My father in law swore by old motor oil for wooden fence posts

He told me to dump used motor oil on the bottom of the post before setting it in concrete. Said it would keep the wood from rotting for decades. I gave it a try on six posts in my backyard about three years ago. Sure enough, those posts are still solid as a rock while the untreated ones nearby are starting to get soft at the base. I know it's not exactly eco-friendly (like, at all), but the man knew his stuff from working construction in the 70s. Has anyone else tried this or got a better trick for preserving ground contact wood?

3 comments

3 Comments

shane_bell3d ago

Bet the runoff is killing the good bugs in your soil though.

wood.uma3d ago

Keep the oil away from concrete - it'll weaken the concrete bond.

quinn1613d ago

Oh man, you're totally right about that! I learned that lesson the hard way last summer when I was resealing my driveway. I had a little drip from the oil can and didn't think much of it, but a few weeks later that spot looked all crumbly and weak compared to the rest. What worked for me was putting down a big tarp under the car whenever I'm doing any oil changes or fluid top-ups. I also keep a bag of kitty litter in the garage now (seriously, it's great for soaking up spills fast, just sweep it up before it soaks in too deep). Saved me from having to patch that whole section of concrete again.