On Fri, 7 May 2021 18:16:24 -0400, Ralph Mowery posted for all of us to
digest...


In article ,
says...

Probably linseed oil, that was the good ol wood protectant. It spontaneously
combusts if left in piled rags. If the shed caught fire it would have been a
grand sight.




I live in a small town and about 55 years go there was a fire that wiped
out a city block. The buildings were old and many had wood floors and
about 3 stories tall. Those floors probably had many layers of some
kind of oil on them. The buildings were brick on the outside.

That's probably because they didn't have a proper firewall between units. The
house I grew up in didn't have one. It was a brick twin with the wall
separating the units only coming up to the eaves. The space under the roof
trusses was open, one could climb into the neighbors if industrious enough.
IIRC I don't recall what was used as a separation in the attic. My father had
put plywood down to use as a floor & storage for stuff... Knob & tube wiring.

--
Tekkie