Bathroom Renovation Mistakes: 10 Costly Blunders to Avoid Today
Step through the front door and walk past the kitchen. We are heading straight to the back of the house where the master bath is. Can you smell that? It is the scent of a homeowner who forgot to check for mold before they ordered five thousand dollars worth of Italian marble. My name is Gil. I spent over a decade fixing the messes people made when they tried to play contractor without a map. Now, I write about it so you don't have to live through a flooded crawlspace like I did back in 2014.
Renovating a bathroom is like surgery. It is expensive, messy, and if you cut the wrong thing, everything stops working. According to Remodeling Magazine’s 2023 Cost vs. Value report, a mid-range bathroom remodel costs an average of $24,606. You don't want to throw that kind of money down a drain that isn't even hooked up yet.
Why are you skipping the exhaust fan?
Look up at the ceiling. If you see a tiny, yellowed plastic square that sounds like a jet engine but moves zero air, you have a problem. Nine times out of ten, homeowners spend all their money on a fancy vanity and zero on ventilation.
- Check the CFM rating. You need at least one cubic foot per minute per square foot of room.
- Vent it to the outside. I once saw a guy vent his bathroom fan directly into his attic. Three years later, his insulation looked like a science experiment gone wrong.
- Don't buy the cheapest model. It will be so loud you will never turn it on, and then your new paint will peel in six months.
Moisture is the silent killer of every bathroom renovation.
Is your plumbing actually where you think it is?
Let's crouch down and look under the sink. People love to move toilets and showers to "open up the space." It sounds great on paper. In reality, moving a toilet three feet can add $2,000 to your bill because the joists are in the way.
I remember a job in Scottsdale where a client wanted to swap the tub and the vanity. We opened the floor and found the main stack was cast iron and brittle as a cracker. What started as a simple swap turned into a full-house replumb. If your layout works, keep it. Use that saved money for a heated towel rack or better tile.
Did you forget about the "wet" behind the walls?
Walk over to the shower. If you are just putting new tile over old greenboard, stop. That is a recipe for disaster. The National Kitchen and Bath Association (NKBA) suggests that the biggest hidden costs in any bathroom project are water damage and mold found after demolition.
- Use a true waterproofing system like Schluter-Kerdi or a liquid membrane.
- Replace the subfloor if it feels even slightly soft.
- Never trust a contractor who says "the grout will keep the water out." Grout is porous. Water goes through it like a screen door.
Why is it so dark in here?
Stand in front of the mirror. If the only light is coming from a single bulb behind you, you are going to hate shaving or putting on makeup. You will be working in your own shadow.
Layer your lighting. You need an overhead light for the whole room, but you also need sconces at eye level on either side of the mirror. It makes a world of difference. I once worked on a house where the owner installed a single, high-intensity floodlight in a small powder room. It felt like being interrogated by the police every time you went to wash your hands.
Are you buying "big box" fixtures to save a buck?
I know it is tempting to grab that $99 faucet from the local hardware store. Don't do it. Inside those cheap faucets are plastic cartridges and thin seals. Professional-grade fixtures from a plumbing supply house might cost double, but they have brass internals.
Think about it this way: a cheap faucet leaks while you are at work. It ruins your new vanity, your floor, and the ceiling in the room below. Was saving $100 worth a $5,000 insurance claim? Probably not.
Is the tile too big for the floor?
Look down at your feet. Large format tiles are trendy because they have fewer grout lines. They look sleek. However, if your floor isn't perfectly level (and nine times out of ten, it isn't), those big tiles will have "lippage." That is a fancy word for one edge sticking up higher than the other. It's a trip hazard and it looks terrible.
In a small bathroom, you need more grout lines on the shower floor anyway. It provides the grip you need so you don't slide like a hockey puck when the floor gets soapy. Stick to smaller tiles or mosaics for the wet areas.
Where are you going to put the towels?
It sounds stupid, but people forget storage all the time. They pick a pedestal sink because it looks "airy" and then realize they have nowhere to put the toilet paper.
- Recess your medicine cabinet into the wall.
- Build a niche in the shower for your shampoo.
- If you have the space, add a linen closet or a tall pantry cabinet.
I once had a client who spent thirty grand on a master bath and didn't include a single drawer. She had to keep her hairdryer in a basket on the floor. It drove her crazy within a week.
Did you hire the cheapest guy you found?
We are walking back out to the driveway now. See that beat-up truck with no magnets on the side? That might be the guy who quoted you half what everyone else did. There is a reason for that.
According to data from Angi, the average labor cost for a bathroom renovation can be up to 50% of the total budget. If someone is offering to do it for significantly less, they are cutting corners on things you can't see, like waterproofing or electrical safety.
I once found a raccoon living in the ductwork of a house because a "budget" contractor left a hole in the exterior wall for three weeks. The money the homeowner saved on labor went straight to the pest control guy and a new HVAC cleaning.
What is the plan for the mess?
Before you swing the first hammer, decide where the trash is going. A bathroom gut job creates a mountain of heavy debris. Old cast iron tubs weigh hundreds of pounds.
Rent a dumpster. Don't think you can just put it in heavy-duty trash bags and leave it on the curb. Most municipal trash services won't touch construction debris. Having a pile of old tile and a broken toilet sitting on your lawn for a month is a great way to make your neighbors hate you.
Are you following the trends too closely?
Finally, think about the future. All-black fixtures look cool today, but they show every single water spot and speck of dust. Ultra-modern designs can look dated in five years.
Stick to classic finishes for the expensive stuff like the tub and the wall tile. If you want to be trendy, do it with the stuff that is easy to change: the paint color, the cabinet hardware, or the towels. Your wallet will thank you when it comes time to sell the house.
Renovating is a marathon, not a sprint. Take your time, buy the good stuff, and for heaven's sake, make sure that exhaust fan actually works.