Overheard a guy at the hardware store say you don't need to treat fence posts before setting them in concrete. That's a disaster waiting to happen.

I was grabbing some lag bolts for a deck repair this morning and this young guy was telling his friend to just throw untreated pine posts straight into wet concrete. Said the concrete "seals it good enough." Man, I've pulled out rotted posts from a job in Eugene where they did exactly that. The moisture wicks right up through the concrete and rots the bottom in like 2 or 3 years. You gotta at least use pressure treated or wrap the base. Has anyone else seen this shortcut backfire bad?

3 comments

3 Comments

robinson.hannah3d ago

I've seen people try the plastic bag trick too... wrapping the buried end in a grocery bag before setting it in concrete seems to trap moisture just as bad.

sean_torres713d ago

Yeah the "plastic bag trick" thing is something I heard a guy at the hardware store warn about. He said polyethylene bags basically turn into a vapor barrier that traps moisture against the wood. I read somewhere that pressure treated lumber needs to breathe or it'll rot from the inside out. The concrete wicks water up into the post and then the bag just holds it there like a sauna. Better to just let the wood touch the concrete direct or use those gravel base methods instead.

keith_rivera191d ago

Plastic bag trick" lol that sounds like one of those ideas that makes sense at 2am but falls apart in the morning. The "vapor barrier sauna" visual is killing me I can just picture the wood sitting there steamed like a vegetable.