doing it for a long time, don't use them. You want somebody that does this day in, day out." Blake Nielsen
With her team assembled, Amy told Blake to go broad. Some sellers want a quiet, targeted process to protect confidentiality. Amy wasn't worried.
"Let's go out to a larger audience. I'm confident with my business and my customers. They're not going anywhere." Amy Carnrick
Black Iron went out to approximately 450 qualified potential investors. Of those, 82 signed nondisclosure agreements. Twelve submitted indications of interest, and not a single one of those 12 looked the same. Every offer had a different structure, a different vision for what Foster Plumbing could become under new ownership. Amy received two preemptive letters of intent from buyers who didn't want to wait for the full process to play out.
The process moved faster than the typical six to nine months Blake tells clients to expect. Preemptive offers can accelerate the timeline, but buyers who want to move fast still have to pay for the privilege.
The real test came during due diligence, the phase where the buyer verifies everything you've claimed about your business. This is where many deals fall apart or get renegotiated downward. For Amy, this meant opening the books entirely. She'd used QuickBooks and attached every single receipt, so when diligence came, she simply gave the buyer's team access and let them dig.
"If you failed your diligence, people see increased risk. So they're willing to pay you less. They end up saying, hey, I know what I offered you, but I'm going to take that back. Now my number is this, materially less than whatever they offered you up front. If you can avoid that because you had the right systems in place, absolutely, that's only going to help you." Blake Nielsen
This is where Amy's years of building systems paid off in a way she may not have anticipated when she was spending those 14-hour days constructing her Simpro catalog and tracking every supplier invoice.
The data was there. The financials were clean. The systems could be demonstrated, not just described. When buyers asked about backlog, pipeline, and job history, the answers lived in the system, not on a whiteboard or spreadsheets.
"We have a client right now who's got a very big business, but his backlog is literally a whiteboard in his office. And he's like, yeah, I've got a great backlog, it's right up here on this whiteboard. I sit back and go, great, but what was it a year ago? Because I can't tell somebody there was a great backlog if I can't measure it against what it was a year ago. Which goes back to systems, process — all of that." Blake Nielsen
Amy achieved a stock deal at six times EBITDA. For context, in her previous businesses in other industries, a 3x multiple was considered a strong outcome. The trades market has shifted significantly over the last decade, driven by an influx of private equity money that has pushed multiples higher than they've ever been.
"Historically, trades businesses transacted either with the rich guy down the street or within their own company. An existing employee, the second in command, or a family member. Because there was relatively limited external appetite, that constrained valuation. Twenty years ago, if I saw a subcontractor or trades business, I'd say it's a 3x trade all day. What's happened over the course of the last 10 years is there's been an influx of private equity money into the space." Blake Nielsen
Amy is candid that she doesn't think these elevated multiples will last forever. But her outcome wasn't just a product of favorable market timing. It was the result of years of deliberate preparation: building recurring revenue, managing customer concentration, investing in systems that could survive the scrutiny of a quality earnings report, and assembling an advisory team that knew how to present all of it.
The tax structure mattered too. Amy was able to execute a stock deal, which she calls the Holy Grail in the US. The person she originally bought Foster from wasn't as fortunate.
"A stock deal in the US, I think, is the Holy Grail, which is what I was able to do. People must understand what they're getting into. The owner that I bought it from was taxed on the sale 45%. There goes all your hard work." Amy Carnrick
She'd also wanted to explore selling to her employees, but ultimately couldn't make it work.
"That would have been my heart's desire, to sell to my employees. Number one, I didn't have anyone who could actually be a CEO. But number two, employees I've found were not able to understand the value of a business. They just had a certain number in their head that they felt was worth it, and they don't understand that there's an actual process behind that." Amy Carnrick
What Comes After
After the sale closed, Amy didn't retire. She started advising with Simpro. It wasn't a random career move. She'd spent years building her business on top of the platform and understood, from an operator's seat, what it could do when fully utilized.
But the reason she took the role goes deeper than product knowledge. Amy had been through the process of buying, building, and selling a business three times. Each time, she'd learned something the hard way that she wished someone had told her earlier. The Exit Ready webinar was her idea, not Simpro's.
"I initiated this webinar specifically for customers and to open it up to trade company owners, because I believe it's critical for business owners to fully understand the worth of their business and why. That way, you can take steps to increase your value." Amy Carnrick
Blake's advice for anyone watching from the sideline, whether a sale is five years out or five months, is to start building your team and cleaning up your house earlier than you think you need to.
"Start trying to build your team earlier than you think you need to. Start putting together your accounting advisor, your attorney, and your investment banker earlier than you think you need to. Because there are some things where we can say, ‘Oh, hey, you're still using cash basis accounting in a project-based trade. That's going to be a problem." Blake Nielsen
Amy's story is one version of how this can go, and she'll be the first to remind you that every single one of her six transactions looked different.
But the through line is consistent: the owners who build with intention, who listen to the market before they need to, and who invest in the systems and people that make a business run without them are the ones who get to choose their terms when the time comes.
For the full conversation between Amy and Blake, including live audience Q&A with trades business owners asking about seasonality, bottom-line growth, employee sales, and more, watch the Exit Ready webinar
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