Sinking post that will undergo lateral force

[tgibson]

Hello, I want to string lights along a wire on my back patio. The wire will be con nected to my house, and to (presumably) a 4x4 post that I need to sink. I a m looking for some guidelines for depth of the hole, the need (or not) for a footing, etc. I believe the soil is simple, packed earth for several feet .

[Auric Goldfinger]

We don't know your - soil conditions - frost line - the length of the 4x4 sticking out of the ground - the tension/side load on your wire

A wild-ass guess, maybe use a 12' 4x4 and bury it 42" deep.

[Unquestionably Confused]

+1

Obviously use PT wood. I would also put some gravel in the bottom of the hole, maybe a cookie (just a dab of concrete allowed to harden before finishing the job.)

Can't hurt to "paint" the post end and lower 40" with roofing cement to further seal it.

Then set the post plumb and finish with a bag or two of Sakcrete.

[tgibson]

connected to my house, and to (presumably) a 4x4 post that I need to sink. I am looking for some guidelines for depth of the hole, the need (or not) for a footing, etc. I believe the soil is simple, packed earth for several feet.

I don't know how to describe the soil conditions other than as packed earth ...perhaps clay deep down? It's in Northern California at sea level in the agricultural belt. The temperature rarely reaches the freezing point. The p ost would need to 8' (8.5' better) out of the ground.

[Unquestionably Confused]

That 12' 4x is what you need then. In your circumstance you don't need worry about the frost line/heave but that depth will give you all the lateral stability you need.

I'd still (unless you're very dry there) go overboard on protecting the section of the 4x that's in the ground.

[bob haller]

why not use direct burial cable?

or protect with conduit?

[tgibson]

The cable is just to support the string of lights. The lights will plug in conventionally to an outdoor outlet.

[Jerry.Tan]

A string of lights could mean something like christmas lights or some lights that are really heavy like they use for industrial apps. It would help for you to explain the lights.

If they are just those patio lights (like christams lights), all you really need is one of those metal posts like they use for STOP signs. Just get on a step ladder and drive them in the ground with a sledge hammer or T-post driver. That would save a lot of work.

[Dean Hoffman]

This

shows a corner post for barbed wire livestock fencing. The corner posts have a lot of stress on them because the fence wire needs to be tight. It's with a fence stretcher before being fastened. This second picture might be more what you're after. It looks like a gate post for fencing. Burial depth is usually three feet or so in my area. I set posts to mount electrical panels. One trick to make the post solid is to pour dry gravel mix around the post. I tamp it with a ground rod since I "always" have one along.