Planning a bathroom remodel that holds up for decades

Two bathrooms can look the same on the day they're finished and age very differently. One stays dry and solid for decades. The other starts showing loose tile, stained grout or a soft floor within a few years. The difference is almost always in the prep work behind the walls, so that's where this guide spends the most time.

Refresh, full remodel or moving fixtures

Start by deciding how deep the project goes. Most bathroom projects fall into one of three levels:

Moving the toilet is usually the most expensive change. It has a large drain that has to slope correctly, and in a house on a raised foundation or a slab, that can mean cutting into the floor or crawling underneath. Code also sets minimum clearances around a toilet, so a move in a small room can run into them. If the current layout works, keeping it frees up budget for better materials.

Tub-to-shower conversions

Replacing a tub with a walk-in shower is one of the most common bathroom projects in LA. It makes the room easier to use, especially for anyone with bad knees or limited balance, and a larger shower often fits in the same footprint as the old tub.

A few things to think about first:

• Keep a tub somewhere. Families with young children often want at least one tub in the house. If this is your only bathroom, think about who will live there next.
• The drain moves. A tub drain usually sits at one end. A shower drain is often moved to the center or replaced with a linear drain along one side, which means floor work.
• The valve may change. A new shower valve with a pressure-balancing or thermostatic cartridge protects against sudden temperature swings.
• Glass and niches. Decide on the door or fixed panel and any built-in niche or bench before framing, so blocking and waterproofing are planned around them.

Waterproofing: the part you never see

Waterproofing is the single biggest hidden-quality issue in bathroom remodeling. Tile and grout are not waterproof. Water passes through grout and soaks whatever is behind it. If the layer behind the tile isn't built correctly, water reaches the framing and subfloor, and you find out years later from mold, rot, loose tile or a stain on the ceiling below.

A properly built shower has a continuous waterproof layer behind the tile on the walls and under the floor, tied into the drain. Contractors use a few different methods:

• Traditional mortar bed with a liner. A sloped mortar base, a waterproof liner, then a second mortar bed on top. Proven over many decades when done carefully.
• Sheet membranes. A thin waterproof sheet bonded over the backer board and floor, with sealed seams and corners.
• Liquid membranes. A coating rolled or brushed on in layers to a specified thickness.
• Foam board systems. Lightweight waterproof wall boards and pre-sloped shower bases, sealed at every joint.

Each method works when it's installed the way the manufacturer specifies. Problems come from shortcuts: skipped seams, a missing layer around the valve or niche, or the wrong backer board.

Slope matters too. A shower floor should fall toward the drain so water never sits in a corner, commonly about a quarter inch per foot. Too flat and water puddles. Uneven and you'll see standing water near the glass.

Choosing tile

Porcelain tile is the workhorse for bathrooms. It absorbs very little water, holds up to cleaning products and comes in nearly every look, including stone and wood. Ceramic tile is softer and usually less expensive, and it works well on walls. Natural stone, such as marble, looks beautiful but needs sealing, can etch from some cleaners, and is more slippery when polished.

For the shower floor and bathroom floor, slip resistance matters more than looks. Small tiles, like mosaics, have more grout lines, which give your feet more grip and follow the slope to the drain more easily. Large tiles look clean on walls but need a very flat surface, which adds prep time.

Grout is part of the decision. Standard cement grout needs sealing and can stain. Epoxy and other premium grouts resist stains better and cost more to install. Ask your tile setter what they recommend for the shower.

Order 10 to 15 percent extra tile for cuts and breakage, and keep a box after the job for future repairs. Discontinued tile is hard to match.

Curbless showers and aging in place

A curbless shower has no step at the entrance. The floor slopes gently toward the drain, so you can walk or roll straight in. It costs more than a standard shower because the subfloor often has to be lowered or rebuilt to get the slope without a curb. In return, the bathroom works for you at any age, and for visitors who use a walker or wheelchair.

Even if you don't need grab bars today, have the crew install solid wood blocking inside the walls around the toilet, the shower and the tub while the walls are open. It adds very little to the job. Later, grab bars can be screwed into solid framing anywhere you need them, instead of into drywall anchors that can pull loose.

Other features that help later in life:

• A handheld shower head on a slide bar
• A built-in bench or a spot for a fold-down seat
• A comfort-height toilet
• Lever handles instead of knobs
• A wider door, if the wall allows it

Fixtures, fan and electrical

Toilets. California limits how much water a new toilet can use per flush, so any toilet sold here meets the standard. Wall-hung toilets save floor space and make cleaning easier, but they need a carrier frame in the wall and a thicker wall, so decide before framing.

Vanities. Stock vanities are quick to get. Semi-custom and custom vanities fit odd spaces and offer more drawer storage. Floating vanities make a small room look larger. Pick the faucet and sink together, because the faucet's reach has to match the basin.

Shower and faucets. Choose the valve brand early. The valve goes in during rough-in, and the trim you pick later has to match it.

Ventilation. A bathroom with a shower or tub needs an exhaust fan ducted to the outside, not into the attic. Moist air dumped in an attic leads to mold. California code calls for a fan with humidity control in these bathrooms, so it runs until the room dries out. The fan should be sized to the room. A fan that is too small or too loud tends to get ignored.

GFCI protection. Outlets in a bathroom need GFCI protection, which cuts power in a fraction of a second if current leaks. It's a code requirement and an important safety feature near water.

Heated floors. An electric mat under the tile warms the floor and makes the room comfortable on cold mornings. It needs its own circuit and a thermostat, and it has to be installed before tile. Decide early, because adding it later means removing the floor.

Permits and how long it takes

A bathroom generally needs a permit when you move or add plumbing, add electrical circuits, change the framing, or replace a shower or tub down to the studs. A cosmetic refresh, like swapping a vanity and faucet in the same spot, often does not. Rules vary by city, so check before you start. In the City of Los Angeles, that means the Department of Building and Safety (LADBS). Elsewhere in the county, check with your city or with LA County Building and Safety. Our permit guide explains the different paths.

A typical bathroom remodel goes in this order:

1. Design and selections, including tile, vanity and fixtures
2. Permit
3. Protecting the rest of the house, then demolition
4. Rough plumbing and electrical, then the city inspection
5. Waterproofing, shower pan and backer board
6. Tile on the walls and floor
7. Vanity, toilet and fixtures
8. Glass door, lighting, fan and paint
9. Final inspection and walkthrough

Construction on a bathroom remodel typically takes 3 to 8 weeks in Los Angeles County. A refresh with the layout unchanged sits at the short end. Moving fixtures, a curbless shower, custom glass or a slow inspection push it longer. Design and permits can add anywhere from nothing to about six weeks. Custom glass is measured after the tile is done and can take a couple of weeks to arrive, so expect a short wait near the end.

If it's your only bathroom

Many LA homes have one bathroom, and remodeling it means planning for weeks without a shower. It's manageable with some preparation.

• Ask the contractor to keep the toilet working, or to reset it each evening, for as much of the job as possible.
• Ask whether a temporary toilet on site is possible during the stages when the old one has to come out.
• Arrange showers elsewhere, such as a gym, a neighbor, family nearby or a short stay during the wettest stages.
• Ask which days the water will be shut off for the whole house, and plan around them.
• Pick every finish before demolition, so the crew never waits on a decision and the room is out of service for less time.

If you're planning to add a second bathroom someday, it can make sense to build that one first and remodel the original afterward.

Questions to ask your contractor

Bring these to the first meeting. Clear, specific answers are a good sign.

• Which waterproofing system will you use in the shower, and do you follow the manufacturer's instructions for it?
• Will the shower pan be flood tested or inspected before tile?
• Can I see photos of the waterproofing before it's covered?
• Will you add grab-bar blocking in the walls while they're open?
• Where will the exhaust fan duct to, and does it have humidity control?
• Which parts of this job need a permit, and who pulls it?
• How will you keep a toilet working if this is our only bathroom?
• When does the glass get measured, and how long does it take to arrive?
• What happens if you find rot or water damage under the floor?
• What is included in the price, and what is listed as an allowance?

For license checks, contracts and payment rules, read how to hire a contractor.

Common questions