Checking Floor Strength

[PicassoDan]

Well, if it will help you sleep better, an engineer is a good idea. Although he/she is going to want to see the floor and what is supporting it. Any way to peel back carpet or pull up a piece of flooring?

 

[bpro32]

I'm not sure what you're asking.

Let's say someone is putting a 150g tank in a room. On average you can say a tank setup with sump and stand and what not will weigh about 10 lbs per gallon, so 1500 lbs. Let's make it safe and use a 15% margin of safety, call it 1725 lbs. If the OP wouldn't worry about 10-12 average people standing in the room during a party, they shouldn't worry about a tank in the room either.

10-12 people spread out in a ~20x20 room? No problem. 10-12 people bunched within a 7x2.5 area for months at a time, I’d be more concerned.

 

[PicassoDan]

The other thing to think about is how much do you want the floor to bounce and the tank to rock when a few people are gathered around it? I put a 120 gallon tank against an outside wall of my house with 2x10 floor joists 16" O.C. running perpendicular to it. I still added a new wall (new sump room, actually) in the basement because I didn't want the tank to bounce.

The 120 is right above the frag tank in this picture:

 

[emvanburen]

I found that the engineer I used was very very conservative. He modeled the floor for performance (deflection etc) with all sorts of safety factors. He ended up preparing drawings for our contractor to use to reinforce the joists under the tank. He was worried about very technical nuances - did this wall have a footer under the concrete (no), was that perpendicular wall "load bearing" despite having a double top plate, up to the joists etc (no)- and thus ignored many structural elements of my home which would carry load but which he was uncomfortable with. And I understand why - he isn't going to take that risk himself. It was very expensive...

 

[PicassoDan]

Sounds like a typical engineer...over-analyzing and overly-conservative.

trust me, I'm an engineer...

 

[jim_fitz]

The real thing to consider is water depth
a shallow tank exerts less pressure than a deep one

im not a structural engineer but i am a civil engineer

 

[sp1187]

I'm not sure what you're asking.

Let's say someone is putting a 150g tank in a room. On average you can say a tank setup with sump and stand and what not will weigh about 10 lbs per gallon, so 1500 lbs. Let's make it safe and use a 15% margin of safety, call it 1725 lbs. If the OP wouldn't worry about 10-12 average people standing in the room during a party, they shouldn't worry about a tank in the room either.

my thought is, if the stand will hold it up, with far less structure than a floor, why worry about the floor, unless you have a beast of a tank.

 

[Potatohead]

my thought is, if the stand will hold it up, with far less structure than a floor, why worry about the floor, unless you have a beast of a tank.

Like I said I wouldn't worry, unless it was around 2000 lbs or more. Even then it is probably no problem, but at that point I would want to be sure.

I have a 6' 210g setup in my house, not a reef tank. it's 30" tall. The guy I bought it from had it on a second floor of a townhouse for over three years with no problem.

 

[Big C]

I was lucky enough my basement wasn’t finished under the location. That enabled the engineer to inspect the supports, condition of the joists, quality of joists, etc. He reviewed the calculations with me and assumptions. Was there safety factors yes. I guess as an engineer myself I could have ignored them and gone with my gut feeling and did nothing. Actually I thought his assumptions and factors where pretty reasonable.

For safety factors I guess it all depends on field conditions and what is existing, there are a lot of unknowns. The engineer got hired to make sure the joists don’t fail and that’s going to come with some safety factors.

I had asked my local reef store if they had any contacts but they didn’t. I shared the report and contact with them as they were interest and could pass it on to the next person.