Saw a fence in Savannah that made me rethink post depth

I was down in Savannah, Georgia last month visiting family and I saw something that stuck with me. A whole row of nice, new-looking privacy fences in a neighborhood had a serious lean after a big storm. The weird part was, the posts looked solid and the concrete footings were huge, but they were only set about 18 inches deep. The ground was super sandy, and I guess the wind just pushed them over. It got me thinking about the old rule of thumb for post depth. Some guys swear by the one-third rule, setting a third of the post in the ground. Others, especially in soft soil or high wind areas, say you gotta go deeper, like 30 inches or more, no matter what. This Savannah job clearly needed the extra depth. What's your go-to method for figuring out post depth on a new site? Do you stick to a set rule or change it up based on the soil?

2 comments

2 Comments

sandraf841mo ago

Those deep footings are a waste of time in most yards lol

emery181mo ago

Know exactly what you mean... saw a whole deck collapse in a neighborhood near me after a wet winter. The posts were set fine for clay, but the builder didn't account for the slope and water runoff. It's never just one rule, you gotta look at the whole picture.