Any structural engineers out there?

Please read what I wrote, not what you read. I did not compare OSB to an engineered joist I said it was part of an engineered joist for a reason, when kept in a straight line with 2x4flanges it is extremely rigid.

What the he** is going on here. Adjusting for species of wood, while needing a huge factor of safety? Um, Ok.

Look, bottom line is you have minimal deflection under your fully loaded tank. You have (apparently) sistered the joists. My recommendation is to not listen to anything but common sense on this. Species of wood matters not. Really, the OSB matters not. If you have what you say you have then you could reasonably park an elephant in there to admire the fish and your floor is not going to collaspe.

I mean, really? Yes, floors are "designed" with a typical dead load of 20 to 40 psf (over the entire floor) and he has way more than that in a small area. It's all going to fall apart! Actuallly, no you are just fine. Am I going to stamp this? Probably not, unless you want to pay me money and live in one of the right states.

I lied...I didn't stay away, Blocking per sketch mithesaint!

Edit...I would love to see a picture of your aquarium...Sounds awsome!

Joist hangers, not toenails for the blocking right?

If you stagger them, you can screw or nail right through the joist into the block.

Not so easy if the joists are doubled already.

Joist hangers would be great, but I would just toenail them.

Still hoping for some pictures.

I read some posts and have to think..............I know joist hangars are better / stronger but why? how important are they really.......
are they better because people are forced to use them and must nail every hole, meaning they have to be used correctly?? and can be easily visually inspected
as opposed to proper end nailing or toe nailing which could be easily short cut by leaving nails out, incorrect nail spacing??
houses that have stood for hundred plus years do not have one joist hangar in them....
so is it maybe the true craftsmanship, deisire to do it right, of years past,
even some old buildings which are outdated seem to be better than what we build now.
my opinion is not many people left have been taught to do it correctly, some of the ones taught correctly just do not do it for ease and speed
and the rest just do not care, get it done make a buck move on......

Joist hangers force a consistent nailing pattern and number of nails and end bearing to properly support the weights expected.

The only shortcoming is that people get away with using incorrect nails as the inspectors appear to only see the fact the hole was filled (if even that, this could become a very long topic).

My favorite are the builders that just blast through the hanger with a nail gun, they do make a cool nail gun that exposes the tip of the nail so you can align it with the hole in the hanger.

Totally agree with IP and Smokey's points!

My favorite are the builders that just blast through the hanger with a nail gun,






I've been doing it that way for 20 years........young whipersnapper

Probably older than you IP, Best way for me is to use a palm nailer!

I used the old fashioned hammer when I hung a few this past summer, it survived its first 'quake so I must have gotten them all where they should be. If the information I found was close to being correct my joists aren't in any danger of dropping down due to weight issues at the joints. Joist defection is a different matter entirely. They won't be bowing left or right either because it is blocked.

I hates decking that is a bouncy house.

Yes the lumber flanges are there for nailing and to keep the OSB from bowing. They do minimal in terms of the acutal load capacity of the TGI.

What's a TGI...Do you guys mean TJI or am I unaware as usual??

quote="Eatonpcat, post: 1220415, member: 18117"]Probably older than you IP, Best way for me is to use a palm nailer![/quote]

was not aimed at you Eatoncat, I was refering to what the guys that do that say. I am guessing we are close in age based on knowledge and commenting, maturity.

thank you.

according to WIKI they are interchangable but TJI is the correct term.

Again, many thanks for all the advice.

Sorry for the delay, but a full time job/on call duties/2 small kids/life in general got in the way.

Back to the project. Blocking sounds nice, but the joist spaces that would be blocked are filled with heating ducts. I think I'm going to install a 3rd extra 2x10 and call it quits. That should cover the extra load for when my fat friends come to visit

Final question (probably not, but maybe): Which joist would you sister the 3rd 2x10 against? The joist that's closer to the wall that the aquarium will rest against, or the joist out further away? I'm leaning for the joist further away, but just wanted to make sure.

Thanks.

Pics will come at completion. Empty aquariums are boring.