Why are barns red?

[calliarcale]

Growing up in the Midwest, I’ve seen a lot of barns, and I know a lot of country folk. I’d always been told that the reason for the iron oxide wasn’t merely hardness; it was because iron oxide works an antimicrobial. That is, it helped the wooden structures resist rot, and possibly also insect damage. Modern paints have different ingredients that do the same thing, so barns don’t have to be red anymore. (They don’t have to be wood anymore either, as metal prices have come way down since the 19th Century. My inlaws barn is made of prefab metal sections, for instance.)

It seems silly to me that iron oxide would just accidentally catch on as barn paint unless it actually did something useful.

Original article:

Why are barns red? Why is New York called the Big Apple?

[gonzomax]

Barns are read because they have lettering on the sides.

[filmore]

Iron oxide is quite common. Farmers are frugal and probably don’t really care about what color their barn is. They just wanted something economical to protect the wood. I imagine now they keep it red out of tradition since all paint colors are the same price.

[Exapno_Mapcase]

I don’t know of any evidence that iron oxide makes for an antimicrobial paint. You’d think that this would be widely known and deliberately used if so. But I don’t see any references that indicate it.

“Always been told” isn’t much to go on. Can you provide any cites at all?

[Siam_Sam]

I once read the reason red paint was used, for barns and schoolhouses alike, was it was the cheapest. Really. Has anyone else come across this?

[Exapno_Mapcase]

@Siam_Sam

I once read the reason red paint was used, for barns and schoolhouses alike, was it was the cheapest. Really. Has anyone else come across this?

It’s sorta like saying that the Civil War was caused by slavery. People, like the OP, occasionally give other explanations, but why? Cheapest is always the correct answer.

How Stuff Works

As European settlers crossed over to America, they brought with them the tradition of red barns. In the mid to late 1800s, as paints began to be produced with chemical pigments, red paint was the most inexpensive to buy. Red was the color of favor until whitewash became cheaper, at which point white barns began to spring up.

If you Google “Why are barns painted red”, you soon figure out that everybody loves to rip off How Stuff Works. Usually without any credit. It’s like Introduction to Plagiarism on the first results page.

[Melbourne]

@calliarcale

It seems silly to me that iron oxide would just accidentally catch on as barn paint unless it actually did something useful.

Original article:
Why are barns red? Why is New York called the Big Apple? - The Straight Dope

You have iron-oxide red barns? For how long has that been the case? Most of the red paint I have seen has been red-lead.

Lead oxide makes up 30-60% of a red-lead paint. It’s not just a pigment: it is part of the mechanical structure of the paint, like the fibres in fibre-glass.
It also protects the plastic of the paint, and the covered structure, from sun damage, has an anti-microbial effect, and encourages cross-linking in the oil of the paint as it cures.

If you actually had red-iron-oxide paint (rather than just a modern replacement for red-lead), presumable it had some similar properties

[Cheshire_Human]

I don’t have a cite for this, but I heard that it was because there was a really nasty red-staining clay mud found somewhere in the US, that made a good paint pigment, because it wouldn’t wash off, and was good at preserving wood. Anyone who wants to track down the “red barn” tradition might want to look into that.