There are a lot of savvy, motivated homeowners whose favorite three letters of the alphabet are DIY. These hearty souls enjoy tackling projects, solving problems, and reveling in the satisfaction of a job well done.

But even these folks should be aware of home improvement jobs that are NDIY (Not-Do-It-Yourself). Here are seven tasks that should generally be left up to the pros.

“Sir! Please put down the hammer and step away from the project!”

1. Category: Electrical

What you can get away with: Installing a ceiling fan, changing a light switch (if you turn the power off first)

Hire a pro for everything else because: One false move with electricity, and you are injured or dead and/or your home burns down. A licensed electrician knows how to avoid these pitfalls, and will also make sure any wiring-related repairs are up to code.

2. Category: Plumbing

What you can get away with: Changing a showerhead, repairing a leaky sink pipe

Hire a pro for everything else because: It may not be as dangerous as electrical work, but it could get ten times as messy. Leaving a leak in a joint or improperly connecting pipes together may be just enough for water to drip/trickle out and cause hundreds — or even thousands — of dollars in damage.

3. Category: Tree removal

What you can get away with: Cutting up downed logs, paring back limbs and branches overhanging your roof

Hire a pro for everything else because: Cutting trees isn’t hard, but getting them to fall where you want them is. You run the risk of trees landing on your home, power lines, or telephone wires — or even other people.

“It’s a tree, honey. What could possibly go wrong?”

4. Category: HVAC repair

What you can get away with: Changing filters or installing a new thermostat

Hire a pro for everything else because: The heating/air conditioning system (especially the heat pump) is one of the most complex networks of machinery in the modern home. If you do something wrong, not only do you still have the existing problem, but you may have voided whatever is left of your manufacturer’s warranty.

5. Category: Gas piping

What you can get away with: Um… nothing, pretty much.

Hire a pro for everything else because: You may think that you’ve done it right because there’s no evidence that anything is wrong … until a gas leak renders you unconscious or leads to a fiery explosion. So connecting a gas stove to a pipeline — or even disconnecting an appliance from a gas line to move it — is best left to the pros.

6. Category: Roof repair

What you can get away with: Replacing a few broken or missing shingles, fixing eaves

Hire a pro for everything else because: If you have substantial roof damage (especially from a recent storm), there may be structural issues which need to be addressed that you may not see. Plus, the longer you work on a roof, the higher the chances of falling and hurting yourself.

The view from the vantage point of a guy who thought he could fix his roof all by himself.

7. Category: Gutter cover installation

What you can get away with: Putting flimsy, store-bought screens over your gutters (which won’t do you much good anyway)

Hire a pro for everything else because: A comprehensive, effective gutter protection system (like Gutter Helmet) requires a trained professional (like Harry Helmet) to install it properly. And you’ll never have to clean your gutters again!

Written by Chris Martin