Our current dock was built on some old wood pilings that were sunk into the lake about 60 years ago. They appear to be sawn-off telephone poles. Over the years some of them have had their insides hollowed out due to rot, termites, or whatever, so that about half the wood is gone. I was wondering if there’s something (concrete?) that I could pour down into the pilings to make them last a few years longer.
Bump.
I suggest you contact an engineer before doing anything like that. Waterfront construction can be tricky and the permitting process can also be hard.
Adding concrete will add a significant amount of weight to the pile. Depending on what the pile is bearing on (organic silt, for example) and what loading the dock itself sees, it could lead to settlement. Anyway, concrete doesn’t flow that well that it’s likely to get through rotted wood, unless the insides are entirely rotted out.
Usually they are just replaced. These lasted you 60 years and owe you nothing.