6 Bathroom Renovating Mistakes Contractors Are Begging You to Stop Making

Focusing on bathroom remodeling ideas is always a great way to kick off your project. But knowing what to avoid is just as important.

We spoke to contractors and custom home builders to get their take on bathroom renovating mistakes you should try to avoid.

Poor Space Planning

Awkward door swings, insufficient clearance, poor storage options, or improper placement of vanities and toilets make any bathroom feel cramped and inconvenient.

“A bathroom should be beautiful, but it should also be highly functional,” says contractor Yarin Gani.

When it comes to small bathrooms, space planning isn’t just a good idea—it’s critical. Where inches matter, good planning can make all the difference between a door that clears the toilet and one that won’t fully open or close.

Work with a professional, such as a designer, contractor, or architect, so they can help you optimize the flow of the space.

Ignoring Ventilation

A major bathroom renovating mistake is not planning for ventilation, says contractor Roi Omer.

“Since bathrooms are high-moisture environments, adequate ventilation is crucial,” he says. “Poor ventilation leads to mold growth, peeling paint, and could lead to structural damage if ignored.”

You can avoid this problem by installing a high-quality bathroom exhaust fan appropriate for the size of the room. Also consider which areas produce the most moisture, so you can position the exhaust fan appropriately.

Improper Waterproofing

Airborne water can be removed with an exhaust fan, but bathrooms also have plenty of water coming from other sources—showers, tubs, or sinks, as well as condensation on the toilet tank and on the walls. 

“Failing to address waterproofing properly can lead to costly issues like mold, mildew, and water damage,” Gani says.

Many homeowners assume standard drywall or low-grade waterproofing are good enough, but cutting small corners here can mean big trouble down the line.

The solution is to invest in high-quality waterproofing membranes behind tiles, especially in the shower or tub area. It’s a relatively inexpensive upgrade that protects your investment for long-term durability, Gani says.

Ignoring Functionality

“There are many homeowners who gravitate toward stylish and trendy details and items without fully considering how they will function on a daily basis,” Omer says.

Omer says that you can avoid this renovating mistake simply by listening to your contractor and designer.

“Work directly with them to create a layout that takes things like storage and lighting into consideration,” he says.

It’s also important to consider where the plumbing lines will run and the positions of the electrical outlets.

Choosing the Wrong Materials

“Homeowners sometimes select flooring, cabinetry, or countertops based solely on looks, without considering how they’ll hold up against moisture, humidity, and frequent use,” Gani says.

Installing a wood bathroom vanity or selecting porous stones that easily stain are a few prime examples. If you want that wood vanity, be sure to seal it properly. If you want that porous stone, apply sealant before you use it, as well as every year or so throughout its use.

Even better is to choose durable, water-resistant materials designed for high-moisture environments. Porcelain or ceramic tile is a great flooring option, and quartz countertops are low-maintenance and resistant to staining.

Not Future-Planning

Omer observes that homeowners typically plan for the moment but don’t plan for the future.

“They often redesign their bathroom based on their current lifestyle,” Omer says.

Instead, they should consider universal design principles, such as wider doorways and a curbless shower to improve accessibility. These features future-proof your bathroom without compromising its current aesthetic.