The wind knocked over part of our wood fence. Two of the wood posts that were cemented into the dirt were uprooted. I figure the best way to fix the fence would be to use new posts (or bust off the old cement) and bury them in the ground with fresh cement. I'm feeling lazy and wonder if I do as good of a job just burying the old posts with the old cement back into the ground. Will it hold? Maybe this is a no-brainer for some folks - useful comments appreciated.
First off if the wind blew the fence down then maybe you should go alittle deeper with the post. As to your next question, even though your feeling lazy it is best to knock out the old stuff (concrete) and pour new concrete post mix. If not then it is highly likely that you will be doing it again. Its pretty easy but time consuming. Good luck
Plywood will rot. Build a form out of 2 X 4's or 2 X 6's around the whole thing and then put an inch cap over the whole thing. Then this in turn will fill the hole and you will have a nice flat surface. If you want to patch it you have to take the old concrete out that is lose all the way to the subgrade then pour a patch but doing this you will still allow a small seam to allow moistuire to get in if it freezes it will pop it up. So the best thing to do is to add a lip of one inch above the whole thing. You will also have to break lose any loose concret e and remove before doing the whole lip. Also put a broom finish on top and this will allow moisture to run off of the concrete.
I would probably pour new cement for the reason that when the cement is wet it conforms to the hole dug and seeps in a bit therefore it seems it would be more stable than digging a hole and putting the existing post with dried cement then filling it in with loose dirt. Also, the ground around the new wet cement would be undisturbed and is still hard, you know, not like the loose dirt that would surround it if you just reburied it.