Take the dust off a wall dry before any water touches it, then wash once with a cloth wrung almost dry, and leave freshly painted walls alone until the paint has cured. Drywall dust is mostly gypsum. Wet it while it's still sitting on the wall and it turns into a thin grey paste that smears across the paint and dries as streaks, which is why so many people wash a wall after a renovation and find it looks worse.
Dry tools come first, and each one does a different job
- A vacuum with a soft brush attachment
- Lifts the loose layer from walls, ceilings and the tops of door frames without throwing it back into the room. After renovation work, Health Canada suggests a vacuum with a HEPA filter where possible, because that filter traps small particles.
- A dry microfibre cloth, or a flat microfibre mop on a pole
- Picks up the film the brush leaves on smooth paint. When the cloth turns white, shake it out outdoors or swap it for a clean one.
- A soft, clean broom or long-handled duster
- Reaches stairwells and high walls when the vacuum wand won't. Slow strokes keep the dust on the bristles instead of in the air.
- Two buckets
- One holds warm water with a few drops of mild dish soap, the other plain rinse water. With a single bucket the water goes grey after one wall and every wipe puts dust back on.
Gypsum dust is fine enough to clog an ordinary vacuum filter within a room or two. Empty the canister and check the filter between rooms, and do it outside or on a balcony so the dust doesn't settle on what you've just cleaned.
How much water a wall can take depends on the paint's sheen
The shinier the paint, the more washing it tolerates. If you don't know what's on the wall, look along it at a low angle toward a window: flat paint shows no reflection, gloss shows a clear one.
| Sheen, and where it often goes | How to wash it | What goes wrong |
|---|---|---|
| Flat or matte: ceilings, bedrooms, living rooms | Mostly dry dusting. Spot-wipe a mark with a cloth wrung until it feels nearly dry, using no pressure. | Rubbing polishes a shiny patch into the paint that shows in side light and doesn't come back out. |
| Eggshell: living areas, hallways | A damp cloth with mild soap and light strokes, then a clean damp cloth to rinse. | Heavy pressure in one spot leaves a dull or glossy mark. |
| Satin: hallways, children's rooms, family rooms | The same as eggshell, and it handles a second pass. | Soap left on the wall dries as a haze. |
| Semi-gloss or gloss: trim, doors, kitchens, bathrooms | A damp cloth or sponge with mild soap, then a towel straight away. | Water marks and streaks show up on shiny paint if it air-dries. |
Try your mix first on a hidden spot, such as behind a door or inside a closet, and let it dry before you judge it. Skip abrasive pads, powdered cleansers and strong solvents on any sheen: they cut into the paint along with the dirt.
New paint gets dry dusting only until it has cured
Paint that's dry to the touch can still be soft underneath, and a wet cloth on it lifts colour or leaves a shiny track. The label on the can gives the time before a wall can be washed, and your painter can tell you the date for each room. Until then, dust gently with a dry microfibre cloth or leave the wall alone.
Fresh paint also gives off fumes while it cures. Health Canada lists latex paints among the household sources of formaldehyde, and it says humid rooms make products release it faster. Its advice on painting is short:
Make sure there is plenty of ventilation during major painting or varnishing projects.
Its renovation page adds that windows and exhaust fans should stay in use after the work as well as during it, and that children, pregnant people and vulnerable adults are best kept away from the work area.
Wash one wall at a time, in strips, from the ceiling line down
- Lay an old towel along the baseboard. Wet gypsum that runs into the gaps of a hardwood floor dries hard and is a nuisance to get back out.
- Vacuum the ceiling first, then the wall from the top, then the top edge of the baseboard.
- Wring the soapy cloth until it stops dripping. Wipe a strip about as wide as your reach, from the top of the wall to the bottom.
- Rinse the cloth in the plain bucket before it goes back into the soapy one, and change the rinse water as soon as it turns cloudy.
- Go over the same strip with a cloth dampened in clean water, then dry it with a towel before you start the next one.
- Switch on a lamp and look along the wall from the side. A streak gets a buff with a dry microfibre cloth, not another wet pass.
- Do the switch plates, door frames and baseboards last, since anything that drips lands on them.
Working with a cloth this dry, drips are rare. If one does run down a dusty patch, wipe it up straight away before it dries into a line.
The marks left after drywall work each come off a different way
Joint compound smears and splatters
Let them dry completely. Most lumps flick off with a plastic scraper or a fingernail, and the powder that's left comes away with a dry cloth. Dampen only the spot itself, because compound softens again with water and spreads into a wider haze if you wash the whole area.
Ladder and tool scuffs
A drop of dish soap on a damp cloth lifts most of them from eggshell, satin and gloss. On flat paint, test first and stop as soon as the mark fades, since hard rubbing removes paint along with the scuff. A mark that won't lift on flat paint is usually a touch-up job for the painter.
Paint specks on trim, switches and glass
Latex paint that's still soft wipes off with warm soapy water. Dried specks on window glass come off with a plastic scraper held flat; on painted trim, leave anything that doesn't lift with a damp cloth. Our guide to grease on kitchen cabinets covers cabinet finishes, which react differently from wall paint.
Ceilings
Ceilings are usually flat paint, so they get the dry treatment and very little else. In an older home, Health Canada lists ceiling and floor tiles and plaster among the materials that may contain asbestos, and it says homes built before 1991 may have lead-based paint. If old ceilings or walls were cut or sanded and nobody tested them, read our notes on renovation dust in older homes before anyone sweeps.
Walls are one part of a post-renovation clean, so plan them together
Once the walls are done, the dust they shed has to come off everything below them. PavMa's post-renovation cleaning covers all accessible surfaces, baseboards, doors and door frames, windowsills, switches, handles and accessible air vents, cabinets and built-in storage, then vacuuming the full floor, mopping the hard floors and a final quality check. The service page asks that new paint and finishes are ready to be cleaned, so include the painter's wash date when you ask for a quote.
Mention flat paint, wallpaper, fresh wood trim or any other delicate new material too, along with which rooms had work and which only collected dust. Photos sent on WhatsApp help prepare the free estimate, and the scope of work is confirmed before the cleaning begins. If only one room was renovated and the rest of the home is overdue, look at deep cleaning as well. Visits run Monday to Saturday, 8 AM to 7 PM. Use the post-renovation quote form or call 437-889-1213.
Washing walls after drywall sanding and painting
Can I use a household vacuum on drywall dust on the walls?
You can, with a soft brush attachment, but the fine gypsum dust clogs an ordinary filter quickly, so empty the canister and check the filter between rooms. After renovation work Health Canada suggests a vacuum with a HEPA filter where possible, because it traps small particles.
How long after painting can walls be washed?
The label on the paint can gives the time before the surface can be washed, and your painter can give you the date for each room. Until then, dust the wall gently with a dry microfibre cloth or leave it alone, because a wet cloth can lift colour from paint that is still curing.
Why are my walls streaky after I washed off the construction dust?
Usually the dust was still on the wall when the water went on, so it turned into a thin paste, or the cloth was too wet. Buff the streaks with a dry microfibre cloth first. If they stay, wipe once with a cloth dampened in clean water and dry the strip with a towel straight away.
