It took a long time for fungi to evolve to consume wood (bacteria too). It took 60 million years for this evolution to take place. Sounds like plastic might be on a faster track according to this article.

Basically wood cells are hard to penetrate, don't provide a food source if they've been air dried, and even in cases where fresh cut wood isn't dried quickly, organisms don't cause enough damage to affect wood's strength. Pretty fascinating stuff.

> Deterioration Without Decomposition. When fresh-cut lumber or veneer is properly air-seasoned, the stored food materials in the sapwood are soon depleted by the respiratory processes of the wood parenchyma cells themselves. If drying is delayed, however, the fresh-cut wood can be invaded by so-called sap-stain fungi and algae, or by bacteria and molds that develop over the surface or penetrate deep into the sapwood by growing through the ray cells from one wood storage cell to another. These organisms use the contents of the wood storage cells as food and thus do not affect the strength of wood seriously; they primarily discolor the wood or alter its permeability. When fresh-cut wood is kiln-dried immediately, the living cells of the sapwood are killed by the heat and the reserve foods are retained in the wood storage cells. If kiln-dried wood becomes wet again, these stored foods can again become substrates for growth of discoloring fungi and bacteria.

Source: https://www.fpl.fs.fed.us/documnts/pdf1984/kirk84a.pdf

"These organisms use the contents of the wood storage cells as food and thus do not affect the strength of wood seriously; they primarily discolor the wood or alter its permeability."

Discoloration only? But then what is rot?

The linked text is titled "Biological Decomposition of Solid Wood". It's pretty fascinating, and also covers destructive decomposition mechanisms.

FWIW, we avoid this problem with wood by pressure treating the wood with poisonous chemicals, so mold and other organisms can eat it.

Another common method is to protect the wood with a layer of plastic (polyurethane, paint, etc). That's evidently out the window...

I thought the way we prevent wood rot is keeping moisture away, painting it is one way to prevent moisture away

That is a common technique I mentioned. Most paints and finishes we use on wood are in the plastics family. So if microbes can eat plastics, that line of defense becomes a lot weaker.

The other way we protect wood is to acknowledge that it will get damp, and pressure treat it with poison so that mold can't grow on it.

I don't think we'll have a huge problem in general but things will become less convenient. Water based paints any consumer can buy at any point and use without worrying too much and get decent results in any color you name are great.

We might have a harder time with traditional limewash. It is rather caustic and takes a long time to prepare. And while you can achieve different colors with it, it's not the uniform easy perfectness modern paints have. It also has to be re-applied periodically, so it's not as hands off.

It's a bit like gyp rock. You can buy these sheets that go up quickly and easily even for the lay person (I've built a wall). Lathe and plaster existed before that and worked well enough. It's a lot more work though.