Floor support for new tank

[dromo2189]

Hello i am looking at getting a 210 gallon reef tank. I was curious on you’re guys thought on if it will be a problem. My house is a slab then built with 2x8 running across it. They are every 16 inches. Will this support the 210gallon

[Aiken Drum]

So the floor joists are sat directly bearing on a concrete slab rather than supported on walls at each end?

[Flaxon-Waxon]

I’d reinforce the floor personally. I’m building a 75 gallon with 30 gallon sump, and also have 2x8’s on 16” spacing- had a contractor come in and sister a new joist plus add a second one in between 2 existing joists. Cannot hurt whatsoever and if you’re asking a forum you’re likely already concerned about it.

[Flaxon-Waxon]

Before and after. I felt much better about it…

[Flaxon-Waxon]

Originally Posted by Aiken Drum

So the floor joists are sat directly bearing on a concrete slab rather than supported on walls at each end?

I’m also a bit confused as to the layout of the joists. Figured I’d give my $.02 regardless lol

[Aiken Drum]

I work in building design and although im not a structural engineer i can size up floor and roof timbers from span tables for standard domestic construction. Back in the day i tried to work out what size tank a floor designed and constructed to minimum standards could support. For UK building regulations it came out as something about the weight and footprint of a filled 75g tank. I looked at US building codes as well, and although they use different units to us (feet instead of meters, pounds instead of kilos) the minimum standards where pretty much the same.

Of course, i dont know any engineer that would design to a minimum standard because they always build in a substantial safety factor to cover their liability. Also if the tank where perpendicular to joist direction and was at the end of the span rather than in the middle, the floor could support much more than minimum design. The floor wouldnt fail in the event of overloading either, it would just deflect more than the permissable amount, at least up to a point.

Given all that if someone came to me professionally and asked this question, i could never recommend anything more than what i knew it was designed for and if in doubt consult a structural engineer.

[dromo2189]

Yeah my house is built on slab and sorry it’s 2x6 on top then. The front and the rear wall are weight bearing. What i was thinking is cut open the subfloor and put 2x6 between the floor joist in the opposite way to add support.