Compression Post - Cabin Sole issue
I have a 1979 i28. We are almost complete with that and additional structural repairs.
The Compression post may shrink a bit, ours was about a 1/16" to 3/32 shorter than the bulkhead it is attached to. The real problem is too much load on an improper material, i.e. the 3/4" plywood cabin sole.
On our boat the post loads down on top of the plywood cabin sole and crushes it, we had a bit more than 3/8" squeezed out of the sole and a slight deformation on the tops of the floors the sole rides on. I believe it totaled about 1/2" "crushed out".
On the i28 I race on, they had installed a plate as a repair. When they adjust backstay tension they still pull until the head door almost jams...
First off, how about a more details regarding your boat, like do you have a teak cabin sole or just the plywood and carpet...?