On Jun 22, 4:42 pm, Drew Cutter wrote:
I ripping the carpet out of my house. The house is around 50 years old.
The stair has several squeaky (where you put your foot). What make a
floor squeaky and what is the fix ? These are solid oak stairs.

The nails have come loose over the years. Then the tread rubs against
the stringer causing the squeak. Pull the old nails with a cats
claw. Then replace with a screw in the same hole. That should hold
it tight.