Supporting floor above basement for a 150 gal

[JZinCO]

Hey everyone. I'm getting the GF a 150 tall with either 55 or 29 g sump so I can have her old tank
It's going on the ground floor with a mechanical room in the basement below.
At this point, I feel alright about the stability of the floor, provided it it supported. The tank will go on an outside wall, parallel to the floor joists probably sitting on two spans ( I'll have to confirm) but will be about 1ft from the concrete wall in either direction (close to a corner. Depending on how inset the concrete wall is from the exterior wall it may be <1ft)). I want to support the floor for piece of mind.

What do you guys recommend? I know floor jacks are an option but I was thinking of making floor to joist shelving in the basement, using 2*4s for the uprights. I welcome any other ideas or tips.. I'll probably run it by a friend who is a great general contractor but assume I'll only hear a gut check.rather than precise answer

 

[mattgumaer]

I'm no expert (very, very far from it) but, ideally, as you probably know, the tank should be perpendicular to the joists at a wall. This 1) spreads the load across more joists; and 2) puts the load close to where the joists are supported (assuming the wall is an exterior wall or has a structural wall beneath it).

By placing it parallel to the joists, you're doing two things: 1) reducing the number of joists that support the load; and 2) moving much of the load away from the area where the joists are supported.

So, I would think the two solutions to this potential problem would address the two issues created: 1) spread the load across more joists; and/or 2) support the joists at the end of the tank furthest away from the edge where the joists are already supported.

I would suggest considering floor jacks or posts for the two joists the tank sits on. I would not use 2x4s, as they will flex, unless you do something to stiffen them up. I also would consider using cross-bracing across the joists in the area, including at least a couple of the joists to either side of the tank. This should help spread the load to joists outside the two joists directly under the tank.

To get a more specific answer, you'll probably need to provide additional information on joist size, joist space and joist span as well as a engineer (which I am not). Good luck.

Matt

 

[homer1475]

I would think(I'm no way an expert here) that creating floor to ceiling shelving with 2x6's instead of 2x4's as shelve upright's/jack studs on the floor joists would be plenty of bracing. This also depends on what your floor joists are made from.

 

[JZinCO]

Thanks. Good point about 2 by, both of you. Heck I have no problem with even 2*8s for the shelving uprights and also adding plywood skin and/or x-bracing to the upright for addtl support.
Personally I don't see too much of a parallel vs perp. issue considering that the load is being transferred to the basement floor and given that the 2*8 joists aren't allowed to flex using shelves. Am I missing something?
Also, if I do blocking or x bracing within the floor joists, are you talking about one long piece perp to the floor joists and under the floor joists, or blocking between individual floor joists?

I'll go look in the large tank forum and see what people have done. I feel like alot of people have put two floor jacks underneath and called it a day.

 

[ca1ore]

What many people fail to recognize is that it's not so much about structural failure but floor deflection that then puts pressure on the tank in ways unintended by the manufacturer. It is my lay-opinion, that deflection is the cause of many tank failures.

I would never run a large tank without some kind of structural support at or near the front of the tank. That said, your approach to do shelving with 2x4 supports (though I would sister two of them for each post) would be more than sufficient. As long as you have the vertical support columns, running parallel to the joists will be fine.

 

[MelloW33]

I think your 2x4 or 2x6 shelving will be more than sufficient.

I have my 150 running perpendicular to 3 joists and supported by block. Way overkill but better safe than sorry!

 

[JZinCO]

Thanks all. Yes, I think the shelving will cover the entire footprint of the tank. The tank itself is 4ft long by 2ft wide. I will make sure that the uprights will sit directly below the joists. If I'm envisioning how it will work the load just transfers from the plywood floor to the joists to the shelving unit. Instead of joists sagging, the weakest point is probably going to be the shelving uprights wanting to rack side to side. Right? Hence the benefit of sistering, cross bracing and/or a plywood sheet to keep the shape square..
Just making sure I understand this. My contractor friend just put in a 12' high deck to house a sun room with hot tub so now that I think about this, whatever suggestions you guys have, I will run by him.

I'm still curious about blocking too. That just makes sure a joist doesn't sag more or less than a neighboring joist, correct? So if I block out enough spans as to block to a joist without the load, that should be effective? Should I block out even further to spread the load or is that not effective? Are we talking just butt joints with what kind of fasteners?

 

[ca1ore]

Blocking doesn't really address adjacent sagging much, it's more to prevent joists from twisting.

 

[ericarenee]

Blocking doesn't really address adjacent sagging much, it's more to prevent joists from twisting.

This is actually not true.. when you bridge.. its called Bridging not blocking. When done correctly with Sold tight cut blocks from band board to band board in two rolls it ties the whole floor together making each joist stronger together then they are by them self...


I will add that unless are in the this trade its hard to understand... But bridging still does not replace proper support..


thanks for reading

 

[JZinCO]

Hey everyone. Just an update with what I am doing.

I was able to rotate the tank so that it will be sitting on three joists (perpendicularly)

To illustrate what I've done consider a wall:

Using 2x4's, I spanned the entire length of the basement room. I have a double plate. The top plate starts on top of the foundation wall, acting like a king stud (so great support there!). Underneath the double plate is a double header. Then underneath that I have three double cripple studs ('trimmer' in the diagram). Two are placed underneath the would-be corners of the fish tank (so, about 3" and 4' from the foundation wall). One is at the far end of the room (the room is 11' wide). Also, at 6' from the foundation wall is a cripple with king stud. I have a sole plate running along the bottom to spread the load a little across the basement floor.

Everything is cut, and minimally nailed. My general contractor friend will come by, sign off on it and we will put in the final nails.

This has been fun though, a little nerve wracking when I was jacking up the joists. eek. I also ran into some issues because I was making all my cuts so that my finished product would been square. Of course the joists aren't level with one another and of course the basement floor isn't level...

and in case anyone is wondering why I make the supporting structure 11' wide.. I dunno. That's what my friend told me to. On the plus side, it firms up the floor for all of my above room and, in the basement, provides 11'x2' for storage shelves.