Paint has been with us since prehistoric times. Some of the earliest existing forms of paints were created from mixing organic materials, dirt, and ash with animal blood and oil. While painting the exterior of different structures has been around for quite a long time, but not everyone used to paint the exterior of their homes. E.g., early settlers in America declared the act of painting the exterior of houses as a sign of wealth, immodestly, and vanity. Well, in some community painting, the exterior might have landed the owner in some form of legal trouble.
For farmers and their barns in some regions, the mentality was the same. A painted barn was known as a symbol of wealth, and since the only reason to paint barn was just to add color to the barn or structure. Well, farmers didn’t find any logic in spending money to make their barns look pretty.
Now, you might be thinking of how people preserve the wood of their homes and other building without sealants? Before the 19th century, many farmers believed in the philosophy, i.e., The right wood in the right place doesn’t need paint.
How did barns get the traditional red paint?
As the years passed, farmers started to look for a longer-lasting solution to protect their barns from different elements. Different homemade solutions towards this end were made, the most popular base used by farmers was linseed oil. To strengthen the oil and help it dry quickly, farmers started to mix it with milk and turpentine or lime, and this led to the creation of something burnt orange color paint.
Though this mixture sealed the wood from moisture, it never stopped the growth of moss and mold that plagued wooden structures. To find a solution for this, farmers started to add iron oxide or commonly known as rust. Rust was easily found in the soils on eastern US farms, and many other places, which made it cheap and readily available. Adding iron oxide changed the color of the wood from burnt orange to dark red-brown color.
When the paint became cheaply available in the US because of mass production in the 19th century, farmers often bought the color red for their barns because the red color was generally the cheapest color available at that time. Thanks to the easy availability of iron oxide.
As for why barns are still painted with red color they know barns are of more bright red color rather than the classic red-brown color, its just because of tradition. There’s no particular behind this.
So our ancestors have painted their barns in red color because the red color paint was the cheapest one found in the market at that time. And we now just follow this tradition, there’s no such particular reason to paint barns red, it’s just tradition.