What You Need to Know About Plaster Crown Molding Repair
Plaster crown molding can add a great sense of elegance and style to your home, drawing the eyes up and adding height and grandeur to a room. Intricate designs in molding also provide depth and texture to a home’s walls and ceilings, adding historical charm to the space.
Repairing any plaster in a home is best left to a restoration professional, as sections of plaster may need to be fixed at the lath, or base that holds plaster in place. Recreating details in crown molding might also require a measure of artistry and skill. A professional repairperson can also address the cause of plaster damage so that the trim doesn’t continue to chip, crack, or fall away from its base.
Consider how plaster is repaired and how details in crown molding are recreated, to ensure you have any plaster pieces in your home properly fixed.
How is Plaster Made?
It’s vital that a homeowner understand how real plaster is formed, as you will then know why you want to avoid repairing it with putty, joint compound, and the like! Using materials that are meant to fill in drywall or wood trim will make for an unsightly match against your home’s current plaster details.
Real plaster is a mixture of gypsum or lime, sand, and water. Gypsum or lime, when mixed with water, create a type of cement, while sand keeps this material from becoming overly dense and hard. Plaster has been in use as a building material for hundreds of years and has been a favorite choice for decorating commercial buildings and homes, especially those constructed during the prewar era, in the Brooklyn area.
Benefits of Plaster
Plaster is still a popular choice for new construction, especially in tropical areas or cities near any significant water body. Note why that is and a few other benefits of genuine plaster for construction:
- Plaster has no biological materials that feed and encourage mold growth. Wood materials behind plaster can still develop mold, but unlike drywall and other such materials used to create walls and ceilings, plaster itself will not feed mold or allow it to spread.
- Plaster is very dense and durable, and less likely to crack or outright break than drywall.
- Before plaster sets and cures, it can be molded and cast into just about any shape. Along with details in crown moldings and medallions, plaster walls can also be finished with swirl patterns, textures, and a variety of other surfaces that cannot typically be formed on drywall.
How to Remove Plaster Crown Molding
If your home’s crown molding is severely damaged, and you want to attempt repairs on your own, you may need to remove sections of that plaster entirely. Removing plaster trim is not as easy as just pulling the plaster away from the wall, as you might do with wood trim. Consider a few necessary steps for removing plaster mouldings:
- Start by inserting a utility knife between the molding and the ceiling, and gently scoring through the paint or adhesive so that the trim then begins to separate from the ceiling.
- Use a mallet to tap a pry bar through the area of separation.
- Once you’ve created a gap between the molding and the ceiling, slide a shim into place. Work your way along the length of the molding and add more shims as you go.
- After adding enough shims, you should be able to pry the crown molding away from the wall without causing too much damage.
Once removed, you can then have the molding replaced or go without any trim of any sort. However, note that your property values and your home’s aesthetic value may be affected once you remove original plaster crown molding, so consider having it repaired when possible rather than discarding it.
How to Copy Plaster Mouldings
If your home’s crown moldings or other such pieces have decorative details, you’ll need to create plaster molds of that design for new plaster pieces. Start by cleaning the current, undamaged plaster with a release agent. This substance will remove dirt, dust, and other debris so that you can create a precise mold of its overall design.
If you search online for how to make a plaster mold, you might find suggestions that you use plaster of Paris or clay, and press this material into the undamaged plaster, replicating its detailing. However, an actual mold paste is the best choice for creating a cast of the decorative details in plaster. Mold paste hardens to a type of rubbery plastic that will allow you to easily create a new section of plaster with that same detailing. You can then use this new section to replace old, damaged areas of plaster crown molding.
Why Does Plaster Crack
Not all plaster damage should be addressed by a homeowner, as cracks in plaster can sometimes indicate severe structural damage to your home’s ceiling or even its foundation. This damage should be repaired along with the plaster, to ensure your home is safe and secure, and to stop that damage from getting worse over time.
- Hairline cracks in plaster may be somewhat normal, and the result of age, but long and wide cracks in walls and ceilings often indicate that the home’s foundation has settled and shifted. The foundation may then need patching or underpinning. Repairing and bracing up the foundation in this way will keep the home’s framework from cracking.
- Bubbling along the surface of plaster indicates that the home has a water leak, which can lead to dangerous mold growth. While plaster itself won’t feed mold, as said, other parts of the home’s framework may allow this mold to grow and spread; this water leak can also soften the home’s wood framework, leading to cracks and breaks.
- Delamination refers to sections of plaster that are starting to fall away from the lath keeping it in place. When plaster pulls away from its foundation, you might notice sagging parts of the ceiling or bulging areas along walls. If left unchecked, these sections of plaster can fall apart; because plaster is so dense and heavy, this can be dangerous to someone in the room!
Plaster Crown Molding, Repair or Replace?
While only you can determine the best choice for maintaining your home or commercial building, you might note some factors to keep in mind when it comes to deciding between repair or replacement of plaster crown molding. Be sure to discuss these options with a plaster repairperson or installer as needed.
- Genuine plaster is often appreciated for its historic charm and durability. Even if you were to replace damaged plaster with real plaster rather than wood trim or other such materials, your home’s value might be affected by the use of new gypsum versus aged or historical details.
- A plaster repairperson is skilled in plaster mold making and can often repair any damaged plaster, even very detailed crown moldings, cornices, medallions, and the like. Don’t assume that a damaged area is beyond fixing or that the repair work would be visible and then detract from a home’s overall appearance, but discuss your repair options with a professional as needed.
- Repaired plaster is often as strong as new. Fixing plaster won’t leave your home’s crown molding with weakened areas, and the damage is not likely to spread after a section of plaster has been patched.
- Plaster crown molding is very durable, as said. Wood trim will need repainting or fresh coats of stain over the years, to protect it from water damage and mold growth. Investing in plaster repair now, versus replacing that plaster with wood, can mean fewer repair bills over the years.
Why Call a Professional For Crown Molding Repair
Repairing crown molding involves more than just patching cracks and breaks in these features. Note why it’s good to leave this work to a professional versus trying to tackle it on your own:
- A professional plaster repairperson will know how to look for structural or water damage behind the plaster, and if the house itself is in need of repairs.
- A professional will also be able to properly examine the lath or base that holds plaster in place, and note if this part of the home’s framework needs repair or replacement. Applying new plaster to a broken lath can result in future cracks and breaks, so it’s vital that it be examined before repairing or adding new gypsum.
- Matching paint colors between repaired plaster sections and original plaster can be challenging, especially if that paint has yellowed or discolored with age. On the other hand, applying fresh paint to all the crown molding to match the color its can detract from the historic charm of this trim work. A plaster repairperson can match paint colors or know the right paints to choose that will retain the historical, aged look of original plaster.
A professional repairperson will ensure your home’s plaster crown molding is in good repair and also looks its best, preserving its historic charm and the overall condition and appearance of your house as well.