A small room with a recurring problem
Grey or black spots on a bathroom ceiling, usually above the shower and in the corners, are one of the most common reasons people call a painter for a single room. Painting over them looks fine for a few weeks. Then the spots come back through the new coat. A job that lasts includes cleaning, drying and dealing with the moisture, and that's what a proper bid prices. We don't publish prices; this guide explains what goes into them.
First question: how big is it?
Pennsylvania's Department of Health puts the decision about who cleans mold in terms of size and health. Its fact sheet says a person without health problems can clean mold themselves when the area is less than 10 square feet, but that a contractor should clean it when the area is more than 10 square feet or the person has asthma, COPD, is pregnant or has other health issues.
For most bathroom ceilings, the spotting is a patch in a corner or a ring above the tub. If it's larger, or if anyone in the house has those health concerns, the cleaning itself may be a separate job before any painting. Ask the painter whether they'll clean the area or expect it to be cleaned before they arrive. That affects both scope and price.
No state rulebook for mold
The same Department of Health fact sheet (updated September 2026) states that there are no federal or Pennsylvania state regulations about mold. That means there's no state standard a painter is working to when they clean a mildewed ceiling. What you're paying for is their method, so ask them to describe it.
Cleaning and drying
A typical method for surface mildew on painted drywall includes:
- protecting the floor, tub and fixtures;
- washing the area with a mildew cleaner and rinsing;
- letting the surface dry fully, sometimes overnight with a fan running;
- checking that the drywall underneath isn't soft or stained through.
If the drywall is damaged, repair or replacement of that section comes before primer. Our surface preparation guide covers drywall repairs.
The moisture source
Bathrooms grow mildew because steam settles on cool surfaces and stays there. Things that change the cost of a lasting job:
- The exhaust fan. A fan that's missing, undersized, or venting into the attic instead of outdoors lets moisture linger. Fixing it is usually work for someone other than a painter, but it's worth knowing before the room is painted.
- A leak above. A stain shaped like a ring or a drip line can mean a leak from a bathroom or pipe upstairs. Fix that first.
- Cold corners. Ceiling corners against an exterior wall or attic may be cooler and collect condensation.
A painter who asks about these is trying to keep you from paying twice.
Primer and paint
After cleaning and drying, stained areas usually need a stain-blocking primer so the marks don't bleed through. The top coat should be a paint made for bathrooms, typically a satin or semi-gloss with a mildewcide. It's a more specialized product than ordinary ceiling paint. See our sheens guide for why a bit of gloss helps in a steamy room.
Small rooms, slow work
A bathroom has little open wall and a lot of cutting in: around the vanity, mirror, toilet, tub surround, light fixtures and the fan grille. Painters often take fixtures down or mask them carefully. Labor per square foot is higher than in a bedroom, and the room has to dry between coats with the door open and the fan on.
Questions for the painter
- Will you clean the mildew, or should it be cleaned before you start?
- How will you make sure the area is dry?
- Do you see signs of a leak or a ventilation problem?
- Which primer and which bathroom paint will you use?
- How long until we can shower again?