A job in Boulder taught me to always check the frost line first

We were setting posts for a cedar fence on a slope there last fall, and the ground seemed solid. The client wanted a 6-foot fence, so we went with our usual 3-foot deep holes. By spring, half the posts had heaved almost 4 inches out of the ground from frost. The local inspector told me Boulder's frost line is 36 inches, not 24. Now I call the city building department for the code before I even give a quote. Has anyone else had a frost line surprise in a new area?

3 comments

3 Comments

noahbaker2mo agoMost Upvoted

Yeah, that'll ruin a fence fast. I keep a note on my phone with frost depths for every town I've worked in. Saved me in Denver last year where it's 30 inches, not the 24 I was used to.

paul23324d ago

Four inches? Man, I used to think frost heave was overblown until I saw a buddy's fence post lifted clean out of the ground like that. Changed my whole approach to digging posts, no question.

jana_henderson522mo ago

Four inches of heave from frost? That's a brutal lesson to learn the hard way.