There are many theories that explain why barns are red. Hundreds of years ago when European farmers painted their barns, they often used linseed oil.
Linseed oil comes from the seed of the flax plant and the farmers would add lime or milk to the mixture to paint their barns. The combination of this linseed oil mixture resulted in a long lasting paint finish that hardened and dried fast.
Linseed is still used today, sold in places like Home Depot and Benjamin Moore as a wood preservative. Linseed oil is tawny colored, so the red color has to come from something else and there are a couple of main theories about that.
It's said that wealthy farmers often added the blood from livestock slaughtering to the linseed oil mixture. As the paint dried it eventually became a darker, burnt type of red. Ferrous oxide, known more commonly as rust was sometimes added to the oil mixture and there was plenty of it on the farms. Rust also helped to keep the barn's wood structure free of mold and moss and prevented decay.
One of the best explanations for red painted barns is that the practice was brought to the Americas. European settlers carried the tradition of red barns along with them and evidence of using red paint on barns dates back to the 16th century.
The deep red colored paint called "Falu red" or sometimes "Falun red" is said to have originated from a copper mine in the city of Falun located in Dalarna, Sweden. The paint was made of water, rye flour, linseed oil and tailings from the copper mine which has iron oxides, copper compounds and zinc. Often used on Swedish barns and cottages, the paint was found to be a natural wood preservative that was long-lasting like iron. When the paint would wear out and flake, the loose flakes could easily be brushed off and repainted to look like new again.
The paint was cheap and poorer farmers would even use it to paint their houses during the 19 century. The current recipe for Falu red pain was finalized during the 1920's. Falu red is still widely used in the Swedish countryside as it is in the United States but here we call it "barn red".
