Brian from Backblaze here.  Our corporate office in San Mateo is in an old wood building and we&#x27;re on the second floor.  We put a heavy rack full of experimental pods in a closet here, and I was worried it might sink through the floor BETWEEN the floor joists.  :-)   So I put a few layers of extra strong plywood under the rack to distribute the load.  I&#x27;m happy to report no damage or sagging has happened (yet).