Supporting a large tank on a concrete floor of varying thickness

[kdx7214]

My mom's house recently had to have a sump pump installed to fix a mold problem. When the contractor broke up the floor for the installation they found that the floor varied in thickness from 2 inches to 8 inches.

The wife and I are currently house hunting and I'm making plans for a 300-500 gallon aquarium in a basement family room sort of area. Without breaking the floor I won't have any way to know it's thickness. Would a situation like this be safe? I realize that the dirt beneath the house will have been compacted, just not certain about horizontal stresses and the like.

 

[AlexG]

I would lookup the local building codes for the area you are house hunting to determine what it is. In my area it was 4" of cement over undisturbed earth. If you build a stand to distribute the tank weight over a larger area with lots of legs it will also spread the load over the floor. Depending on how the basement was dug also consider that drain tiles might be installed along the perimeter which is in part why my tanks are 2' from the wall but it was also for access. In the event you don't know the thickness you could always drill a hole with a hammerdrill to check the thickness.

 

[kdx7214]

I would lookup the local building codes for the area you are house hunting to determine what it is. In my area it was 4" of cement over undisturbed earth. If you build a stand to distribute the tank weight over a larger area with lots of legs it will also spread the load over the floor. Depending on how the basement was dug also consider that drain tiles might be installed along the perimeter which is in part why my tanks are 2' from the wall but it was also for access. In the event you don't know the thickness you could always drill a hole with a hammerdrill to check the thickness.

In my experiences, local builders rarely follow the building codes very well. Lots of shoddy contractors and not enough inspectors to check things out. I'm more concerned about finding a house with good, solid floors. My plans already had the tank along an interior wall (if available) or offset from the wall so I can get behind it. I won't be able to take a hammer drill to the basement of a house I don't own yet

I guess the alternative is to get a buddy who's a structural engineer to draw up some plans and reinforce the main floor to handle the stress. That'll be expensive, but possibly the only reliable answer.

 

[Greg P]

If you're super paranoid about it, shop around for someone to survey it with GPR.
As long as the concrete is not fresh (needs to be cured/no moisture) and is over soil it will give you an accurate reading of the whole room's thickness

 

[Copingwithpods]

Pick the house you want and don't factor in the tank. You might not always have a tank but you will always need a house. Don't even bother looking up local codes as no one follows those anyway. After purchase drill some holes where your tank will be, 1/4 x 12" bit should do. If the floor is dangerously thin (anything under 4 inches) the repair is easy and if done by you can be very cheap. Tool rentals, rebar and concrete are all cheap.

 

[Bigtrout]

You could check thicknesses of concrete and pour a 4 inch pad with rebar in it at whatever footprint the tank is if the concrete is thin. That would be fairly easy to do and of course the new pad could be level as well. Alot of basement floors are not very level.

 

[link81]

Pick the house you want and don't factor in the tank. You might not always have a tank but you will always need a house. Don't even bother looking up local codes as no one follows those anyway. After purchase drill some holes where your tank will be, 1/4 x 12" bit should do. If the floor is dangerously thin (anything under 4 inches) the repair is easy and if done by you can be very cheap. Tool rentals, rebar and concrete are all cheap.

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