As an architectural metal, [cast iron] made possible bold new advances in architectural designs and building technology, while providing a richness in ornamentation. (John G. Waite, with Historical Overview by Margot Gayle, The Maintenance and Repair of Architectural Cast Iron, 27 Preservation Briefs, U.S. Department of the Interior, National Park Service & New York Landmarks Conservancy)
Previously, in the first of the series on preservation briefs, we focused on the maintenance of historic concrete. This week, we will take a look at the maintenance of architectural cast iron. Cast iron became cost effective with manufacturing techniques introduced in the Industrial Age, and its fire-resistance made it especially attractive in large urban areas.
The 19th century left us with a rich heritage of new building methods, especially construction on an altogether new scale that was made possible by the use of metals. Of these, cast iron was the pioneer, although its period of intensive use lasted but a half century. Now the surviving legacy of cast-iron architecture, much of which continues to be threatened, merits renewed appreciation and appropriate preservation and restoration treatments. (Waite & Gayle, 1991, p. 3)
Mississippi is home to a number of examples of iron store fronts, including those manufactured by Mesker Brothers, as well as other examples from Jones-McIlwain Iron Works in Holly Springs and Chickasaw Iron Works in Memphis. The c. 1855 Rumble & Wensel Warehouse, remodeled 1892-97, in historic downtown Natchez is an excellent example (MDAH, HRI database).
From Alcorn State, these stunning cast iron stairs are another fine example from HABS. According to the Mississippi Department of Archives and History, the steps were formerly from “Windsor,” of the Windsor Historic Ruins, whose Corinthian column capitals are cast iron and are currently undergoing stabilization.
One of the most splendid examples of cast iron in Mississippi is found inside the old Warren County Courthouse. You can see photographs of the staircase and judge’s dais along with a number of others at Going Inside: Old Warren County Courthouse.
Cast iron was considered structural as well as decorative. Building fronts, columns, domes and cupolas, and lightcourts and skylights were structural. Decorative cast iron included stairs, elevators, lintels, grilles, verandas, balconies, railings, fences, cresting, street furniture, lighting, fountains, statues, and tombs (Metals in America’s Historic Buildings, M. Gayle, D. W. Look, & J. G. Waite, 1992, National Park Service).
Two Oxford examples are included in the slide show below; admire a few other state examples before digging in to maintenance, repair and preservation of these important architectural examples.
Maintenance and repair must conform to local building codes, environmental protection, and be done by experienced and qualified workers using protective equipment, under the guidance of a preservation architect. In other words, “do not attempt this yourself”: It is a job meant for pros.
What are some of the tell-tale signs of deterioration?
- Rust, missing elements, damage, structural failure, broken joints, damaged connections, and loss of anchorage in masonry
As with many materials (concrete, masonry, wood for example), exposure to moisture is a factor, and particularly with corrosive agents: sea water, salt air, acids, acid precipitation. Architectural details that trap moisture also increase the speed of rusting, and rust on the surface furthers corrosion.
As with historic concrete, assessment and planning is an essential step in maintenance and repair. Understanding the condition of the iron requires a physical inspection of construction, bolts, fasteners, brackets, etc., and may require removal of a section of paint to appropriately determine the condition of these important elements. Load-bearing elements must be assessed. In Mississippi, support columns and beams are the most common cast iron elements that I have run across. While some are in good repair, others are in varying stages of neglect. Preservation and maintenance of those columns and beams is essential in order to ensure they are performing as designed: load-bearing support for the building.
Preservation includes a variety of tasks, including cleaning and paint removal, which can range from simple to complex, painting and coating, caulking, patching, and mechanical repairs, and only if absolutely necessary when features are missing or corroded or damaged beyond repair, duplication and replacement (Waite, 1991).
A successful maintenance program is the key to the long term preservation of architectural cast iron. Regular inspections and accurate record-keeping are essential.
For additional history and photographs about cast iron architecture, see:
- Mesker Brothers blog
- National Park Services Preservation Brief: The Maintenance and Repair of Architectural Cast Iron