[MassHistPres] Can sloping floors be corrected?

[Dave Mountain]

A sloping floor at the second floor with out the same problem at the first
floor is pretty unusual unless the first floor originally had a problem and
something was done to level off the first floor.  I'd start by checking for
rotted sills.  If you can stick a pocket knife into the sill, you know you
have a problem. If the problem is due to rotted sills, then I would expect
to see some sort of independent bracing of the floor joists on the first
floor or a newer floor laid on top of the original first floor.  Contrary to
popular opinion, replacing rotted sills is not a big deal and doesn't
normally require jacking up the house.  A skilled carpenter can replace the
sills one segment at a time.  I once owned a circa 1820 cape with rotted
sills that were so bad that they looked like rich compost and were removed
with a shovel. We simply worked our way around the house, replacing the
sills section by section.

If sills are not the problem, then as a previous reply mentioned, the
problem could be in the exterior wall. Before going further in the diagnosis
we would need to know if the house framing is platform or balloon-frame
construction.