Not all floors are built 16" on centre anymore. Some are 12", some use 2 x 10's, or engineered joists (look like I beams).
There are seismic codes in BC now too, lots of houses utilize huge laminated beams (that can't be drilled for piping, plumbing or electrical).
Steel I beams are also the norm in 3 storey detached structures which are bearing the load 30 feet up to the peak of the roof. I see it all the time, as I need to run my pipe all over the house.
Single family dwellings are built different from townhouses, which are different from rowhomes, which are different from apartments, etc, etc.
If you have in-floor heating there is 1 & 1/2 inches of concrete above the sub-floor.
Some builders don't want drops or bulkheads in the basement, so trades need to drill holes (sometimes up to 8 inches) in joists to run ductwork or pipe.
What if
eternitybc is planning a tank in a spot that is drilled with 8" ductwork? Fail.
An Engineer needs to see final inspection drawings to assess if a floor can handle the load. Having one come to the house is as useless as a home inspector, they can't see through walls and floors.
Any Engineer is going to tell you your floor can't handle it, because they don't want to be liable.
I can guarantee an Engineer will tell you to open the ceiling below the tank and beef up the structure by sistering every joist. Glue with PL Premium and nail (screws fail seismic shear).
They love to over engineer, so probably also add 2 posts (steel) with a two 2 x 10 laminated lintel minimum. Of course the 4 - 6" concrete slab you have in the basement needs to be thicker too, to support the steel posts.
Then they will spend 3 - 6 weeks making some fancy drawings that you can submit for a building permit.
I just saved you $5000.
