where bathroom tiles meet bathroom ceiling there's ?

Score and pull the old bead out with a silicone removal tool or flat scraper 2. Clean the gap with methylated spirits and let dry bone-dry 3. Re-apply a new anti-mould bathroom silicone - look for one that says "sanitary" and "anti-mould" like Dow 785+ or UniBond Anti-Mould 4. Leave it 24 hours before painting near it. Don't paint the silicone itself.
If the mouldy area is bigger than about 1m2, keeps coming back quickly, or smells musty in the plaster, get it checked - could be a leak or condensation issue.

Clean and treat the mould first, then let the area dry completely. If the mould is on the silicone, it’s best to remove and replace the silicone rather than paint over it. Then use a bathroom/mould-resistant ceiling paint.

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To tackle this issue properly before painting, you need to treat the mould and properly seal the gap between the tiles and the ceiling.
Here are the recommended steps:
1. Remove Mold & Old Caulk: Scrape away any moldy caulk in the corner using a knife or caulk remover tool. Clean the entire ceiling with a dedicated mold remover spray (or a diluted bleach solution) and let it dry completely.
2. Stain Block: Apply a coat of stain-blocking primer (such as Zinsser Cover Stain or Zinsser Bulls Eye 1-2-3) over the watermarks and water stains on the ceiling so they don't bleed through your new paint.
3. Re-Caulk: Apply a fresh bead of high-quality, mold-resistant sanitary silicone sealant or paintable acrylic caulk along the joint where the tiles meet the ceiling.
4. Paint: Once dry, paint the ceiling using a durable, moisture-resistant bathroom emulsion paint.

?Remove Mouldy Caulk: Cut away the damaged, mouldy caulk along the tile-to-ceiling joint using a utility knife. Mould embeds into old sealant and cannot be painted over effectively.
?Treat & Clean: Spray the area with a specialist mould remover (or a bleach solution), scrub clean, and let it dry completely.
?Paint the Ceiling: Use a stain-blocking primer (e.g., Zinsser Cover Stain) over water marks or residual stains, then apply two coats of mould-resistant bathroom paint.
?Reseal the Joint: Once the paint is completely dry, apply a fresh bead of sanitary silicone sealant (or mould-resistant flexible acrylic caulk) along the tile line to seal the gap.

Need anti mould zinzer

Clean the ceiling with a mould-killer (like Zinsser or bleach/water), scrape off any flaking paint, and ensure it is fully dry.

clean and treat the whole ceiling with the appropriate Zinsser anti-mould paint firstly before then applying correct paint for a wet area.

To fix a grubby-looking bathroom ceiling and address moldy caulk before painting, you must first eliminate the mold and stabilize the surface. Painting directly over mold or soap residue will cause the new paint to peel or the mold to grow back through the finish.

Kill the mold with bleach, replace bad caulk, then use mold resistant primer and then use bathroom or kitchen paint

Clean the mould properly
Wipe the affected caulk with a mould remover or a diluted bleach solution. Let it dry fully.

Treat the area
Dab a small amount of Zinsser BIN, Zinsser Perma-White, or any anti-mould primer onto the cleaned area so the mould can’t bleed back through the paint.

Lightly sand the ceiling
Just enough to smooth the surface where washing caused patchiness.

Spot-prime any stained or uneven parts
Use a stain-blocking primer or even a quick-dry multi-surface primer on any patchy areas.

Paint the ceiling with a mould-resistant bathroom paint
Two coats will give an even finish and help prevent future mould.

Clean mould and stainblock using a solvent based undercoat. Once undercoat is dry, 16hrs, apply a coat of Zinsser B.I.N Primer. Allow 45mins to dry and apply the ceiling paint.

You must kill the mould — not just wipe it — or it will bleed through new paint.

What to use:

A mould and mildew cleaner (e.g. HG Mould Spray, Zinsser Mould Killer, or diluted bleach: 1 part bleach to 4 parts water).

Spray or dab it on the affected area.

Leave for 10–15 minutes, then gently scrub with a cloth or soft brush.

Rinse with clean water and allow to dry completely.

Wear gloves and ventilate the room.

Clean the area with water and bleach then let it dry after that apply a stain block primer paint or spray, then coat over with anti mould paint or atleast bathroom paint and that should work fine.

Hi,
I suggest remove caulk, clean areas and apply new antimould caulk, and would paint ceiling and caulk in anti mould paint.

Clean the mold spots on the caulk with a bleach and water solution, then let it dry completely. If the caulk is damaged, remove and replace it with mold-resistant caulk. Apply a mold-resistant primer on the ceiling before painting, then use mold-resistant paint designed for bathrooms. This will improve the look and help prevent mold from coming back.

Where Bathroom Tiles Meet the Bathroom Ceiling – Mould and Painting Advice

It’s quite common for the ceiling above a bath or shower to develop marks or mould over time, especially where the tiles meet the ceiling, as this area is prone to moisture buildup. The material you're seeing is likely caulk or sealant, which may have been used to bridge the gap between tiles and plaster.

Before painting the ceiling, here’s what you should do:

Clean thoroughly – Treat any mould spots using a mould remover or a mixture of diluted bleach and water. Make sure the area is well-ventilated during this step.

Remove and replace damaged caulk (if needed) – If the mould is embedded in the sealant or it's peeling/cracked, it’s best to scrape out the affected caulk and replace it with a mould-resistant bathroom sealant.

Prep the ceiling – Lightly sand any rough or stained patches, then wash the entire ceiling with sugar soap or a mild detergent to remove residue.

Apply a stain-blocking primer – This will help prevent any marks from bleeding through the new paint and give better adhesion.

Use a mould-resistant paint – When repainting, choose a bathroom-specific ceiling paint that contains mould inhibitors for long-term protection.

By properly preparing the area, your fresh coat of paint will last longer and resist future mould growth.

For the Ceiling:

Lightly sand the affected area to remove any streaks or marks from washing.

Wipe with sugar soap and rinse with clean water to remove residue.

Let it fully dry before painting.

For the Mouldy Caulk:

Apply mould remover or diluted bleach on the mould spots.

Wipe clean and let it dry completely.

If the caulk is still discoloured or deteriorating, cut it out and replace it with an anti-mould bathroom sealant.

2. Prime & Paint
If Stains Are Still Visible: Use a stain-blocking primer

Use the Right Paint: Choose mould-resistant bathroom paint

Apply Two Coats: Allow full drying time between coats to prevent condensation issues.

First I would treat the Ceiling with anti fungal
Paint but you need to check that it not distemper if so it needs washing down then apply some stabiliset to the Ceiling before you paint it

To properly address the issue before painting your bathroom ceiling, follow these steps:
1. Use a mould remover or a mixture of one part bleach to three parts water.
2. If the ceiling dried with streaks or uneven patches after washing, lightly sand the surface with fine-grit sandpaper
3. Apply a mould-resistant, stain-blocking primer
4. Use a mould-resistant bathroom paint

Remove the existing caulk and replace with new before painting

1. Clean the Surface Properly
• Remove any grease or residue: Use a sugar soap solution or a mild detergent and water to clean the entire ceiling again. This helps remove any marks left from the initial wash.
• Treat the mould: Mix one part bleach to three parts water, apply it to the mouldy spots with a sponge or cloth, and leave it for 10–15 minutes. Wipe clean and let it dry. Alternatively, use a mould and mildew remover.

2. Address the Caulk Issue
• If the caulk is badly mouldy or peeling, it’s best to remove and replace it with a mould-resistant bathroom caulk before painting.
• If the caulk is still in good condition after cleaning, let it dry thoroughly before painting over it.

3. Prime Before Painting
• Apply a stain-blocking primer (such as Zinsser BIN, Zinsser 123, or a mould-resistant primer) over any problem areas to prevent stains from bleeding through.

4. Choose the Right Paint
• Use a mould-resistant bathroom paint with anti-mould properties to help prevent future issues.

Put zinsergard on the ceiling as paint. Caulk should not be applied on bathroom ceilings it should only be silicone. Then make sure to use bathroom. Paint for the ceiling

Clear the area, sand down the paint, apply bathroom paint anti mould and and reseal with new sanitary silicone