Any structural engineers out there?

[MikeP471612]

Help me figure this out. I want my 190g tank on our main floor. The house was built in 2002. The joist manufacturer says they are built to handle 10lbs per sq foot of dead load and 40 lbs per sq foot of live load. My tank dimensions are 60"Lx24"Wx30"Tall. I estimate the tank will weigh about 3000lbs when all is said and done. The tank will sit perpendicular to 3 joists and the joist are spread 18 inches apart. The tank will also sit parallel to a wall that goes all the way down to the basement (I don't think its a load bearing wall though). There is also an 'outside' wall perpendicular to the tank about 3 feeet away. I've asked a few people including an architect and no one has said I can't do it, but the builder of the house said I should talk to a strucural engineer to be on the safe side. I called one in town here and the cost was about $500 bucks . Can someone help me out and set any doubts I may have aside? I guess I'm just getting worried cause I'm about to move the tank from the garage into the house.

Thanks a lot

 

[Shnabbles]

i have a 180 im setting up now and i reinforced the floor... It corses 4 or 5 joists and sits in front of a load baring wall and 2 feet in front of the steel beams that are in the basement...

Better safe then sorry.

 

[MikeP471612]

I would definitely reinforce the floor if I could but my basement is developed. I'm really hoping that the original design is strong enough.

 

[humuhumu]

It's really very difficult to provide such an answer without having seen structural drawings or having made a site visit. You mention "joist manufacturer" indicating that you have "pre-engineered" lumber installed. What I would do is find out who manufactured your joists and check on their website for the structural specifications. Look for stuff like allowable span tables which have uniform loads (i.e. dead loads and live loads) and hopefully, concentrated loads (i.e. from your tank). You mention that your tank can cover 3 joists which are at 18" on center (actually, they're probably 16" on center which is a multiple of a 4 foot sheet of plywood). Anyway, assuming the joists can share the load equally, each would be required to support a concentrated load of 1000 pounds. I would look into the specs to see if this is within allowable values. Additionally, you may want to call the manufacturer's engineering division directly and pose this question to him/her. You can pretend that you're planning to use their product and want to make sure it is adequate. They're always very eager to "help" you to specify their product. In my part of the country, the most prevalent "pre-engineered" lumber manufacturer would be www.tjm.com. You could browse through their stuff to see if anything is close to what you have and make your decision based on what you find there.

I'm not sure what your local building codes are based upon, but the building codes in my area requires that the building be required to support a 2000 pound concentrated load, spread out over a 2x2 square region, located anywhere. This criteria is somewhat similar to your situation.

That being said, I wouldn't recommend placing such a large tank on a framed floor which doesn't have framing directly supported by the foundation (i.e. bearing wall, posts, etc...). Even if the joists are "adequate" strengthwise, you may have issues with long-term floor deflections, bouncy floors, etc... and all the complications associated with excessive deflections (i.e. cracked finishes, feeling the floor is "unsafe", etc...). At the very least, I would recommend taking measures to reduce the load per joist such as doubling up the floor joists below the tank, adding blocking between joists under the tank, adding a framed, rigid, platform above the flooring below the tank stand.

I know this isn't a definitive answer to your question but I hope this gives you something to go on.

Good luck,
Alain

 

[Shnabbles]

could you put a little 6 foot wall in the basement directly under the tank?

 

[humuhumu]

<a href=showthread.php?s=&postid=9355516#post9355516 target=_blank>Originally posted</a> by Shnabbles
could you put a little 6 foot wall in the basement directly under the tank?

Or even a couple posts and a beam? Could be all 4x sized lumber.

 

[humuhumu]

[No message]

 

[MikeP471612]

The room right under where the tank will sit is a bedroom. So I can't reinforce anything. In that room a 1/3 of the ceiling is lower indicating there is some duct work in there too? Is there a way I can tell if the wall sitting behind the tank is load bearing?

 

[humuhumu]

<a href=showthread.php?s=&postid=9356895#post9356895 target=_blank>Originally posted</a> by MikeP471612
The room right under where the tank will sit is a bedroom. So I can't reinforce anything. In that room a 1/3 of the ceiling is lower indicating there is some duct work in there too? Is there a way I can tell if the wall sitting behind the tank is load bearing?

One way is to trace the wall down to the foundation. Typically, there would be some type of continuous concrete footing at the bottom if it were bearing. If it actually has a foundation then yes, it is a bearing wall.

Another indication is if the ends of the joists the tank will be sitting on are terminated on that wall. This would indicate that wall is supporting the joists but, unless it has a foundation, it doesn't really do any good.

 

[indianafishkeeper]

Well if it doesn't hold then whoever is sleeping in the bedroom below will find out the hard way... Just a thought.