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Buying a home with an enormous backyard is a definite thrill. So much space! There's room for your dog, a swingset for your 5-year-old, and a deck! For many of us, this is the holy grail. And you -- you brave adventurer, you -- want to build it yourself.

And we've got faith in you. We do. But decks are a huge undertaking, and assuming you can get 'er done with just a drill and a good attitude is a near-guarantee of disaster. That doesn't mean you can't do it. It just means you need to pay extra attention with this DIY project. (And remember: Always consult your local building code first and research each element extensively before you start building.)

So, want to learn how to build a deck? Look out for these seven signs you're building your deck wrong -- and some expert tips on how to reverse course.

1. You're being unrealistic

Sorry, beginners. A deck should never be your first major construction project. Period. End of story. Just stop now. Hire a pro.

"You have to know what your skills are," says Rusty Meador, a contractor and handyman in Leland, NC. "If you've never built a small patio deck, then you're going to struggle with a 20-foot-by-10-foot patio deck."

There's something to be said for learning on the job, but building a major platform -- one that will eventually be filled with family and guests -- isn't the time. You don't want to put anyone's life in danger, do you? (This is a rhetorical question.)

"You're building something that not just has people walking on it, but could be loaded down with 4 feet of snow," says Kevin Pleasants, the operations manager for Handy, an on-demand handyman and housecleaning app. "Ideally, you should have worked with concrete before and be really confident with all sorts of leveling."

2. You didn't plan a footprint

Before you hammer that first nail, consider how you want to use your outdoor space. Will you eventually add a pool? Does the sun hit the east side of the yard, but not the west? Plan your footprint accordingly.

Here's why: If you don't pay attention to the layout of your yard beforehand, you can end up accidentally covering the vents for your washer or dryer or blocking sunlight to the bulkhead window in the basement.

"Plan that stuff out and understand where you want shade or privacy walls in advance instead of saying 'It's springtime!' and building," says Pleasants, also a former carpenter and deconstruction specialist for Build it Green.

3. You didn't call the utility company

"The biggest things I've seen go wrong can happen easily," Pleasants says. "You're in the back yard drilling holes to lay the cement, and you encounter water and gas lines."

Hitting a gas line will not only force you to take a long break from construction while it's being fixed, but it could also cause your beloved home to go boom. So make sure to dial 811 a few days before you dig to find out where utilities lines are buried.

4. You didn't build a proper foundation

Experts can't emphasize this enough: The No. 1 rule to building your own deck is to build a proper foundation.

"Honestly, it's one of the things that people figure out at the end and need help to fix," Pleasants says.

The specifics will depend on your locale, but as a general rule, you need to secure the concrete footings holding up your wooden pillars at least 3 to 4 feet beneath the ground, and 12 inches below the frost line -- otherwise the winter chill will leave your decking in shambles. And it's not just cold you need to worry about: Hurricanes can tear decks with poor foundation right out of the earth.

Sure, you can build a deck without paying attention to your foundation that "looks good as soon as it's finished, but you walk around on it and nothing stays level and chairs are tipping over," Pleasants says.

5. You're cutting costs

Speaking of safety: Building a deck is not the time to cheap out on supplies. Sure, you can pick up some inexpensive pine at your local home improvement store, but you'll regret it when it starts to rot one year in, requiring the careful replacement of every single board.

Make sure your wood is pressure-treated and your steel is galvanized, "otherwise all of this stuff will fail and you'll be playing catch-up," Pleasants says.

6. You're being careless with the railings

Railings are tricky to build, and even harder to build correctly. Your local building codes will likely specify requirements for baluster spacing and rail height. Make sure to follow their guidelines -- but also pay attention to ensure your work is solid.

"Making sure your railing is actually secure … is one of the hardest things to do," Pleasants says. You can't just nail balusters into the side of the outer joists -- you'll want to bolt the posts and use heavy-duty screws. "If it takes a big hit and someone bumps it, you could rip it straight out of the side of the joist. Do your research, and beef up your railing to make sure you're doing it right."

If you find this confusing, take the time to talk to an expert before you begin.

"Usually people can read enough online and figure it out if they're really committed, but handrails and stairs are where people really throw their hands up and call someone," Meador says.

7. You're scared to call in a pro

You can learn a lot online about building a deck. Check out the resources available at This Old House or Professional Deck Builder to get an overview of the process or to get answers to any specific questions you might have about stairs, foundations, or railings. But if you find yourself swimming in information, don't feel bad calling in a pro.

"People get a little too big for their britches, and if you're feeling overwhelmed it makes sense to call in someone who feels confident," Pleasants says.

For homeowners experienced in DIY projects, building a deck can be a fantastic advance-level summer project. But don't get in over your head: Building something designed to support anything from a few guests for a summer barbecue to a small wedding reception requires the highest level of attention and care.