What the bulge is telling you
- Soft, damp or stained. Water. The gypsum core has absorbed it and is losing strength.
- A hard ridge along a seam. The tape joint has lifted or was over-filled. Cosmetic.
- A small, round bump. A nail or screw pop. Cosmetic; see drywall crack repair.
- A long, gentle bow. A warped or twisted stud behind the board. The fix is at the framing.
- A sagging ceiling. Water weight or fasteners too far apart; see drywall ceiling repair.
If it is wet: what to do right now
- Find and stop the water. Look above and behind: pipes, a toilet or shower on the other side of the wall, a window, the roof. Shut off the water supply if it is a pipe.
- If the bulge is near outlets, switches or light fixtures, switch off the power to that circuit.
- For a ceiling holding water, put a bucket underneath and keep people out from under it. It can come down without warning.
- Photograph everything before any cleanup, for your insurer.
- Start drying: fans, a dehumidifier, and remove wet baseboards so air can reach the wall.
Can it be saved, or does it come out?
Drywall that got briefly wet from clean water and dries quickly, staying firm and flat, can sometimes be primed with a stain-blocking primer and painted. Board that is soft, crumbling, sagging, stained through, or smells musty needs to be cut out and replaced, along with any wet insulation behind it. A moisture meter takes the guesswork out: drywall can feel dry on the surface and still be wet inside.
How the repair is done
- Cut out the damaged section, usually to at least a foot beyond the visible damage and back to the nearest studs.
- Check the cavity for mould, wet insulation and damaged framing, and let it dry completely.
- Replace insulation, screw in new drywall, then tape and finish in thin coats.
- Match the texture, prime with a stain-blocking primer, and paint.
What it costs
| Job | Typical cost |
|---|---|
| Water-damaged section, Metro Vancouver Cut out, dried, replaced and finished | $300–$650 |
| Typical drywall repair job | $150–$600 |
| Larger or spreading damage Scope is set once the wall is opened | Quoted after inspection |
Sudden leaks, such as a burst pipe, are often covered by home insurance; slow leaks that happened over months usually are not. Check your policy before repairs start, and keep the photos.
Leaks in strata buildings
In a condo or townhouse, water coming from another unit, the roof or a common pipe may be the strata corporation's responsibility. Report it to your strata manager right away, keep photos, and settle who is responsible before repairs start. Insurance deductibles and your strata bylaws decide who pays.
Common questions
Is bulging drywall dangerous?
On a wall it is usually more a sign of a problem than a hazard. On a ceiling, a bulge full of water can fall. In both cases, find the water source fast.
Can wet drywall be dried instead of replaced?
Sometimes, if it got wet from clean water, dries within a day or two, and stays firm and flat. Soft, sagging or stained-through board should be replaced.
How do I know if the wall is still wet inside?
A moisture meter is the reliable way. Surface dryness is not enough, because the core and the cavity behind it hold water for much longer.
Related guides
Compiled from published 2026 Metro Vancouver cost data (local drywall contractor pricing guides), in CAD. Mould timing from Health Canada guidance on moisture and mould. We update these figures as we complete jobs.