I'm thinking of installing a rather large aquarium on the 4th floor of a residential high-rise which has a total of 27 floors. I plan to place it directly against a concrete column with a diameter of around 4 feet.

I think the main issues are:

  1. Overloading the slab such that it falls through the slab.
  2. Not overloading the floor to the extent that it falls through the floor but overloading the column.

Who do I need to talk to in order to find out if this is feasible before the project actually starts? The building manager, a civil engineer, or....?

The load is spread over about 8.5 ft². Are high-rise buildings designed to support live loads of this type and magnitude?

  • 2
    $\begingroup$ I'm curious as to why the weight to area ratio is so high - 8500lb/8.5ft^2/(density of water) = 16ft which is quite a bit taller than I'd imagine your aquarium being? $\endgroup$ Oct 20, 2015 at 17:13
  • $\begingroup$ @yjo I thought the same thing. Perhaps the aquarium is on legs, whose combined area is 8.5 ft$^2$...? $\endgroup$
    – Carlton
    Oct 20, 2015 at 19:18

1 Answer 1


The answer is that you will have to have an engineer look at it if you want an "official" answer. The details below may help to show you whether or not it will be feasible.


The load that you gave is $8,500\ \mathrm{lb}/8.5\ \mathrm{ft^2}=1000\ \mathrm{lb/ft^2}$.


Floors are designed for typical loads. In addition to the weight of the floor itself (dead Load), the floor is designed for a live load that takes the form of a uniform pressure. The exact amount used depends on the the expected use of the floor. You can see the variations from the table on page two of this document.

Typical apartment (residential) floor loads are $40\ \mathrm{lb/ft^2}$.

Your Situation

As you can see from simply comparing the loads, you will be locally applying more load that the floor was designed for.

As you have noted, there are some mitigating factors it your situation.

  1. You are placing the load near a column.
  2. You aren't applying this same load to the entire floor.
  • 7
    $\begingroup$ The answer is that you will have to have an engineer look at it if you want an "official" answer. Second this. Don't add heavy loads to a structure without consulting an engineer! $\endgroup$
    – grfrazee
    Oct 20, 2015 at 13:36
  • $\begingroup$ One other thing to consider would be that if you live in an area where earthquakes are a concern, the engineer will have to look at the seismic loading which probably matters more to the slab and the column than just the weight. $\endgroup$
    – Ethan48
    Oct 20, 2015 at 15:27
  • $\begingroup$ "Typical apartment (residential) floor loads are 40lb/ft2." How does that compare to just walking about on it? Surely that's putting rather more than 40lb in a rather smaller area than a square foot? $\endgroup$ Oct 20, 2015 at 15:45
  • 1
    $\begingroup$ @JamesThorpe nationalofficesystems.wordpress.com/2011/11/30/… If its the same as that, then it seems its an avg calc. $\endgroup$
    – coburne
    Oct 20, 2015 at 15:58
  • 1
    $\begingroup$ @JamesThorpe, the 40 psf live load for apartments is a typical uniform load applied across the entire floor space. Yes, a human adult will apply more than 40 psf in a concentrated area, but a family, including all its furniture and stuff, theoretically will not apply more than a 40 psf average load on the space. $\endgroup$
    – grfrazee
    Oct 20, 2015 at 16:36

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