Bathroom Renovation Guide

1. Demolition: Remove existing tile, fixtures, vanity, and toilet. This is when you discover the condition of the subfloor, framing, and existing plumbing.
2. Rough plumbing: Move or add supply lines, drains, and vent pipes. If you're changing the layout (moving toilet, adding second sink), this is the expensive step.
3. Rough electrical: Add or move circuits for exhaust fan, lighting, GFCI outlets, heated floors. All wiring runs happen while walls are open.
4. Cement board or moisture barrier: Cement backer board (Kerdi, Durock) replaces drywall in wet areas. This is the most critical waterproofing step. Never tile over standard drywall in a shower.
5. Tile: Shower walls first, then floor. Proper waterproofing membrane behind shower tile is non-negotiable. Floor tile should have appropriate slip resistance.
6. Fixtures: Shower valve trim, showerhead, faucets, toilet installation.
7. Vanity: Installed after floor tile (or with cutout for vanity) and before plumbing hookup.
8. Mirror and accessories: Mirror, towel bars, toilet paper holder, shelving.
9. Paint: Final coats on walls and ceiling after all dusty work is complete.

Slip resistance matters for floors: Look for tiles rated with a COF (Coefficient of Friction) of 0.42 or higher for wet areas. Small mosaic tiles with more grout lines provide better traction than large format tiles on shower floors.

Grout selection: Epoxy grout costs more but is virtually waterproof and stain-proof. Cement-based grout is cheaper but requires sealing and re-sealing over time. In showers, epoxy grout is worth the investment.

Where spending more pays off:

• Shower valve: A pressure-balancing or thermostatic valve prevents temperature swings when someone flushes a toilet. Cheap valves don't do this. This is inside the wall — you can't easily upgrade later.
• Toilet: A quality toilet ($300–$600) flushes better, clogs less, and lasts decades. The cheapest toilets ($100–$150) use more water per flush and clog more frequently. Comfort height and elongated bowl are worth the upgrade.

Where it doesn't matter as much:

• Basic sink hardware: A $150 faucet and a $400 faucet perform identically in most cases. The premium is for finish quality and design, not function. The exception is the cartridge — Moen and Delta have excellent cartridge warranties.

Proper ventilation is the single most important factor in preventing mold and moisture damage in a bathroom. A cheap or undersized exhaust fan creates chronic mold problems that can spread into wall cavities.

CFM calculation: For bathrooms up to 100 sqft, you need 1 CFM per square foot. An 80 sqft bathroom needs at least an 80 CFM fan. For bathrooms over 100 sqft, add 50 CFM for each toilet, shower, and tub. A large master bath with a shower and soaking tub may need 150+ CFM.

Sone rating: This measures noise. Look for fans rated 1.0 sones or lower for quiet operation. A quiet fan gets used; a loud fan gets turned off — which defeats the purpose.

Venting: The fan must vent to the exterior — not into the attic. Venting into the attic dumps moisture into your insulation and roof structure, creating rot and mold above your head.

Humidity-sensing fans: Worth the $30–$50 premium. They turn on automatically when humidity rises and shut off when it drops. You'll never forget to turn the fan on again.

• Moving a toilet: The most expensive plumbing move in a bathroom. Toilets connect to a 3–4" drain line that runs to the main stack. Moving it more than a few feet requires breaking through the floor (or ceiling below) to reroute the drain. Budget $2,000–$5,000+ for the plumbing alone.
• Moving a sink: Moderate cost. Supply lines are easy to extend, but the drain line needs proper slope to the stack. Budget $500–$2,000 for the plumbing.
• Adding a shower where none existed: Requires significant plumbing (supply, drain, vent), structural work (shower pan, waterproofing, cement board), and may require a larger water heater. The most complex addition to a bathroom. Budget $5,000–$15,000+ depending on access and existing conditions.

The cost-saving principle: Keep fixtures in their current locations whenever possible. Every fixture that moves requires plumbing changes that add thousands to your budget.

• Grab bar blocking: Install solid wood blocking behind shower walls during renovation — even if you don't need grab bars now. Adding blocking later means tearing out tile. The blocking costs almost nothing during a remodel but hundreds or thousands to add later.
• Curbless showers: A curbless (zero-threshold) shower entry is easier to enter for all ages and abilities. It requires a linear drain and careful floor slope but adds significant accessibility and resale appeal.
• Wide doorways: A 32–36" clear doorway opening accommodates mobility aids. Standard bathroom doors are 24–28" — widening during a renovation is the time to do it.
• Comfort height toilet: 17–19" seat height vs standard 15" is easier on knees and more comfortable for most adults. Minimal cost difference for significant usability improvement.

Universal design features add value to any bathroom and cost very little to include during a renovation. They add significant resale value as the population ages.