Metal windows can be beautiful and are an integral part of many old buildings. If well maintained and properly treated, metal windows can last for a very long time. But rust and corrosion damage metal windows over time if not checked.
The original historic metal windows bring character and aesthetics to the building and should never be replaced by plastic or other alternatives. If repair is possible, this should be done with traditionally manufactured glass. It is of great importance that existing old windows are maintained when possible and used for repairs and reconstruction work.
Whether the original windows were made from wrought iron, cast iron or steel, a maintenance routine should be developed to ensure that the windows last as long as they should.
Removing several layers of old paint from a metal window can help to increase its functionality, but caution is required if there is a risk of lead paint applied to the window in the past.
Dealing With Rust
If the windows are rusty or corroded, have the affected window parts cut out by a professional. A new replacement section can be welded in position. However, cast iron is almost impossible to weld and can require cold metal seams done by professionals.
While slight corrosion can be removed by hand, heavy rust may require the use of acid stains or shot blasting, as well as the removal of the metal frame from its location.
Metal framed windows can be extremely draughty if they no longer fit well. And the will require professional restoration. The old glazing will often have to be removed from the metal frames
Where a metal frame needs attention, the straightening of dents and the removal of glaze or old putty is a typical repair technique that used.
Restoration or Replacement?
All new windows in a house must comply with building regulations, but for historic or heritage buildings where full compliance changes the character, there are important exceptions and special considerations.
The restoration technique used often depends on the budget and the historical context of the window.
Where existing windows are no longer repairable, having a new residential window replacement in an old building can be justified by the heat radiation from the glazing. However, if there is no reason to replace the window, then full or partial restoration is an option.
You can still find manufacturers of metal windows in the UK today. For example, Crittall Windows Ltd. dates back to 1849 and was an innovator of the process used to produce cheap steel windows in the 1850s that became a commercially viable product for mass production. And the company still manufactures Crittall replacement window units today.
Investing In The Future
Once restored, metal sash windows can last longer than a new PVC replacement window would. With proper maintenance and care, restored or replacement metal windows often remain in excellent shape for many more years to come. They undoubtedly add character and elegance to any property where they are installed and they should be cherished for the architectural heritage they represent.