There are many simple maintenance tasks you can perform on your own. But when it comes to major home repairs, there are certain things you shouldn’t attempt yourself. Here are the top five house repairs that are best left to a professional:

1. Plumbing Repairs

Most plumbing repair projects require a professional. That’s because even a small leak can cause thousands of dollars in additional home repair costs. Rerouting sewer pipes and extending or moving hot water lines should always be left to an expert. Something as small as an incorrectly sealed water line can cause major structural damage to your home. Plus, there are many safety requirements set forth by the Uniform Building Code that most DIY-ers are unaware of. Most plumbing projects aren’t dangerous, but they can go horribly wrong really fast, so it’s best to leave them to a pro.

2. Electrical Repairs

Many do-it-yourselfers can install a ceiling fan or change a light switch. However, most electrical repairs carry a high risk of electrical shock and should only be completed by experienced electricians. Some electrical home repairs even require special permits before the work can be done. In these cases, you have no choice but to get home repair help from a professional.

3. Wall Removal

It may seem like a simple task, but most walls are either structurally important, or they contain pipes or wires that you may not know about. If your home improvement project requires the removal of a wall, be sure to consult an expert. This is especially true if your home contains asbestos, which should only be removed by a professional.

4. Roofing Projects

Much like electrical and gas repairs, safety is the number one concern in roofing repair projects. Roof repair requires sure footing and substantial experience. You may be able to replace a single shingle or fix a certain section of your gutter, but beyond that you’ll need a specialist. Even if you don’t hurt yourself in the process of trying to repair your own roof, there’s a good chance you won’t do the work correctly. This can lead to water damage, high heating and cooling bills, and expensive home repair costs down the road.

5. Gas Appliance Repairs

Projects that require you to move, repair or work around gas appliances should always be approached with extreme caution. Remember, whenever gas is involved, a single mistake can have harmful or even deadly consequences. Approach appliance repairs with knowledge and respect–hire a knowledgeable repair authority.

Before you start any house repair project, ask yourself these three questions:

1. Have I done anything like this before?
2. Do I feel comfortable with this project?
3. Is the project I’m about to start completely safe?

If you answered no to any of these questions, you most likely need to consult a professional.