Discussion Preserving post and rail fence posts


Mar 14, 2020
I am going to replacing rotted rails and posts of a cedar post and rail fence. I am not setting the posts in concrete, just setting qthem in sandy soil. The contributors to rotting on the posts are termites and water. I want to treat the section of the posts that will be in the ground with a wood preservative or some other material to protect them and make them last longer.

I was looking at something like Woodlife Crecote but that’s over $100 a gallon.
Any opinions on wrapping the bottom of the posts with something like rubber membrane material like that used to form the sill pan for windows? Suggestions for other products? I am also putting in a couple of inches of crushed stone at the bottom of the post holes.

The other, more vulnerable, parts of the fence are the holes in the posts for the rails and the ends of the rails in the holes. It is exposed end grain so soaks up water. Once the fence is assembled I plan on shimming the end of the rails so they are in the middle of the hole and then filling with foam to keep out water.

FYI, I’m not interested in plastic fencing materials or other styles of fence. It needs to be post and rail.
Thanks for any ideas.

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Oct 15, 1999
Copper green is another product you can use.
I tried dipping posts in a rubber roofing material once. They didn't last any longer.


Diamond Member
Apr 12, 2002
It almost certainly would have to be something that actively discourages, or even kills, the termites.

I remember seeing wooden power poles in Guam (where the termites aren't slowed down by much, other than a super-dense wood, like mahogany), that the termites had hollowed the center out of, leaving them like a straw, capped at each end. These were standard power poles, treated with creosote to discourage insect infestation. Looked like the termites had basically chewed their way thru the 2" of creosote soaked wood (probably spitting it out behind them! LOL), then ate the untreated wood in the center out. :dizzy: