Avoid These Mistakes For Plaster Ceiling Repair

Proper, timely plaster ceiling repair ensures that your home's stucco is always in good condition and as attractive as the day it was installed and protects your home from potential water leaks and other such damage. A homeowner can typically repair minor cracks in plaster on their own, while a plaster restoration expert should address significant breaks, sagging plaster, and other such imperfections.

Avoid these common mistakes when attempting plaster ceiling repair:

• Always first correct the issue that caused sagging plaster, such as water leaks.
• Soft and crumbly plaster cannot be pushed back into place but needs replacing.
• Improper removal of damaged plaster can cause other areas of stucco to come down.

To ensure you keep your home's valuable plaster in good repair and don't cause any additional damage when trying to restore or repair plaster ceilings and walls, note some further mistakes to avoid during the repair process, and some tips on fixing and maintaining plaster in your home or office. Remember to call an expert when you’re not sure how to fix a plaster ceiling, so your home always looks its best.

Before Plaster Ceiling Crack Repair

A sagging plaster ceiling typically indicates damage behind the plaster, at the base of the roof itself. Water leaks will cause the wood of the lath that holds plaster to become soft and then cup and bow, allowing the plaster to sag. Broken lath and other such damage also allow plaster sections to pull away from the ceiling. Repairing sagging plaster and performing other plaster ceiling crack repair before determining the reason for it to sag, and fixing that damage will only result in more broken stucco.

Note, too, that plaster itself does not feed mold as it has no biological materials that allow mold to grow and spread. However, if a water leak in the home has damaged the wood lath behind plaster so that it starts to sag, that water leak can also lead to mold growth along the home's wall studs, drywall, and other such materials. Plumbing leaks also waste water and raise your utility bills!

Plaster ceilings can also begin to sag as a house settles and shifts over time. While settling is not necessarily unusual, once the home has shifted so much that it needs plaster ceiling crack repair, the home is probably damaged in other areas as well. A sagging plaster ceiling might indicate that it's time to check the home's foundation, roof, and subfloor for cracks, for example. For all these reasons, it's good to ensure you have the cause of sagging plaster identified and addressed before you repair the plaster itself.

Applying Adhesive to Fix a Sagging Plaster Ceiling

One quick fix for a sagging plaster ceiling is the application of an adhesive between the plaster and its supportive lath. Note the steps involved in applying adhesive behind broken ceiling plaster and how to repair a plaster ceiling:

• Feel the plaster with a flat palm, pushing it gently backward. You can then note if areas around the sagging section are somewhat loose, and also need adhesive.
• Use a commercial-quality vacuum and remove any dust and other such debris around the sagging plaster. Never try to vacuum loose and crumbly plaster itself, as this can pull entire sections of plaster away from the ceiling and can cause more damage. If the plaster is loose and begins to fall apart as you vacuum, it's good to call a plaster restoration expert for repairs.
• For damaged areas of plaster that need removal, use a sharp utility knife to score around the edges of that section, so that the plaster comes out cleanly and without pulling or damaging surrounding parts.
• Drill holes into the damaged plaster; these holes create injection points for the adhesive. These holes should also be drilled directly below sections of the wood lath behind it, not between those sections, as you want the adhesive to stick to those wood pieces rather than slide between them!
• Injection holes should be spaced no more than six inches apart.
• Vacuum any debris out of the injection holes and ensure they're clean and clear of dust, plaster bits, and so on. Vacuuming the injection holes also allows you to ensure you've drilled under the wood lath slats and not between them.
• Spray the injection holes with water, using any household squirt bottle, to dampen the plaster. Damp plaster allows adhesive to form a tight, secure bond.
• Inject liquid nails or another such construction adhesive into the injection holes, and gently push the plaster sections into place with a flat palm. Hold for several minutes, until the adhesive begins to dry.

Tips for Repairing Small Cracks in Plaster

To repair small cracks in plaster ceilings and walls that have not separated from the wood lath behind that damaged area, fill the break with a joint compound or other filler. Note some tips for how to repair plaster ceiling hairline cracks and other minor damage in plaster walls and ceilings:

• Start by widening the crack to at least 1/8", so that there is room to apply the filler. You can enlarge cracked plaster by gently tapping a putty knife into the gap, using a mallet or hammer. Use very gentle motions, so you only widen the hole and don't cause further cracks in the stucco.
• Use a heavy-duty vacuum to clean out plaster dust and other debris.
• Wash out the crack with water and a non-phosphate detergent, available at most hardware and home improvement stores.
• Use fiberglass mesh tape, also available at hardware stores, and cut a piece to fit over the cracked plaster. Use a sponge dipped in water to dampen the tape.
• Apply joint compound over the mesh tape, using a putty knife to smooth out the surface until it's even with the existing plaster. Allow this layer to dry thoroughly, even overnight if needed.
• Continue to add layers, as needed, until you can smoothly "feather" the edges of the joint compound across the existing plaster around the crack.
• Once the patched area is dried completely, sand it smooth. Apply a layer of latex primer and then paint the repaired plaster as needed.

For more extensive cracks in plaster, follow these same steps, but use actual patching plaster rather than joint compound. Ensure you follow the directions for the material you use and allow it sufficient drying time. Be sure to sand the fresh plaster to a smooth finish before applying primer and paint.

Repairing Holes In Plaster

Before filling holes in a plaster wall or ceiling, note if the wood lath behind the plaster is intact. If so, mix joint compound with plaster of Paris and inject this mixture into the holes, just as you would when fixing sagging sections of a plaster ceiling. If the lath is not intact you'll need to create a firm base to hold your repair compound:

• Use a chisel to cut away plaster surrounding the hole until you see secure sections of lath around the damaged area.
• Cut a piece of wire mesh with tin snips, and push this into the damaged area of plaster until it touches the intact sections of lath behind the plaster. The wire mesh should bunch up and fill the hole; this will create a stable foundation for your filler.
• Ensure you brush away all loose plaster and dust before applying your patching compound.
• Apply the compound in thin layers, and allow each layer to dry thoroughly before applying the next. This process ensures the plaster compound cures entirely and adheres appropriately to the existing stucco.
• Once the hole is repaired completely, snip away any exposed bits of wire mesh. Sand the fixed area, apply a primer and then paint.
• For larger holes in more visible areas of the home, you might use joint compound for the last layer of patching. A smooth finish is often easier to achieve with joint compound, and especially for homeowners not accustomed to applying actual plaster!

When to Call an Expert for Plaster Repair

While homeowners can often repair minor cracks and other such damage in plaster on their own, it's good to know when to call an expert for plaster repair. If a large section of plaster is sagging, call a plaster contractor for repairs. When a large part of plaster has pulled away from the wood lath behind it, the weight of that stucco can cause it to come crashing down during repair work.

Plaster repair experts can also recreate the details of decorative plaster pieces, including crown plaster mouldings, medallions, and the like. Don't assume you can just carve a decoration into a repaired area of plaster, as recreating these details takes quite a bit of experience and skill. Restoration experts also typically make molds or casts of these details for an exact copy. To ensure your home's valuable plaster detailing is preserved, call a restoration expert when those decorative sections or pieces require repair.

Related Questions:

Can you paint over damaged plaster?

Painting over repaired plaster can hide filler materials and patching compounds, but the paint itself is not meant to mask damaged plaster. Note, too, that it can be challenging to match aged colors on walls and ceilings. A plaster repair expert can find the best paints to use for an even finish.

Should you replace plaster with drywall?

While drywall is often easier to repair when needed, plaster is much stronger than drywall and doesn't feed mold growth. In some cases, plaster can even add to the value of your house, especially if the plaster includes detailed crown plaster moldings, medallions, and the like.

How long does it take to repair a plaster ceiling?

Note that plaster is not simply nailed to wood studs, but is built up or applied layer by layer. Plaster ceiling repair can then take several days, depending on the extent of damage, as a repairperson adds those layers individually.