There is no such thing as a "silly question" only the lack in asking.
Or so I tell my students.

We currently live in a 1940 rancher on a 12 in slab so I don't worry
about the weight of my 55 g. But that can change once we decide on a
new house. As any one who has ever bought a house knows, you hire an
inspector to look at the house before you sign the papers. If you are
buying a 100 year old house than it is reasonable to think that you
would need some extra support for the tank, just by virtue of the (our
last house was built in 1919 and I didn't feel safe with a 20g in there)
age. But if you buy a new home the wood is new and stronger.

Having said that it was still a good question and the answers were
great.

Vicki