PDA

View Full Version : Max size on main floor with floor joist?


wheelman1976
03/01/2014, 03:59 PM
I'm investigating getting into the hobby and have been thinking about where I would place a tank. While size would not be an issue putting a tank in my basement where there's a poured slab, I just don't see myself going down there much to enjoy the tank other than to service it. That leaves the main floor that is floor joist based. I am thinking about putting it near the middle of the house where there is a header running the width of the house for support (it would be just off of it based on my calculations). My question is what's the max size tank someone would put on a joisted floor and not have issues with support?

James77
03/01/2014, 05:16 PM
What size is the header...is it a main beam? What size floor joists? Newer or older house? Are pics possible? there are a lot of variables that come into play. You can also hire pretty much any competent carpenter/contractor/handyman, and they can give you an idea.

If it is running parallel to that and right against it, and perpendicular to the floor joists...you are not going to have many issues. Keep in mind, it is also possible to add additional support with things like lolly columns or even upright 4x4's. What size tank ar eyou looking at?

I have a 4 foot 120g tank in a very old house(nearly 100 years old), and I would not have a problem with a 6 footer (180g) or even 8 footer(300-1sh)as I would be spanning more joists. I ran a 175g about 6 foot off a support wall in my even older tenemnet house in the past by using a header(2-2x10's sandwiching 1/2" plywood and spiked) with 2 lolly columns.

wheelman1976
03/01/2014, 05:26 PM
That's my issue, I'd be coming off of the middle wall/header perpendicularly (just 2x4 built 7 years ago). I'd be catching two joists at best.

James77
03/01/2014, 05:51 PM
I wouldn't call anything 2x4 much of a header at all :)

Are you able to add lolly columns in the basement at all? In that case, the tank could span 2 joists in parallel, just have supports on either end of the tank and it would be enough. Several ideas pop in my head...but they all invlove supports in the basement....

mighties_keeper
03/01/2014, 05:55 PM
If your are worried add a floor joist support under it. I have a friend that I need to do this for his 300 gallon. His house joists run parallel with his tank and his is freaked that his tank will fall through the floor.

wheelman1976
03/01/2014, 06:16 PM
Too late to add anything as the basement is finished. Hence wondering how big I can go safely.

Menace2Sobriety
03/01/2014, 06:20 PM
Most outer walls are pretty safe as the floor sits on TOP of the concrete foundation.

You'd NEVER have to worry about a tank going through the floor... I mean... a 200 Gal at 2000 lbs is no different than a group hug with you and 8 of your drinkin buddies. BUT.... here's the problem... if the floor bows a bit.. the stand bows... the stand bows, the bottom of the tank bows... the tank bottom bows and the sides try to "toe in" at the top and POP! There goes your seams on the tank!

My suggestion.... find an outside wall to put the tank against. Then you'll have no worries.

Menace

James77
03/01/2014, 07:16 PM
Most outer walls are pretty safe as the floor sits on TOP of the concrete foundation.

You'd NEVER have to worry about a tank going through the floor... I mean... a 200 Gal at 2000 lbs is no different than a group hug with you and 8 of your drinkin buddies. BUT.... here's the problem... if the floor bows a bit.. the stand bows... the stand bows, the bottom of the tank bows... the tank bottom bows and the sides try to "toe in" at the top and POP! There goes your seams on the tank!

My suggestion.... find an outside wall to put the tank against. Then you'll have no worries.

Menace

But those 8 drinking buddies are not standing there hugging for years.....unless they are really drunk :)

James77
03/01/2014, 07:18 PM
It is really hard to say without seeing exactly what you are dealing with. I would place a 75g pretty much anywhere on a floor without too much worry. When you start getting over 100-120g, the weight really starts adding up.

What kind of tank are you hoping for? Just the largest possible? A longer or shorter one, wider or narrower?

SGT_York
03/01/2014, 07:26 PM
I'm a bit confused.

A header could not be 2x4's. Please define what you mean by header as there is no way your home could be built that way and still be standing. (you can't even use 2x4's to cover doorway headers. (on a supporting wall the only place headers are required)

If it is a header, never put anything of significant weight directly over a header. Header's are the weakest link in the house structure.

Generally any home built within 7 years could easily hold a 180Gallon tank, but I wouldn't run it parallel to the joists, unless it is very close to a supporting wall underneath.

Oh and please ensure all stands are built so they won't ever bow if the floor bows the stand should just float perfectly square over a bowed floor.

wheelman1976
03/01/2014, 09:00 PM
What I'm trying to explain is in my basement I have a center wall that runs the width of the house, it is situated on footings and a concrete pad. It's two by four based, one side is drywalled for the finished section, the other is open and that is where my furnace room is. Above on the main floor is where I'm looking at placing this tank, if you were looking over things on a blueprint layout, this tank would sit perpendicularly to one side of this wall, essentially sitting on 1 or 2 of the joists that come off of it. The floor joists rest on this middle wall and extend to the outer walls.

I am thinking of a 65 or 75 gallon set up at this point to be safe for the floor and of decent size to have some nice fish and corals in it and be easy to maintain. I'm assuming I'd have a sump under it bringing it up to close to 100 total gallons, so I guess that's my concern, is 100 gallon too much for a joisted floor?

OutsideBrian
03/10/2014, 08:49 PM
Aside from the 2x4 wall your floor joist are what size? 2x8,10 etc and what are they spaced at?
Simple math say a tank weighs 10 pounds per gallon a 75 gallon weighs 750 pounds.

wheelman1976
03/10/2014, 09:20 PM
I'll check tomorrow. Pretty sure they're 2 x 12, will have to check spacing but what's code? 12 or 16 inch on center i believe? Like I said, if I catch two of them I figure that's being lucky.

davocean
03/10/2014, 09:41 PM
Pics and or plans are needed to answer your question correctly, anything else is an educated guess at best.

PHRN
03/10/2014, 11:37 PM
While the particulars will make a difference, I have had a 75 on the second floor of a 100 year old house for over a decade with no problem. This was years ago, now tank (soon to be another) sits on concrete slab:) If you can do a 75 you can go longer and get more gallons because you'll sit over more floor joists if your 6 or even 8 feet long. It's going to suck buying all those LED lights though :)

ca1ore
03/11/2014, 04:51 AM
is 100 gallon too much for a joisted floor?

Well, I'm not a structural engineer (are any of us) and the best advice would be to consult one. If you don't feel like doing this, and I never did, then I think if I understand your setup properly you will be fine with the tank size proposed. It would be ideal to try to catch two joists, though the floor will distribute some of the weight. 2x12, spaced 16 on center, are pretty strong, and deflection will be minimal based on your description of the location of the weight bearing wall in your basement.

Dankrencisz
03/11/2014, 05:49 AM
My neighbor, a general contractor for high end homes, said I'd have zero problem putting a 220g on my first floor. Home built in 1993. Put it against an outer wall (he told me)

Take it for what it's worth. I trust him because he'll be the one I call to come clean up and rebuild my house if my house collapses. Lol.

mkoop
03/11/2014, 06:01 AM
I agree any home built in the last 7 years should have no issue holding that size tank on the main floor. That being said there are far too many variables for anyone to blindly give you a definitive answer. I'd suggest paying a structural engineer to come give it a look if you are worried about damage to your home and are unsure... In the long run the price would be worth the peace of mind imo

Dankrencisz
03/11/2014, 06:34 AM
in the long run the price would be worth the peace of mind imo


+1

SGT_York
03/11/2014, 07:05 AM
A structural engineer won't do much more than look up your building code at the time it was built and make an educated guess. (age of home is obviously a factor)

If your home is built in a city (or any place that has a building code) you are good to go with your tank, Feel free to put up to a 120 anywhere provided your home is less than 35 years old or so. For most buidling codes (I only know the north, west, and south no experience with new england codes) you will be fine with a 180 ran perpendicular to the joists unless the building was damaged and construction was up to par.

Code requires a live load (not the weight of the house) that is suited for the task.

(also don't try to put a tank on the same joists as a bathtub or really heavy piano or such)

If you are contemplating a 120-180 or above or have other concerns about your house a few hundred bucks for an engineering assessment is worthwhile for less than a 120 don't waste your money unless you have a specific reason for doing so.

joshua.jebe
03/11/2014, 11:30 AM
a 4ft 120gal tank or smaller tank on a good built stand should not be an issue

jonwright
03/11/2014, 11:45 AM
Confirm your joists match what's expected (10-12", @16" on center). If different (like in MY house) consider heavily.

My NEW construction on my house we loaded up three pallets of stone for a fireplace, all that weight basically sits on the floor. No one was worried about the weight. So do the math, that's easily 6,000 pounds (we have 30' ceiling). We used 16" engineered I joists, folks assured me I could park my truck in the LR with no issues.

If your tank is outside wall (which bears weight) and placed perpendicular to joists certainly a 75 would be fine.

My OLD house was built with 2x6 joists (WHAT???). I live in rural Arkansas. we have no codes. None. The floor bounces when my dog walks across it.

I WOULD NOT put a 75 in my old house floor.

Structural engineers, especially around here, specialize mostly in commercial buildings because residential building really done require it. A residential architect can probably yak with you on the phone and allay your fears I'll bet.

Besides, you'd likely see sagging way before the floor gives way methinks. :D

But hey. It's your pad, call someone if it makes you feel better.

Or do this - have 4 well-built friends over, have them hug where your tank will be. If your floor doesn't fall through you are probably OK.

Despairodyne
03/11/2014, 05:05 PM
Nice to see this topic come up. I wish to put a 95 gallon tank against a load bearing wall parallel to the joists. One end of the tank is against an
outside wall. My plan was to sister the joists that are within four feet(on both sides) of the load bearing wall. Then put an engineered beam perpendicular to the sistered joints, and put a lolly column under the load bearing wall joist and one on each end of engineered beam. The perpendicular beam would be 5 feet from the foundation.

Then I realized that my 60 year old hardwood floor might crack or at least sag a good bit. So, I could remove the hardwood floor where the stand will be and reenforce it with a rigid base. Then move my stuff out of the house because, you know, married and all that.

Or just do a nano tank.

airtime23
03/11/2014, 05:06 PM
Consult a structural engineer.

ca1ore
03/11/2014, 05:40 PM
Check this out. Was one of the more useful articles I read when considering the weight of my tank. Also contains a number of myths, a couple of which have already been offered in this thread :)

http://badmanstropicalfish.com/articles/article28.html

OutsideBrian
03/15/2014, 02:42 PM
Does anyone know of a calculator that you input lumber dimensions to get a carrying load of that piece of wood?
IE A 2x8 14 feet long made of pine can hold X pounds?

DaveWJunior
03/15/2014, 04:05 PM
I believe lowes.com used to have a deck building link that woukd give you a live load rating for a deck as you "built it" online.

SGT_York
03/15/2014, 07:24 PM
Outside Brian,

It's far more complicated than just that, one board won't hold much because they will twist and snap under a bit of weight but several boards together with perpendicular boards that prevent the boards from twisting will hold far more weight than three individual boards. Also the plywood top makes a large difference, and where that weight is on the board, moment bending in the middle, or shear where the wood is crushed or cut under the weight.

As a note to previous comments if you are rural anywhere (code didn't apply when the house was built) get an engineer.

sammy77
03/16/2014, 09:30 AM
I went thru this a couple years ago before placing my 220gal in my living room. Kudos to you for doing your homework first.

I asked a couple carpenter friends I have for their opinion, then called a structural engineer and he gave me his thoughts for $100..lol He suggested less of an approach to support the weight then the carpenters did.

Anyways, this is how it turned out:

http://reefcentral.com/forums/showthread.php?t=2141574

OutsideBrian
03/16/2014, 02:43 PM
I realize there are more complicated factors involved. I was just wondering about the actual piece of wood and it's potential. Take out the twisting factor.
This is my townhouse. My tank would be parallel with 2x8 joists 14' long and 12" center. The outside wall end of the joist is on concrete foundation, the inside end is supported at 14' by 3-2x8 and again at 17' with another 3-2x8. The subfloor is 1/2 ply.
The back of the wall is against a concrete fire wall separating me and my neighbor.
http://img.tapatalk.com/d/14/03/17/syqydu2a.jpgDt room
http://img.tapatalk.com/d/14/03/17/ytubyryb.jpg
http://img.tapatalk.com/d/14/03/17/y3a4epu3.jpgthere is a gap between the concrete fire wall and first joist. the green room in the back is under the Dt grey wall. Both of the beams are the 2x8 beams carrying the joists.
http://img.tapatalk.com/d/14/03/17/8y2ygugu.jpg
Here is an idea of what a nun finished basement room has.
http://img.tapatalk.com/d/14/03/17/nagejybe.jpg
This is the outside end of how the joists are on the foundation.
http://img.tapatalk.com/d/14/03/17/ytatepu8.jpg
This is one of the headers 3 2x8

Now the stand I want to make would center on the grey wall. I want it to be 13' long, the center 5' to be 30" deep and the outside 4' to be 16" deep.

Will a 125 gallon tank be realistic?

OutsideBrian
03/16/2014, 03:51 PM
My last post did not come through?
I found this https://courses.cit.cornell.edu/arch264/calculators/example8.1/

OutsideBrian
03/16/2014, 04:48 PM
Here is my scenario.
I want to put a tank on the gray wall. But the stand will be 13' long. The outside ends will be 16" deep and the center 24". I want the tank in the center. I am thinking the center section will be five feet long leaving the ends 4'.
Behind the grey and green walls is a concrete block fire wall.
My floor joists are parallel to the stand / wall and are 2x8 at 12" spacing.

http://img.tapatalk.com/d/14/03/17/emeza6av.jpg
http://img.tapatalk.com/d/14/03/17/uzytymen.jpg
http://img.tapatalk.com/d/14/03/17/a4e5e7ur.jpg

The outside wall end of the joist is on my concrete foundation. Here is an example from an unfinished area.
http://img.tapatalk.com/d/14/03/17/ze5e8epy.jpg
http://img.tapatalk.com/d/14/03/17/jupe4yzy.jpg

The interior end of the joist is supported by three 2x8's at minimum of 14' and max of 17'. I cannot tell without tearing out some drywall.
Here is an example from the unfinished area.
http://img.tapatalk.com/d/14/03/17/uqajy5ys.jpg
The sub floor is 1/2 plywood.

I am looking for opinions on safe tank sizing. I am thinking about 75-150.