I was setting posts wrong for five years until a job in Bend.

I used to think a 6-inch gravel base was enough for a 4x4 post in our soil. Then I saw a fence I built in 2019 leaning like the Tower of Pisa after a wet winter. A guy I was working with in Bend last month pointed at the frost line chart for the county and said, 'You're putting them in a bathtub, not the ground.' He was right. How deep do you all actually go for a cedar privacy fence in a freeze-thaw zone?

3 comments

3 Comments

the_kevin19d ago

Forget depth, what's your post spacing? Too close and they'll heave together.

noah_davis19d ago

Seriously, what's the actual rule of thumb then? I've seen decks where the posts are like six inches apart and it feels fine, but my neighbor put his at eight and the whole thing looks weirdly sparse. Is it just about the total span or does post thickness change the math?

the_oliver8d ago

Man, I used to be all about the six inch spacing too. Then I saw a deck last winter where the posts were too close and the whole thing lifted in one frozen chunk. Now I'm with Kevin, spacing matters way more than I thought. If they're too tight, the frost just grabs everything together. Gotta give each post some room to move on its own.