floor support

[Da Squid]

This is more of a structural question than a fish tank question...
I'm planning on putting a 55g tank in my second floor den. I've done all the research for it/planned it all out and would hate to switch to a smaller tank now. I'm concerned whether or not that kind of weight would be safe for a second floor.
I live in perhaps a 90 year old house. The boards creek a little when you walk on them but no more than any other house that age.
Does anyone have any exerience or know any stories to persuade/dissuade me from going through with this?

I keep thinking of the scene in the movie "Whats Eating Gilbert Grape?" where they find out teh fat lady is destroying the frame work of the second floor house. A 55g would be much heavier than your average fat lady

[jsoong]

A lot depends on what the 2nd floor is made of. If it is an attic conversion, I might be leery - since the attic was not meant to support a lot of weight originally. Otherwise, you need ot find out how the floor was constructed to get an idea of the weight bearing capacity, and also to properly locate the tank over a load bearing wall & across the joists.

A cautionary tale - My house, 60 yr old, piano ~1000lb on main floor ... floor sagged over 3/4" in the span of 6-9 months ..... Your tank may be 500-600lb, but you get the idea.

[Da Squid]

Thanks Jsoong. I know I saved a copy of my house appraisal though I'm not sure it will mention how the floor was constructed. The second floor is a legitimate second floor and not an attic conversion.

The room I hope to put it in is very small (barely bedroom size) so the odds of a 48" tank crossing a support beam are hopefully high. I wanted to keep it against an inside wall, that is, a wall separating two rooms rather than a room and the outside. I'll definatley keep an eye out for a sagging floor based on your story.

[cogburn]

be careful... by the time you see a sagging floor it might be too late... if your tank gets out of level more than 1/4 inch you might come home to 55 gal of water and dead fish on the floor... i think you should have a professional come in and look at that... remember... 8lbs per gallon of water... substrate... tank itself... you could very easily get close to 1000 lbs... my 180 with water, sand, everything is about 2500 lbs... so 55 could be half a ton... youre not talking about lil stresses here this is big business

[joe ringbloom]

if your house is 90 yrs old you should be fine i am a residential contractor. hoiuses that old were usally build with hardwoods not pines like today pine wood did not take off untill the housing boom after wwii you should be fine. plus flooring was usally done with lath like your walls would be in that old of a house so it makes it even stronger. house built before 1944 are the strongest built because they were not mass produced try driving a spike nail into the floor and see how hard it is to do and not bend the nail.

[Da Squid]

Thankyou for the informed opinions! The consequence being sleepless nights and hair loss, it will be worth it for me to get the house inspected. I just wanted to see if a 55 might come close or not and it sounds like I've got a good chance of success.

[Da Squid]

This may be old news for some of you, but I came across what seems to be an excellent article on the whole structure issue.

how large an aquarium can my floor support

[jsoong]

Yes, I came across that & it was a good article.

Just a reminder: He is talking only about wood floor & houses built using "western framing" method. You can't generalized the conclusions to other applications - eg. apartments, etc.

[skylark]

I had exactly the same issue, I put a 90 gallon on my floor in a spot where I had the same concern plus there was a 3/4 inch drop in a 48 inch area. I solved this by building a sub-base made out of plywood with cross bracing in relation to the floor joists. It was actually easier than I thought, simply cut some 2x4's laid them on the floor and used a level to mark them all off. Took the whole thing down to the local store and they did the long cuts for me. If the floor is all ready level there are excellent aquarium bases that disperse the weight better than simply 4 legs holding it up off the floor. As mentioned a 75 will weigh about as much as a piano. If anything it might be an excuse to go buy some power tools.