Watch any one of the scads of home improvement shows on TV, and you, too, might be inspired to take on your own at-home renovations. It’s fine if you have the tools and know-how. But too often, some homeowners think a successful attempt at organizing their closet gives them carte blanche to, say, build a new one.

“Homeowners find DIY projects so alluring because it can be a less expensive option than hiring a professional,” says Mike Bidwell, CEO of home services company Neighborly. “However, some projects can be costly or do more harm than good if attempted without the right professional expertise.”

Pros vs. Amateurs: What You Need to Know

Learning on the job is normally a good thing, but not necessarily when it comes to DIY home improvement. In fact, there are a number of projects that should be completely off the (work) table for amateurs. “Advanced plumbing, electrical work, structural changes and projects that require heavy lifting all pose potential safety hazards that DIYers cannot adequately prepare for,” says Bidwell.

Here is a longer list of projects that Bidwell says are too advanced for beginning DIYers:

Any wiring upgrades. Mark this under the “extremely dangerous” heading in home improvement, as it can lead to electrocution or fire damage. “Stay safe and ask a qualified electrician to upgrade or replace your home’s wiring,” Bidwell says.

Garage door spring repair. The right tools and techniques are needed to fix those torsion springs that are under tension. Otherwise, you risk bodily harm and property damage, Bidwell says.

Cleaning air conditioner coils. You’re fine to clean or replace your air conditioning filter, but stay away from those coils on the condenser unit unless you have special tools and adequate experience. Otherwise, you could cause more harm than good to your AC, which will result in a hefty repair bill, Bidwell says.

Repairing a gas appliance. Gas leaks and fires can be catastrophic, so leave your stove, oven and other gas-powered appliance fixes to the pros.

Water heater installation. A cold shower is the least of your problems. Make a mistake installing a new water heater, and you could be dealing with a major flood.

Property inspection. If you found your dream home, love might blind you from its imperfections. Bidwell says you need a professional home inspector to find the issues you can’t (or don’t want to) recognize.

Cleaning the dryer vent. Even though we walked you through how to clean a dryer vent, it’s a quicker project when the pros do it. Plus, this job tends to get put off easily, which isn’t a good thing. “Unkempt dryer vents can lead to life-threatening outcomes, from fires to the buildup of toxins, mold and bacteria,” says Bidwell.

Pest control. Citing mosquitoes specifically, Bidwell explains you might think you’ve got things under control with store-bought treatments, but if you’re wrong, “the process can be expensive and short-lived,” he says. It’s better to call a professional exterminator to keep these and other pests at bay.

Window tinting. Even if you can safely reach the window to apply the tinting, Bidwell says don’t do it. “Window film technology is continually evolving, and only experts can provide the best recommendations to find a tint that meets your specific needs,” he explains.

New deck installation. This is a heavily permitted project in many areas, like New York, and chances are only experienced pros can take it on. If you want to flex your DIY prowess, save it for restaining the deck in the off-season.

Installing an irrigation system in your yard and moving large mirrors or glass panes are two other projects that can lead to injury or property damage if fumbled, Bidwell says. He also recommends leaving any extreme interior design changes like new paint colors or creative storage solutions in the hands of an experienced designer or professional organizer – especially if you want long-term results that actually look good and work well for your home.

Even hiring a cleaning pro to do a deep clean of your home after you vacate can save time and provide peace of mind by checking off one more task on your lengthy moving to-do list, Bidwell says.

Don’t Try This at Home – Unless You Do This First

“Before committing to a DIY project, ask yourself if you have the time, tools, and talent to complete the project successfully,” says Mallory Micetich, home expert at home services company Angi. “A lot of DIY projects seem simple at first but actually require specialized tools and advanced skills.”

While it’s great to have a positive mindset when tackling any project, Micetich advises homeowners to consider the negative consequences should things not go according to plan with a DIY project. Not all projects have the same risk factor, of course. Did you mess up while painting a wall in your living room? You can fix it later. But make an error on a plumbing project, and there could be a flash flood in your house. “Before committing to a DIY project, make sure you’re comfortable with the risks,” she says.

Sound Advice from a Successful DIYer

Of course, this isn’t to completely dissuade you from trying out projects well within your wheelhouse. There are DIYers in every corner of the internet who are truly nailing it (pardon the pun). But even they’d tell you to do your research before diving in.

“DIY projects are a great way for people to create custom and unique items and to design a space they truly love,” says Erin Nutter, who runs The DIY Nuts blog with her husband, Eric. “However, DIY isn’t always easy.”

Here’s what Nutter recommends you think about before opening your toolbox:

Cost. Would-be DIYers tend to underestimate how much money they’ll save, if any. “You need to account for mistakes you may make with materials or new tools you may have to purchase to complete a project,” Nutter says. She does note that as you complete more projects, you will have the potential to save money because you’ve already amassed the tools, supplies and other materials. Until that time, she recommends borrowing or renting tools.

Safety. Paintbrushes are pretty innocuous. Paint ladders are a different story – quite literally, depending on how high up you’re painting. Regardless of the project scope, safety is a must. “Do a little extra research about the materials and tools you are using to make sure that you are doing it safely,” she says.

Timeline. Nutter says no matter the project, it’s going to take longer than you think it will. “Don’t rush the process, or you may be disappointed in the outcome,” she advises. “Take breaks when needed so that you can avoid making tired mistakes.”

Even with many completed projects under her own toolbelt, Nutter agrees that some are indeed best left to the pros – notably electrical, plumbing and tiling projects. “It is best to know what areas you are confident in and can complete safely for your family,” she says. “When in doubt, call a professional.”