In a current architectural craze of sustainable measures and repurposing structures, it makes sense that the proper treatment of historical buildings has become more of a focal point. The concept of reusing aspects of buildings is simple — recycling materials is more eco-friendly than new construction that burns through countless hours of machinery to create new products.
With that in mind, we turned our attention to metalwork, and the role it plays in repurposing historic works. While you can use this information as a guide to your own DIY projects, the federal government has written standards when it comes to dedicated historic properties.
As part of the National Historic Preservation Act (NHPA), the United States Department of the Interior formulated an in-depth document called the Standards for the Treatment of Historic Properties. These guidelines cover four sections: preservation, rehabilitation, restoration and reconstruction. Restoration and reconstruction are more invasive, while preservation and rehabilitation focus more on maintenance and protection.
The standards and recommendations canvas a broad spectrum, from types of materials to safety measures and special instructions to consider. For this exercise, we’ll zero in on the role metalwork has played in architecture and how we can help preserve its relevance in historic buildings.
Types of metal used in historic architecture
You’ll find nearly a dozen types of metals associated with historic architecture, ranging from copper and bronze to aluminum and stainless steel.
For starters, you’re likely familiar with wrought iron for its usage in fences and railings. This use of iron became more prominent in the 19th century with columns, structures and other interior designs. Today, we know cast iron for its role in cookware like skillets and dutch ovens. Warehouse and industrial buildings began displaying cast iron columns in the 1800s.
As we outlined in this blog post on metalwork in the 1930s, steel was a common use for skyscrapers and other notable buildings. Stainless steel picked up steam in the 1920s as a notable fixture in Art Deco-style buildings.
Architects used lead, combined with a tin coating, as a roofing material in historic buildings. It was later mixed with zinc to add custom finishes to roofs. Prior to that, buildings used copper for roofs. Bronze and brass, two offsprings of copper, helped add finishing touches to buildings. These metals contain few traces of iron and are ideal for exterior projects since they share corrosion-resistant properties. Eventually, these metals became components of interior design, whether as kitchen fixtures or knob handles.
Aluminium became more popular for exterior uses, especially siding, thanks to weather-resistant properties. Architects used aluminium siding in the 1920s and 1930s as part of the Art Deco movement before it became a more common household item in the 1940s after World War II.
Historic preservation of metalwork
The focus here is on sustaining, maintaining and protecting the original metalwork. Ideally, you achieve this through existing metalwork instead of introducing new materials. You can use repairs or limited replacement as long as they feature the same design, color and texture of the original metalwork.
You shouldn’t alter or outright replace metals, as this will diminish the character. Instead, fix any issues with repairs. The only additions that apply come outside of metalwork. For example, when preserving a building, you can perform electrical and plumbing work to keep the building up to code (or to make it more energy efficient).
Stabilization is key before you begin a project. Some metals can deteriorate or react differently as part of the preservation process. As part of the protection (maintenance) step, it’s important to treat metals with care prior to any repairs. This helps you avoid any further damage. An easy solution is to fix leaky roofs and ensure areas have proper drainage. Any unwanted moisture can cause corrosion in metals.
Clean soft metals (lead, copper and zinc) with non-corrosive chemicals to preserve their integrity. You can use minimally invasive abrasives for sturdier metals like cast iron and steel. Once treated, it may be beneficial to introduce a protective coating to prevent further erosion and deterioration.
In this stage, you should only carefully consider replacing metals after you protect, stabilize and repair. Additionally, you should establish surviving prototypes or physical evidence before replacement metals. Ideally, the new project will be an exact copy of the old work, all the way down to the design, color and finish.
Historic rehabilitation of metalwork
Many of the same concepts and precautions of preservation apply to rehabilitation, although you have more leeway. You want to prioritize protecting and maintaining metalwork. Try repairing metals instead of outright replacing them. But, in the event you need to replace something, rehabilitation guidelines allow you to construct a new addition. For example, you can replace a disheveled, leaky roof as long as the character and historical appearance goes unchanged.
Protection is key here, especially since rehabilitating historic buildings generally requires the most work of the four. You can use historic documentation to replace metal structures when they become too rundown. It’s safe to use alternative metals if the existing metal isn’t feasible.
You can implement a new design as long as it meshes with the size, scale, material and color of the historic building. Even with the leeway and flexibility, you still need to account for design compatibility and the way in which the metalwork coexists with other features on the building.
Historic restoration of metalwork
Using this method, you bring back to life metals of a certain time period. Instead of replacing items, you should first attempt to repair metal features. In some cases, metalwork from a particular era may be too deteriorated to repair. When this occurs, you can replace metals so they resemble that period or you can match them with a comparable material to that of the original. It’s important to remove features from other periods that could cause confusion and avoid replacing metals with other materials that don’t match that particular era.
Whereas other historic methods shy away from recreating features or objects, this is a popular option when using historic restoration. You can add to a building by creating a feature that was present during that particular era. This doesn’t apply to metalwork that was part of the original design but was never physically constructed.
Historic reconstruction of metalwork
If a historic building's metalwork no longer exists and you need to rebuild, use reconstruction — though this is the least popular method of maintaining historic buildings. You need detailed documentation for a reconstruction, which makes it difficult to pull off, since many buildings lack physical evidence to base such a large undertaking on.
Metalwork reconstruction is rarely carried out in totality. In other words, you wouldn’t reconstruct an entire building with key metalwork features. Instead, you could justify, with proper documentation, reconstructing parts of the exterior, while the interior isn’t modeled after any historic significance.
You can use substitute materials if the general appearance stays the same. Interior fixtures should remain intact. That means reconstruction of brass or bronze fixtures should match historical appearance in design color and texture.
Using Coco for your renovation project
Whether you’re replacing elements of a room or you’re looking to add features to an existing design, we have several ways to implement metal grilles into your historic projects.
This is a popular use for historic renovation projects, as it displays Gothic architecture of the High and Late Middle Ages. This pattern presents 56% free air as part of the ventilation.
We use this for contemporary builds and historic renovation projects. The pattern is available in three standard sizes with differing free air percentages ranging from 39 to 5%.
The Art Deco movement in the 1920s featured design like this majestic grille. The pattern is available in three sizes with air percentages ranging from 54 to 6%.
While we use this for commercial and high-end residential projects, this blends well with historic projects. It comes in three sizes with free air percentages ranging from 20 to 35%.
This popular square design is uniform yet versatile. It comes in three sizes and free air percentages range from 25 to 64%.
Contact us today if you’re feeling inspired to start a custom metal grille project of your own. We offer linear bar grilles, perforated metal grilles or custom metal products, and we’re eager to help you find the perfect solution for your project. Download our product catalog or request a quote for more information.