Bathroom mold — at a glance
- Surface mold on grout, caulk, and the shower ceiling is common and usually cleanable.
- Mold that keeps coming back, soft drywall, loose tiles, or a musty smell from the vanity points to water behind the surface.
- The fix is ventilation plus leak repair — cleaning alone won’t hold if moisture keeps feeding it.
- Call (385) 250-2825 if you see the warning signs below.
Surface mold — cleanable
- Black or pink spotting on grout lines
- Dark spots on silicone caulk at the tub or shower edge
- Gray or black spotting on the ceiling above the shower
- Mold on the shower curtain or liner
Clean hard surfaces with detergent and water or a bathroom cleaner, scrub, rinse, and dry. Caulk with mold growing inside it can’t be cleaned — cut it out and recaulk once the joint is fully dry.
Warning signs of hidden water
- Mold returns within weeks of thorough cleaning
- Loose, cracked, or hollow-sounding tiles
- Soft drywall next to the tub or shower
- Peeling paint or bubbling on the wall behind the toilet or vanity
- Musty smell inside the vanity cabinet
- Stains on the ceiling below a second-floor bathroom. See ceiling water damage.
- Soft or spongy floor around the toilet base
These usually mean a failed shower pan, a leaking drain, a supply line, or a wax ring under the toilet. The Edgemont case study on this site started with a failed shower pan.
Common causes
Poor ventilation
No exhaust fan, an undersized fan, or a fan that vents into the attic instead of outside. Run the fan during showers and for about 20 minutes after.
Shower pan or tile failure
Cracked grout and failed waterproofing let water into the wall and subfloor on every shower.
Toilet wax ring
A failed seal leaks a little on every flush. The subfloor rots slowly and mold grows underneath.
Supply lines and drains
Slow drips under the vanity soak the cabinet floor and the wall behind it.
How Vault handles bathroom mold
- Inspection with moisture meters and thermal imaging to find wet areas behind tile and drywall.
- Find and fix the water source — or coordinate with your plumber.
- Containment — sealed containment, HEPA negative air, zipper entry — so spores don’t spread to the rest of the house.
- Remove affected materials, clean framing, and dry to standard.
- Post-remediation clearance before rebuild.
Typical Utah cost
| Scope | Typical range |
|---|---|
| Surface mold, caulk and grout, DIY | Under $50 in supplies |
| Behind-vanity or small wall section remediation | $800-$2,500 |
| Shower wall or subfloor remediation | $2,500-$6,000 |
| Full bathroom tear-out with mold | $5,000-$12,000+ |
Vault’s mold inspections start at $99; remediation jobs start at $500.
Bathroom mold that keeps coming back?
Call (385) 250-2825. We’ll find out if there’s water behind the wall.
Mold remediation services · Mold vs mildew · Mold in basement · Mold in attic
More guides: Bathroom exhaust fans and mold · Sweating pipes
Need help with mold in Provo? Our Provo mold remediation crew is AMRT-certified, and remediation jobs start at $500. Call (385) 250-2825.