Repainting Walls and Ceilings: The Preparation That Makes Paint Last

In a Dhaka flat, repainting usually follows a problem: a ceiling stain after the monsoon, flaking paint behind a wardrobe, black spots in a bathroom. Paint is a thin film that only stays put on a surface that is dry, clean, sound and sealed, so most of a good repaint happens before the first coat.

Why paint fails early: the usual causes

• Moisture behind the paint. Dulux lists seepage through worn joints and leaks in roofs or walls among the main causes of peeling.^[7]
• Mould painted over instead of removed, which makes it more likely to come back.^[8]
• New plaster painted too soon. Fresh cement plaster is wet and alkaline; without a suitable primer, salts from concrete and brick can react with the paint.^[3]
• Loose, powdery or glossy old paint, or kitchen grease. New paint only sticks as well as the layer under it.^[6]
• The wrong paint for the room. Bathrooms and kitchens stay humid for hours a day, and ordinary emulsion may not resist mould there.^[4]
• No primer, or over-thinned paint. Porous plaster soaks up paint unevenly,^[3] and over-thinned or over-stretched paint leaves too thin a film.^[1]

Warning signs to read before you repaint

Dulux treats water stains and bubbling or peeling paint as early signs of hidden moisture and mould.^[8] If you see them, the painting should wait.

Deal with damp, leaks and mould first

Paint does not stop water. In many Dhaka buildings, damp comes from bathroom leaks in the flat above, monsoon seepage through outer walls and windows, the roof over the top floor, or condensation. Our guide to damp walls and water seepage explains how to tell these apart, and how to trace bathroom water leaks covers the most common source of ceiling stains.

The US Environmental Protection Agency (EPA) says to fix the water problem, clean off mould and dry the surface before painting, since paint over mould is likely to peel. It advises professional help for mould larger than about 10 square feet (roughly 1 square metre), and never mixing bleach with ammonia cleaners.^[9] See also how to prevent mould in bathrooms.

After the repair, give the wall time to dry; a soaked slab can take weeks in the monsoon. Berger's putty instructions set a maximum of 15% moisture, measured with a moisture meter.^[2] Without a meter, wait until the stain stops changing and the plaster looks evenly dry.

Ceiling stains and cracks

A water stain usually shows through ordinary emulsion, so once the ceiling is dry, seal it with a stain-blocking primer; paint makers such as Dulux sell one alongside their ceiling paints. Repaint the whole ceiling, because touching up a small area can make patchiness more visible.^[5] On a top-floor ceiling, suspect the roof: see how to inspect a flat roof before the monsoon.

Asian Paints suggests a crack filler for cracks up to 3 mm, and putty or a 1:3 white cement and fine sand mix for holes.^[1] Wide, diagonal or reopening cracks may mean structural movement; read which wall cracks need a professional inspection before painting over them.

Old paint, lead and dust

Scraping and sanding old paint makes fine dust. EPA warns that work disturbing old paint can release large amounts of lead dust, with young children most at risk,^[11] and WHO states that no level of lead exposure is known to be safe.^[12] Bangladesh has a 90 ppm limit for lead in paint, and large makers are reported to be mostly compliant, but a 2026 ESDO study found 68 of 161 samples over the limit, especially spray and industrial paints and small producers.^[13]

• Do not dry-sand, burn or heat-strip old paint of unknown origin. If you must sand, wet the surface first, sand the smallest area needed and clean up thoroughly.^[11]
• Keep children and pregnant women away, and clean up with damp cloths, not a broom.
• Do not strip large areas yourself; EPA advises against removing lead paint on your own.^[11]
• Buy decorative paint from established makers that state no added lead, as the Asian Paints primer data sheet does,^[1] and avoid industrial or spray paint indoors.^[13]

Tools and materials

• Dust sheets, masking tape and plastic for fittings and furniture you cannot move.
• Scraper, wire brush, medium and fine sandpaper, and a sanding block.
• Bucket, sponge and mild detergent or sugar soap for washing walls.^[6]
• Wall putty, crack filler and a putty knife.^[1]
• Alkali-resistant cement primer for bare plaster, and a stain-blocking primer for water marks.^[1]
• Interior emulsion, mould-resistant for bathrooms and kitchens.^[4]
• Brush, roller, tray and extension pole; Dulux suggests a 10–18 mm nap roller for most ceilings.^[5]
• A sound stepladder, safety glasses, gloves and a dust mask.^[1]

New plaster: wait, then prime

Asian Paints recommends letting new masonry cure for 28 days before priming,^[1] while Berger asks for at least two months of drying for best results, with 15 days as an urgent minimum.^[2] Follow your product's data sheet, and allow longer in the monsoon.

A cement primer seals porous, alkaline plaster so the finish dries evenly and resists alkali attack.^[1][3] One maker's system runs: sand, prime, putty, sand, prime again, sand lightly, then the finish coats.^[1] Treat new patches of plaster or filler in an old wall the same way, or they will show through as dull patches.

Step by step: repainting a room

1. Make sure leaks are repaired, damp has dried and mould is cleaned off.^[9]
2. Clear the room and cover what remains with dust sheets.^[6]
3. Mask around switches and sockets. If you remove a cover plate, switch that circuit off at the breaker first.
4. Scrape loose paint back to a firm edge.^[7]
5. Fill holes and cracks, let them dry and sand smooth.^[6]
6. Sand glossy areas dull, then wash off grease and dust and let the wall dry.^[6]
7. Prime bare plaster, patches and stains. Asian Paints quotes 3–4 hours between primer coats at 25 °C and 50% humidity; humid weather can slow this.^[1]
8. Mask edges and press the tape down firmly.^[6]
9. Paint the ceiling first. Cut in edges with a brush, then roll in sections about one metre wide while the edge is still wet.^[5]
10. Apply a second coat when the first is dry; many emulsions are designed for two.^[4]
11. Peel off the tape at an angle before the paint fully dries.^[6]
12. Keep the room ventilated, and never pour leftover paint down a drain.^[1][10]

On a ceiling, start in a corner and work across, then down. Dulux recommends finishing each section by laying off: drawing an unloaded roller across it in one direction without pressure.^[5]

Choosing paint for bathrooms, kitchens and ceilings

Paint makers sell finishes that resist mould on the dry film. Jotun describes its Fenomastic Hygiene emulsion as suited to humid kitchens and bathrooms,^[4] and Dulux sells mould-resistant kitchen-and-bathroom wall and ceiling paints.^[5][8] Paint cannot replace ventilation: without a working exhaust fan or window, mould returns. Asian Paints advises washing fungal growth off painted surfaces about every six months.^[1]

• Bedrooms and living rooms: standard emulsion; matt or low sheen hides small flaws.
• Kitchens: a washable emulsion with some sheen, easier to wipe clean.
• Bathrooms and their ceilings: a mould-resistant emulsion.^[4]

Ventilation, VOCs and ladder safety

Paints release volatile organic compounds (VOCs), solvents that evaporate as paint dries. EPA says indoor levels can be very high during use and can linger afterwards, causing eye, nose and throat irritation, headaches or nausea. It advises plenty of fresh air, following label precautions, buying only what you need and using methylene chloride paint strippers only outdoors or with good ventilation.^[10] Keep children and people with asthma out of freshly painted rooms.

Common mistakes and troubleshooting

• Painting over a stain before the leak is fixed.^[7]
• Painting over mould instead of removing it.^[9]
• Applying putty over old emulsion without checking the data sheet; some cement-based putties are not recommended there.^[2]
• Touching up part of a ceiling, or letting the edge dry between sections.^[5]
• Shutting the room to keep dust out, so solvent vapours build up.^[10]

If new paint blisters within weeks, scrape a small area. Damp plaster or salt crystals behind it point to moisture; dust or grease points to poor preparation. Either way, remove the failed paint, cure the cause and start again.^[7]

Do it yourself or call a professional?

What drives the cost of repainting

We could not find reliable published repainting prices for Bangladesh, so we give no figures. The cost depends on area and height (ceilings and stairwells take longer), the condition of the walls (scraping and putty can take longer than painting), damp repairs that must come first, the number of primer, putty and finish coats, the grade of paint, and how much furniture must be protected. Get written quotes from at least two painters listing the preparation, products and coats; see getting and comparing repair quotes.

Prevention: keeping new paint in good condition

Next steps

1. Walk round each room with a torch and note stains, peeling, mould and cracks.
2. Fix leaks and damp first, and wait until the surfaces are dry.
3. Decide what you will do yourself, and get written quotes for the rest.
4. Buy the right primer, putty and paint for each room, plus a sound stepladder.
5. Prepare thoroughly, then paint ceiling first and walls second, with windows open.