Floor Joist Support Help

[ChimolaFish]

Hey, guys (and gals),

So I'm almost ready to fill my 90RR with 20L sump up finally. I'm just waiting for the baffles to cure completely. Anyway, I live in an apartment 1st floor, but the basement sits below me. So I'm a little worried about the weight since I can't run the aquarium perpendicular to the floor joists. As it sits, the aquarium will be on an exterior wall and supported by two joists (one of which is the middle one in the picture and the other is the far right one that sits on concrete. I added these two poles that my dad made and I'm thinking about adding another one just to be safe.

What do you guys think about the floor/weight/etc? I've read all the info out there so I know you can't be sure without a contractor. And typically aquariums up to 125g you usually don't need to worry about if they are on load bearing walls and perpendicular to joists, but mine obviously isn't perpendicular. My dad says it should be fine and he's a contractor, but although I trust him, I'm not sure if he realizes how much an aquarium this size can weigh. Also, do you think these supports are ok, or is something very dangerous about them?

Thanks!

 

[ChimolaFish]

Maybe I'm in the wrong area? I figured DIY for a solution to a floor bracing problem...

 

[M_Jaco]

I wouldn't worry. especially if one of the joists is bearing on the concrete wall below it. the other joist should be able to take up the remaining 1/2 of the load(assuming the tank is centered there) even without those extra supports

 

[Mules1]

I'm not sure from the pics where the tank is sitting but I can tell you this: the "jack" posts that you have there sitting on a piece of wood on loose soil in a damp Ohio basement isn't supporting anything.

 

[zachts]

I'm no structural engineer but diagonal boards drastically reduce the bearing capacity on a deck, what's on top of those upstairs? I've not seen pine boards ever run on a diagonal like that in a house. I'd be nervous too from what I can see in those pictures. normally to do that for decorative reasons you space the joists really close, like 12 or 14" on center. those look to be more than 18" apart.

I would consider finding a professional to consult. Or at least your land lord.......

...........wouldn't be a fun phone call to tell the land lord your tank is now in the basement............

 

[ca1ore]

Figure your tank will weigh somewhere in the vicinity of 1,200 pounds all in. That's 600 lbs supported by each joist. One is supported by a retaining wall, so no problem. The other by a dual jack posted beam. Commercial jack posts can handle something like 9,000 pounds each, so as long as the ones your dad made are robust, and you have a reasonable plate on the floor, I think you will have absolutely no problem.

 

[ChimolaFish]

Mixed replies... GREAT, haha.

Zachts, the diagonal boards aren't the flooring. I have a completely different floor upstairs. How does that reduce the bearing capacity? I thought it might help since it redistributes some of the weight to other joists.

And I know it looks like soil under the wood, but it's actually concrete with a thin layer of dirt on top.

Any thoughts on how I could brace the beam better?

 

[ChimolaFish]

:uhoh3: Ugh, I just read an article about how older houses (which a lot of people say are stronger in a lot of ways) mount their joists to the exterior walls sometimes. This is how that one joist hits the wall. It looks like it's just nailed into the side. So I guess my new question is whether I can just place one of those pipes very close to the edge and use three spread out evenly across the load of the tank. Or some sort of lam beam. Or do you think it's a lost cause? I just finished getting all of the equipment and won't be moving for another 2 years. Ugh.

 

[ca1ore]

Look, I'm a charter member of overbuilders anonymous, and I'd not hesitate. As long as there is direct vertical support under each corner of the tank, doesn't matter how the beams connect at the end. I have a 265 (FAR heavier) supported by a retaining wall directly under the floor joists towards one end and dual jack posts under both corners on the other end (supporting about 1/10th of capacity). I also have my tank oriented along rather than across two beams. No problems. FWIW, a 90 simply isn't that big; so just move the two jack posts so that they sit under the two corners of the tank.

About the only other thing I'd do if I were you is run some wood blocking between the two joists to prevent them from twisting. Nothing's guaranteed in this world, and you might collapse your floor, but I highly doubt it.

 

[ChimolaFish]

Look, I'm a charter member of overbuilders anonymous, and I'd not hesitate. As long as there is direct vertical support under each corner of the tank, doesn't matter how the beams connect at the end. I have a 265 (FAR heavier) supported by a retaining wall directly under the floor joists towards one end and dual jack posts under both corners on the other end (supporting about 1/10th of capacity). I also have my tank oriented along rather than across two beams. No problems. FWIW, a 90 simply isn't that big; so just move the two jack posts so that they sit under the two corners of the tank.

About the only other thing I'd do if I were you is run some wood blocking between the two joists to prevent them from twisting. Nothing's guaranteed in this world, and you might collapse your floor, but I highly doubt it.

Ok, that gives me a little piece of mind. I think I'll add one jack real close to the wall where the joist meets the wall, then space the three others evenly out on the cornes of the tank. I wasn't going to worry too much about it (until I saw how the thing met the wall :eek2: ) except for the fact that my sump will add another hundred pounds or so, and I'm using a little more rock than is needed for the aquascaping I need.

 

[jonwright]

Let er rip

Let er rip

So have you had guests over? So that's roughly 6 full sized Americans (not Europeans).

Check your joists before having company? Most folks don't.

So if your floor does fall through then I'd say its beyond just under or poorly built.

Now if you were asking about a 180 gallon or up that's a different story.

 

[ChimolaFish]

So have you had guests over? So that's roughly 6 full sized Americans (not Europeans).

Check your joists before having company? Most folks don't.

So if your floor does fall through then I'd say its beyond just under or poorly built.

Now if you were asking about a 180 gallon or up that's a different story.

Well that's live weight vs dead weight, plus I usually don't have everyone standing in a 18"x48" box. But I get what you mean.

 

[jonwright]

Right. Technically not the same but to keep perspective in order.

 

[ChimolaFish]

Well I think I'm going to test fill it tonight with sand rock and everything and hopefully I can get on and tell you all the good news.

 

[zachts]

Mixed replies... GREAT, haha.

Zachts, the diagonal boards aren't the flooring. I have a completely different floor upstairs. How does that reduce the bearing capacity? I thought it might help since it redistributes some of the weight to other joists.

And I know it looks like soil under the wood, but it's actually concrete with a thin layer of dirt on top.

Any thoughts on how I could brace the beam better?

Depends on the flooring upstairs, if hardwood then don't worry about it. If vinyl or pergo or such composit stuff then it does, the boards are then spaning a wider distance than if they were perpendicular to the joists as most homes are constructted. It is very wierd to see sub floor run on the diagonal like that.

diagonal subfloor means it is weaker at the foundation wall also.

 

[ChimolaFish]

So I added two more of those pipes and filled the tank. So far so good

Now I need to see if it'll stay that way.

 

[hllywd]

Depends on the flooring upstairs, if hardwood then don't worry about it. If vinyl or pergo or such composit stuff then it does, the boards are then spaning a wider distance than if they were perpendicular to the joists as most homes are constructted. It is very wierd to see sub floor run on the diagonal like that.

diagonal subfloor means it is weaker at the foundation wall also.

Actually almost every home in this area old enough to have boards for the subfloor have them running on the diagonal. Never gave it much thought, but always assumed it helped keep the floor system from racking making the floor system more rigid. I've never built anything that didn't have a plywood, or OSB subfloor. Finished floor T&G hardwood will run perpendicular to the joists on top of those boards for houses built up into '60s for the most part. In almost all cases there is another layer on top whether substrate for tile, carpet, etc... I would say I've never seen a finished floor directly on top of the diagonal subfloor boards. Here at least, that was the way it was done prior to plywood. Here in Ohio the diagonal boards in home prior to the advent of plywood are perfectly normal.

 

[ChimolaFish]

^what he said

 

[zachts]

^what he said

Interesting, I guess that's just how they did things back then, Iowa and Missouri I've never seen them on the diagonal.

 

[NanoReefWanabe]

my house also has diagonal boards for the subfloor..as well as 1x6 rafters…LOL

anyway…i would say grab a joist hanger and a box of N10 nails and hang that joist a little better on the rim board there…i would assume the jack posts are more then overkill for a 90 as well…but for piece of mind it is better then the tank in the basement…those joists also look to be 2x10 or 2x12? and that is old wood so those are actual dimensions and not the nominal crap we have now…i would say you are fine…buti would throw a hanger in there anyway.