I am looking for advice on how to go about digging fence post holes 42 inches down (to exceed 40 inch frost line) safely.and properly.
I was told that I must manually dig the hole within 18 inches of any marked utility lines. I have these utility boxes in the back corner of my lot (3 of them) as well as drainage sewer my sump pump drains into.
First, the town came out and marked some lines that run in and out of my property line that go to two street lights in front of my house. They weave in and out of the property line over and out a foot or so making it pretty tedious to put my fence as close as I can to the property line. So I am going to do my best and manually dig a few of the holes.
I am confused on how to dig the hole. Some people say use a post hole digger, and others say use a spade sliding along the top horizontally rather than vertically. If I use a spade and dig a trench 42 inches down this seems like a lot of work, and also how would I back fill the hole properly. I plan on using tamped crushed rock for the back fill. Would I have to make some sort of square form to back fill the earth in and fill the post hole properly? Does square vs circle surrounding make a difference? If I used a the post hole digger, how do I safely cut into the ground without worrying about cutting into the line? I feel like I can go slowly, but I don't want each hole to turn into a 4hr project a piece!
Any advice would be great as this is my first time putting up a fence. I don't mind the leg work/labor.. I just want to do the job right and maximize the real estate of my backyard without giving it away to my neighbors.
Also, how deep is the sump pump line usually? The only marking I have of it is from the plat of survey showing it running just past the utility boxes near the property line.