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Should You Repair or Replace Your Historic Ornamental Plaster?

Deciding whether to replace, or restore historic ornamental plasterwork is a difficult decision; and not one to be taken lightly. Often, guardians of a historic property feel as if a bit of history and character is lost when replacing original plasterwork. But in order to maintain and ensure longevity, replacing plasterwork is a reality that often must be acted on. This difficult choice it is a two-fold decision that can be reached with the guidance of a plaster expert by; firstly, assessing what the condition of the ornamental plaster itself is, and secondly, assessing the condition of the visible flat plaster which the ornamental plaster sits on top of is. Understanding the condition and forces acting on these two surfaces will help you reach an informed decision. Additionally, scale of the project and budget often weigh heavily on the decision, too.

Cracking Plaster

Cracking Plaster

Assessing Condition of Ornamental Plaster

Well-executed ornamental plaster is the focal point of any space it adorns. Deep, richly-carved three-dimensional patterns and dramatic paint schemes, or glittering gilding, brings life and energy into a room. Overtime, however, exposure to frequent use, water damage, bad restoration, or poorly integrated modernizations can cause total or near-total destruction of original ornamental plasterwork. Identifying the type of damage is an important primary step:

Water Damage:

While often catastrophic in nature, water damage can be broken-down into two main varieties: acute and chronic. Plasterwork damaged by acute (single event) water exposure often has a better chance of being restored than plaster damaged by chronic (repeat/active) exposure. Acute damage is less likely to thoroughly soak through all the plaster layers, and usually will runoff of, or bead-up on painted surfaces. Chronic exposure can result in protective paint/varnish layers being deteriorated, and water soaking into the plaster layers. Similarly, water damage that occurs within the wall will result in water being soak through inner layers outward; similar principles apply. Once the event has ended, the plaster has dried, and the water problem rectified, identifying damaged or compromised areas and assessing the scope of damage will help determine if full replacement is necessary. Usually, acute damage results in small pockets that need to be replaced, which the bulk of the work being repairing the remaining plaster.


Plaster in heavily trafficked areas is prone to chipping. Touching chair rails, bumping into doorways, moving furniture, and overzealous cleaning will take their toll on a space over years and decades. Often, fixing chips and cracks caused by the aforementioned activities is simple and frequently done. Simple designs can be reshaped or carved, while more complex motifs might have to partially recast. Deep, or repousse-style patterns, might be too difficult to repair.

Removal Of A Section In A Larger Sequence:

When plaster is removed to allow ventilation or conduit piping to pass, replacing missing plaster maybe the only choice. In this case, determining the full repeat of the pattern and where a missing section falls on the full motif becomes essential. Simple repeating patterns, or standard decorative trim work, will prove easier to duplicate, whereas complex reliefs will often require historic research to complete.

Climate damage:

Hot, damp air can wreak havoc on historic plaster. Plaster swelling, softening, and deterioration can occur, depending on the original suitability and quality of the plaster mix. Climate control will usually solve this problem, and repair work to plaster can proceed without concern that the damage will reoccur.

Assessing Condition of Flat Plaster

Damage to the flat plaster at times can be more complex an issue than repairing or replacing ornamental plaster. Prior to repairing any ornamental plasterwork, it is important to conduct a complete review of the flat plaster it rests on; it is possible that the damage exhibited in ornamental plaster stems from damage to the flat plaster. As discussed in previous blogs, common damage to flat plaster includes; water, load displacement, lath movement, and improper application. Unfortunately, damage to flat plaster often results in ornamental plaster having to be removed and completely replaced. Prior to investing in repair or replacement, it is critical to receive professional consultation about the state of all plasterwork.

Plaster in need of Repair

Flat Decorative Painted Plaster, Cracking and Detached

Other Factors for Consideration


The scale and scope of work will inform whether replacing or repairing plaster work is the more appropriate, or feasible option. Spaces with large scale damage, or areas with different types of damage might lean towards complete replacement, while projects with smaller scales and similar damage might be candidates for repair. The longer a project is delayed, the greater the scale of the project usually increases. Differed maintenance is never desirable, but often is a function of budget.


Proper, historically accurate restorations and associated modernization are expensive undertakings. It is important to consult with your plaster restoration expert to identify all the options and compare costs and outcomes with them.

Simultaneous Improvements (lighting, electrical, HVAC, telecommunications):

It is always worth noting, if walls need to be opened it is a good time to review what systems should stay and which need to be upgraded.

Ornamental Plaster-Salvaging the Ornate Floral Scroll From

Deciding to repair or replace ornamental plasterwork is more complex than just surface appearance, it requires an understand of conditions that might not be visible on the plaster surface, understanding how a space has been used, is used, and might be used in the future will help inform a preservation committee or building guardian how to proceed with ornamental plaster restoration work. Making an informed decision means consulting experts and carefully weighing options. Regardless if you restore or replace, hiring an experienced team will ensure a beautiful, functional, and timely outcome.

Canning C

April 15, 2020

Featured Projects

DC Union Station

Washington DC’s Union Station

This project included the conservation and restoration of 40 Legionnaire statues in Washington DC’s Union Station by John Canning & Co.

Cosmos Club

John Canning & Co. scheduled all trades and performed specialty contracting to conserve and restore fine-art murals, ornamental plaster, gilding, decorative finishes and the parquet floor of the ornately decorated Cosmos Club ballroom in Washington, DC.

French Consulate, New York City Historic Decoration Projects

French Consulate, New York City

This elegant Fifth Avenue Italianate residence became home to the French Consulate in 1942. Great care has been taken to preserve the historic decoration and ornamental plaster details.


Shubert Theater

John Canning & Co. analyzed the Shubert’s historic paint and helped reattach its plaster and repair the theater from water damage.

John Canning & Co. Resources

As a conservation studio and restoration contractor, our team of highly skilled craftsmen, artisans, and conservators are experienced in the use of traditional methods and materials. We understand the importance in sharing our expertise and knowledge in our field.

Check Out Our Guide For Plaster Assessment