Too many entrepreneurs treat their businesses like a DIY project: They want to do it all themselves. But a business is not a bookcase or backyard chicken coop.  It's a demanding, ongoing, ever-changing entity. Sooner or later, your workload reaches a critical point where you simply cannot do it all yourself.

As an entrepreneur, you're used to doing many jobs yourself. Indeed, according the Small Business and Entrepreneurship Council (SBE), 51.6 percent of small started out in the founder's basement or garage. But could your instinct to go it alone be holding back your growth?

A small business is officially defined as one with 500 or fewer employees. Even if your business is much smaller and you're not in a position to staff-up permanently, there comes a time when you need to hire consultants. Whether they're taking on legal, accounting, operations or human resources, many entrepreneurs try to do too much and end up learning some hard lessons.

1. When you're outside your area of expertise.

As a business owner myself, I learned my lesson early. I started my firm in 2007, during one of the biggest recessions ever. Excited about working with a new client, I drew up quick agreement and didn't pay legal counsel to review it. Full disclosure: I studied communications, not law! Many hours and $35,000 worth of work later, I lost that client when he claimed bankruptcy, leaving me $35,000 in arrears. After that, I spent the money to make my contracts fool-proof --- even from myself.

2. When there's more work than you can handle.

Executive Coach Michael Cooper has worked with his share of entrepreneurs, mostly heads of Silicon Valley Startups. They are driven, competitive, and, according to Cooper, slightly nuts.  "I love working with entrepreneurs, because we all are a little crazy." Cooper explains. "I mean that in an endearing way, but that 'I can take on anything attitude' makes you extremely vulnerable. You're more likely to make mistakes, especially when you're overworked."

Every entrepreneur occasionally takes on too much. It's built in to our go-getter DNA. But that personality trait can work against us when the devil is in the details. Better to recognize when you need help than to ask for it too late. Even Anthony Bourdain orders take-out sometimes. 

3. When you need a fresh perspective.

Working alone tends to make us set in our ways. A consultant can often help you see your blind spots. As Cooper says of his own consulting business, "We help you see your potential and spot potential roadblocks."  

Moving too fast, making assumptions, cutting corners, trying like mad to check off a box on your to-do list - it's easy to get lost in this flurry of activity. "Having an outside perspective," Cooper insists, "Can change the way you communicate with yourself and others." 

Opening yourself up to new opinions early on will help keep you from becoming the type of leader that surrounds themselves with yes-people, never an effective way to manage a business.

4. When you're entering uncharted territory.

If your company is facing a new challenge, it could be the right time to seek help from someone with a core competency your company lacks.  Maybe the challenge is a major acquisition, launching a new product line, or facing a tough issue that can do real reputational damage. If the stakes are high, you may want to get a few different opinions. 

5. When the stakes are too high to take a risk.

You may be at the top of your game, and ready to tackle this challenge in a world-class way. But are you sure? How do you know?

A consultant can bring third-party credibility and validation to a new project, potential investment or unfamiliar tactic. Just don't let them run the show. Make sure they present a well-supported, logical case for their recommendations and see if you agree. If case studies would bolster their advice, ask to see some. Sometimes, if you can afford it, a second opinion may be worth the expense. Ultimately, the final decision is up to you. It is, after all, your business.