Water can be a serious threat to your home because it can find its way through any material. You can be sure that water is leaking into your home if you notice a strange discoloration or, worse, sagging ceilings. The sooner you act, the better your chances of preventing further damage to your furniture or property. Your ceiling will only deteriorate with time, so it is important to identify where the water is coming from so it can be repaired as soon as possible.

Whether the damp ceiling is caused by a burst pipe, hole in your roof, or even a bath overflowing, a leaking ceiling is a serious issue, and you need to act right away to prevent further damage. Remove your belongings to avoid as much damage as possible. Assess the damage and prepare the area for repair.

You should remember that plaster is a hard and durable material, but it crumbles when it gets wet. The process of repairing a plaster ceiling can be a bit more complicated than fixing a drywall ceiling. Plaster is held in place by wood lath, which is thin strips of wood backed by plaster. You can attach drywall patches to these if necessary. You can fix plaster fairly easily using drywall and joint compound, but you should allow yourself three days for the project.

Getting started

It might be helpful to have the following already on hand before you begin

  • Putty knife.
  • Ladder.
  • Paint and brushes.
  • Primer.
  • Joint compound.
  • Mud pan.
  • Sanding block.
  • Clean cloth, and most importantly.
  • Protective glasses.

Now that you have the tools in place here is your step-by-step guide on what you need to do.

Take Out the Damaged Plaster

It is imperative to locate and stop the source of the leak before beginning any repairs to walls or ceilings that have been damaged by water. Otherwise, you will be repairing the same damage again very soon. In addition, be sure the plaster has had time to fully dry out before attempting any repairs.

In order to carry out repairs, the damaged material must first be removed. This includes peeling and bubbling paint, crumbling plaster finishes, and degraded lath. Then, remove the flaking paint and bubbled plaster using a putty knife. Make sure that you dig out all the soft, loose material with the blade.

Using the knife, dig around the damaged edges until you reach hard, undamaged plaster. To determine if the paint coat around the area can be peeled off easily, test the surrounding area immediately. To remove any damage, start with the center of the damage and work your way outwards.

Seal Any Water Damage

Remove any loose particles by brushing the surface with a stiff nylon brush and vacuuming. The surrounding surfaces should be cleaned with a sponge and bucket of clean water to remove any remaining lime deposits and the wall should be allowed to dry completely before continuing.

Once the surface is clean and dry, seal it with either an oil-based primer sealer or a quick-dry primer sealer. In order to block any residual contamination, priming must be performed, as it inhibits the bond between the patching compound and the surface. Moreover, it will prevent stains from bleeding through the topcoat, preventing bubbles from appearing in the fresh paint coat.

If the primer is not completely mixed, stir or shake the can on a continuous basis. Spread the primer on all the affected surfaces and overlap it onto the adjacent surfaces. Allow the primer to dry completely before applying the repair material. A quick-dry primer will dry in an hour while an oil painting may take twenty-four hours to dry completely.

Repair the Plaster

Use joint compound to fill in the plaster gaps and level out shallow surface damage. Apply a small amount of compound with a flexible joint knife. Using parallel strokes, apply a thick coat of mud to the area and then immediately go back over it to skim off the excess.

To fill in deeper damage, move the blade across the deepest part of it and skim harder on the surrounding walls. Make sure that the mud does not build up higher over the repair area than it does on the surrounding surfaces. To avoid unnecessary sanding, avoid leaving a thick layer of mud around the perimeter when you are done.

You can repair a large area at once by using a long, thin board such as lattice molding. To smooth out the high points in the overall repair, rest the board on the surrounding surface and drag it across the wet mud a few times. If the mud surface is inconsistent or has ridges, do not worry about it. Afterward, you can scrape them off before applying another coat of mud.

Once the joint compound has hardened, use a joint knife to remove any ridges or other roughness that may have formed. If necessary, use sandpaper to remove any other bumps. Just smooth out any high spots if necessary. Using a damp rag or sponge, remove the scraping and sanding dust before applying mud again.

Add a Second Coat of Joint Compound

As before, butter the surface with another thick coat of mud. Fill in the deepest part of the damage and keep the edges lighter.

Once you have removed the excess mud, continue in a perpendicular direction to the first coat to skim off more mud. The mud should be left as thin as possible on the surface of the wall to minimize sanding. Ignore any ridges left by the knife blade.

Afterward, sand, scrape, and wipe off the dust as before. Apply as many additional coats as necessary until the plaster is filled in. Maintain a level of repair by avoiding a buildup of mud on the surrounding surface. Also, reverse the direction of the coats after each new coat.

Sand and Touch Up Paint

After the last coat of joint compound has dried completely, sand the whole patch with 120 sandpaper. Ensure that the outer edges of the patch are merged with the surrounding wall surface. Use the same primer-sealer you used before to prime the new repair and surrounding surfaces after wiping off the sanding dust.

It is essential to apply a solvent-based primer-sealer in place of latex paint here to prevent residual water contamination from hindering the bonding of the new paint. Latex is suitable for use over primer, but it may bubble if applied directly over water damage. Wait until the primer has completely dried before touching up or applying the finish.