karenb97•1mo agoMost Upvoted

The day a 20 year fence veteran showed me my post holes were all wrong

I've been putting up wooden privacy fences for about 5 years now, always dug my holes about 2 feet deep for a 6 foot fence, thought that was the standard. Then I'm working a job near Raleigh last month and this old timer named Hank comes by, watches me for a minute, then says real quiet 'son, your holes need to be below the frost line or that frost heave is gonna push your posts up every winter.' I had no idea frost line even mattered for fences, I just figured deep enough was deep enough. So which is it, do you guys actually measure frost line or just go with the local standard depth?

3 comments

3 Comments

james_bell1mo ago

...but see, that's the thing though, I actually gotta push back a little on that @hayden_craig95. I get what you're saying about microclimates but you're overcomplicating it for most of us just trying to hang a fence before the weekend. The frost line map from your local building department is good enough 9 times out of 10. If you're digging 6 foot deep holes based on some theory about your yard's specific soil moisture, you're just gonna burn yourself out and maybe hit a gas line. Plus, 2 feet deep through some heavy clay in Raleigh is already a solid afternoon of work. I think the old timer gave solid advice but it's not like you gotta get a soil scientist out there for a privacy fence.

alicecraig1mo ago

Wait, am I supposed to actually know what frost line means or just nod and dig deeper?

hayden_craig951mo ago

Huh, that's actually a good question. Most people just nod and dig deeper, but here's something nobody talks about - the frost line isn't always the same depth even in the same general area. I've seen it vary like a foot or more just based on soil type and how exposed the spot is. Your yard's microclimate matters way more than the generic map online will tell you. Just something to keep in mind before you trust the standard number blindly.