I'm planning to install a privacy fence for my wife and need some advice. I bought 10" concrete tubes that are 6 feet tall since the soil here is super dry-packed and tends to collapse when digging. Is it okay to place my 4x4 posts inside these concrete tubes? Also, is it acceptable for the posts to go only 2 feet into the ground with 4 feet above it? I'm unsure about whether I should add gravel at the bottom of the concrete or just pour it directly. Additionally, I'm in Southern California where the dirt becomes mud when wet, so I thought these tubes would help prevent any collapses. I was also told to use high-strength concrete, but those 60lb bags are really heavy. Can I get away with using 50lb bags, and if I opt for quick-set concrete, does that mean I'll have only a few minutes to work with it?
3 Answers
For a 4-foot fence, going 2 feet down should be fine. Using form tubes is a good idea, but don’t forget to backfill and compact around the tubes once the concrete sets. You can use pretty much any concrete for fence posts; strength isn’t too big of an issue. If you find the 60lb bags too heavy, consider asking someone to help lift the 80lb bags; it's safer than struggling with them alone.
Just a heads up, high-strength concrete refers to its cured strength, not necessarily the weight of the bags. So you can still get high-quality concrete with lighter bags if you know the right mix.
Have you thought about using metal posts? They might require less concrete than wooden ones. Just a thought!
I’m not really experienced with metal posts. I’ve already stocked up on wood screws for this project, and I went with cedar for durability against rot and bugs.
Totally understand the struggle! I can manage 80lbs, but it's definitely tough. I prefer the 50lb bags too.