I have a twenty-year-old remote cabin built on what I think are utility pole piers. Most are about 20 inches in diameter. They are all short, about 6 to 12 inches above grade. I think they are creosote-treated. At least one is rotting and needs replacement (from roof runoff, probably). I donít know yet how deep the piers are.
One long side of the 20x30 cabin floor is about 5 inches lower than the other long side. Judging by the sagging of the porch where it attaches to the sill log of the lower long wall, most of the 5 inch drop is from pier settling rather than from the original state of the foundation.
So, I plan on jacking the low side up. I want what I do to the foundation to remain sound for another 40 or 50 years.
So, do I:
1. Keep the original piers if they seem sound and install five inches of ďshimmingĒ, or
2. Keep the original piers and compact more earth beneath them to prop them up, or
3. Replace all five piers on the low long side.
If I replace all five piers, should I use:
1. Creosote utility poles again, or
2. Install 8x8 or 12x12 pressure treated timbers that I paint with copper naphthenate (dock and fence post preservative)
Or, instead of subsurface piers, should I use 1/3 steel drums filled with concrete for above ground pads (resting on mineral earth)?
Do AKDoug or others have any thoughts about it?