How to Repair Ceiling Cracks and Stains

Small cracks and dents in plaster ceilings can be fixed quickly with joint compound or spackle, which can be used for wallboard. If there are quite a few hairline cracks then these need to be covered with lining or a spun fiberglass wall covering.

Joint compound comes in various sized tubs, which are ready-to-use. For larger jobs, the 5-gallon sizes are economical. Spackle has the same qualities of joint compound but is more appropriate for walls because of its smoothness. This makes it easier to paint after your repair work is finished. Spackle comes in small containers and in squeeze tubes.

You will need the following materials to repair cracks:

Pointed filling knife

Old paint brush

Flexible putty knife

Sanding block

Fine wet or dry sandpaper

Joint compound or spackle

Caulking gun

Caulking compound that can be painted

Use the pointed filling knife’s edge to undercut the crack in your ceiling. You may also use the corner of a flexible putty knife for this. Undercutting the ceiling crack widens the crack below the surface, which forms an inverted ‘V’ hole, with the V’s point exposed to the surface. This helps the filler stay in position.

Now remove any loose fragments from the area that you are working by lightly brushing with an old paintbrush. Use the flexible putty knife to firmly press the compound or spackling into the crack. This will force it into the cavity.

Then hold the putty knife at an angle perpendicular to the area that you are working and scrape away the excess. But leave the excess filler slightly protruding from the surface. The more experienced person will be able to smooth the filler level with the surface. Let the filler dry.

After the filler has dried, wrap a piece of fine wet-or-dry sandpaper around a wood or cork sanding block. Hold it flat against the area and sand the filler until it is flush with the surface.

MORE DIFFICULT CRACKS

Not all cracks can be filled in this way. Normal shifting of a house can cause cracks at the joints. Filling them with the spackle or compound would just result in additional cracks later on. If these more difficult cracks appear where the joints meet the ceilings, the best solution is to hide them by attaching crown molding. However, cracks above baseboards or around window and doorframes will need a different method of repair. The best method is to use a caulking compound. This will remain flexible so the gap will stay closed despite any future house movements.

Squeeze a bead of caulking compound along the crack. Make certain that it contacts both surfaces. A slow, continuous movement will avoid any ripples. You can wet your fingertip to smooth down the compound.

STAINS

The majority of ceiling stains are due to either water damage or tobacco smoke. Stains will soak through paint but you can prime water stains. For tobacco smoke stains, first try a strong determent or trisodium phosphate (TSP) on the painted surfaces. If this doesn’t work, you will have to remove the paint. Wallpaper, also, will have to be stripped.

These are the materials that you will need to treat ceilings with water stains:

Small paint brush

Shellac-based primer

First, you must deal with the problem that caused the water stain, such as a plumbing leak. Allow the ceiling to dry before you begin to repair this problem. Then, you may apply a coat of shellac-based stain killing primer over a water stain. White is the most often available. The primer will seal the surface and form a good foundation to paint.