Floor Load Capacity

[Shenandoah Aquatics]

I am curious to what a typical new house's floor can withstand weight wise. I know that there are a lot of factors but I am curious if putting a stand with 15 20 Gallon Highs would exceed what the floor can withstand

[KBOzzie59]

Yes / No / Maybe

You are looking at at least 2500 combined pounds.

How old is the house?

What shape is the rack?

Will it be on a wall on the perimeter of the house?

So So many variables.

If you want to be 100% certain get an inspection or if the house is new enough find the plans, The load per square foot might be on them.

[Nordlys Fish Room]

I’m assuming your completed rack would be 3000 pounds or so. Put it up against a load bearing wall and span as many floor joists as you can. That way your joists (2x6 probably) are mostly in shear stress where lumber is pretty solid. According to this properties of materials website, you can expect white pine to hold almost 900 lbs/in^2 in shear before rupture.

http://www.matweb.com/search/datasheet_print.aspx?matguid=1bec7114d2524b63826044c3cc6c344c
 

A single 2x6 cross section is 8.25 square inches. Now obviously there are MANY other loads associated with your floor and we haven’t touched on torque/moments but the shear strength of lumber is the main reason the area by load bearing walls is so sturdy.
 

As a safety precaution to help with any extra torque generated (the farther away from the wall, the greater the torque) you should go ahead and add a vertical support underneath some of the joists carrying your future racks. I’m assuming in this scenario that you’re on the ground floor above a crawl space. 
 

Disclaimer: I think you’d be fine with your rack, but I’m not a structural engineer, just an internet idiot. And you asked the internet, not an engineer. 

[Guppysnail]

I don’t know all the great technicals but don’t forget accidental water overflow spill tank crack etc as sooooo many of us have done. This will weaken your structure 

[gardenman]

The weight issue is why a garage makes a great fish room. If the garage floor will hold a car, it'll hold however many fish tanks you want to plop down on it. Things get iffier with interior structures. Even if the floor doesn't break, a large amount of weight in one spot over years can slowly deform the wood, creating a permanent dip in the floor. Wood is bendable and over time with a large load, even the strongest wood will deform. Weird things can happen when wood gets overly stressed. If you want to learn more, Google "wood creep"  as that's what deformation over time with stress in wood is called. 

[BIG GREEN]

On 6/30/2021 at 4:46 PM, alpenglow007 said:

I am curious to what a typical new house's floor can withstand weight wise. I know that there are a lot of factors but I am curious if putting a stand with 15 20 Gallon Highs would exceed what the floor can withstand

you will need to add support for your floor, if not over time the floor will start to sag.....

[lefty o]

floors will sag. key thing is how many PSI. i mean people used to put water beds in everywhere with how many hundred of gallons, but the key is it was spread out over a greater area than say a rack of tanks.