Ceiling Leak or Sagging Ceiling, What to Do Right Now

Get Everyone Out From Under It

A ceiling that is dripping, stained or bulging is holding water above it, and water is heavy. One gallon weighs about 8.3 pounds, and a soaked patch of insulation can hold many gallons. Drywall loses strength as it gets wet, so a ceiling that looked fine an hour ago can drop without warning.

• Get people and pets out of the room right away.
• Close the door, and put something across it so no one walks in.
• Move furniture, electronics and valuables out only if you can do it without standing under the wet area.
• Cover what you cannot move with a plastic tarp.

Warning signs that a ceiling is close to failing include a bulge that is growing, cracks spreading from the wet area, drywall tape or seams pulling apart, screws or nails popping, and a sag deep enough to see easily from the doorway. If you see any of these, leave the room and call a pro.

Plaster ceilings, common in homes built before the 1950s, are much heavier than drywall. Wet plaster can let go in large chunks from the wood lath above it. Treat any wet plaster ceiling as dangerous.

Cut Power to Wet Fixtures

Water finds its way to ceiling light boxes, fans and hardwired smoke alarms because those are holes in the ceiling. Water in an electrical box is a shock and fire risk.

• Do not flip the wall switch for a light or fan that has water in it or near it.
• Go to the breaker panel. If you can reach it standing on a dry floor with dry hands, turn off the breaker for that room. If you are not sure which breaker it is, turn off the main breaker.
• If the panel is wet or in a wet area, do not touch it. Call your electric utility or an electrician.

Hardwired smoke alarms can chirp or go off when water reaches them. Turning off their circuit silences them, so put in a battery smoke alarm in the meantime and keep your carbon monoxide alarms working.

Leave the power off to that area until the fixtures and boxes are completely dry and an electrician has checked any that held water. Lights and fans that were full of water often need replacing.

Draining a Bulging Ceiling Safely

If the ceiling has a small, stable bulge of water, draining it in a controlled way can stop it from tearing open and spreading water across the room. Do this only if the bulge is not growing fast, not cracking, and the ceiling is drywall rather than plaster.

1. Make sure power to the room is off.
2. Lay a tarp on the floor and set a bucket or large tub directly under the lowest point of the bulge.
3. Put on safety glasses. Stand on a stepladder to the side of the bulge, never directly under it.
4. Push a screwdriver or awl through the ceiling at the lowest point to make a small hole. Water will run out.
5. If the water flow slows, make the hole a little bigger, but keep it small.
6. Step away and let it drain. Empty the bucket before it fills.

A textured or popcorn ceiling in a home built before the mid 1980s may contain asbestos. A single small drain hole is a much smaller disturbance than a collapse, but do not scrape, sand or break off pieces. Wet wipe any debris, and have the texture tested before any repair.

If the bulge is large, the ceiling is plaster, or you feel unsure, do not puncture it. Leave the room and call a pro.

Find and Stop the Source

Draining the ceiling buys time. Stopping the source ends the problem. Think about what is above the wet spot.

If you have water on a ceiling and no idea why, shut the main water valve. If the dripping stops within an hour or so, the source is plumbing. If it keeps going and it is raining, suspect the roof. The hidden leaks guide has more ways to narrow it down.

Check What Is Wet Above the Ceiling

A wet ceiling is usually the bottom layer of a bigger problem. Before you decide anything about drying, find out what is above it.

If there is an attic above, go up with a flashlight, stepping only on joists or plywood walkways. Look for wet or matted insulation, water stains on the wood, and the source. Blown in insulation soaks up water, gets heavy, and presses down on the wet drywall. Soaked insulation needs to be removed and replaced.

If there is a floor above, the space between floors holds joists, pipes and sometimes insulation. Water can travel several feet along joists before it drips, so the wet spot on the ceiling may not be under the leak. You often cannot see into this space without opening the ceiling.

Use a moisture meter to map the wet area on the ceiling from below. Stand on a ladder to the side and scan outward from the stain until readings match a dry part of the ceiling. The wet area is usually bigger than the stain.

Photograph the ceiling, the stain, the attic and any source you find. Call your insurer, and in a building with other units, notify the owner or manager in writing.

Can the Ceiling Be Saved

Some wet ceilings can be dried in place. Many cannot.

Drywall that has sagged will not go back flat. Once it bows, the gypsum has lost its strength and it needs to be replaced. The repair usually means cutting out the wet area back to the nearest joists, drying the framing, replacing the insulation, then hanging and finishing new drywall.

To dry a ceiling in place, remove the wet insulation above it if there is attic access, run a dehumidifier in the room, and point a fan up at the ceiling. Most small clean water stains dry in 2 to 4 days.

Stains, Paint and Leaks That Come Back

Once the ceiling is truly dry, a water stain can be covered, but plain ceiling paint alone will not do it. The brown ring bleeds through.

1. Confirm with a moisture meter that the stained area reads the same as a dry part of the ceiling.
2. Clean the stain lightly with a damp sponge.
3. Apply a stain blocking primer made for water stains.
4. Paint with ceiling paint once the primer has cured.

If a stain comes back after it was primed and painted, the leak is still active or the area was not dry. Do not keep painting. Find the source.

Watch for mold after any ceiling leak, especially where insulation was wet. Dark spots on the ceiling, or a musty smell in the room or the attic, mean mold may be growing. Small areas under about 10 square feet can often be cleaned by a homeowner. Larger areas, or mold in an attic over a large ceiling area, call for a mold professional.

If the leak came from an attic air conditioner, ask an HVAC technician about a float switch that shuts the unit off when the drain pan fills. It is an inexpensive part that prevents the next ceiling leak.

Step by Step

1. Clear the Room

   Get people and pets out from under the wet ceiling and close the door. Move belongings only if you can avoid standing under the wet area.

2. Turn Off Power

   Turn off the breaker for any wet light, fan or alarm from a dry spot. Never use the wall switch.

3. Catch the Water

   Lay a tarp and set buckets under drips. Cover furniture you cannot move.

4. Drain a Small Bulge

   If a drywall bulge is small and stable, stand to the side and make a small hole at the lowest point with a screwdriver so it drains into a bucket.

5. Stop the Source

   Close fixture valves above, turn off an attic AC unit, or shut the main water. In an apartment, call the super or the neighbor above.

6. Check Above

   From the attic, look for wet insulation and the source, stepping only on joists. Photograph everything.

7. Map the Wet Area

   Scan the ceiling with a moisture meter out from the stain until readings match a dry area.

8. Dry or Remove

   Dry a firm, flat ceiling with a dehumidifier and fan. Have sagging or soft drywall and wet insulation removed and replaced.

Mistakes That Make It Worse

• Standing under a bulging ceiling to poke it. When it lets go, all the water and drywall come down on you.
• Flipping the switch for a light that has water in it. It can short, shock or start a fire.
• Painting over a ceiling stain before it is dry. The stain bleeds back and moisture stays trapped.
• Leaving wet insulation in the attic on top of a dried ceiling. It keeps the drywall wet and grows mold.
• Assuming the leak is right above the stain. Water travels along joists and pipes before it drips.

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