Need structural advice for potential aquarium

[fishguy242]

stalking ya now

 

[hikermike]

Would definately add beams under tank and use the lumber with larger scantlings. The increased cost of the larger lumber now pales in comparison to the increased peace of mind and upgrading later on. Are those joists on 12' centers? That usually is seen in commercial construction and 16" on center for home. This adds to load bearing ability. Get at least #2 grade lumber and not 3 or 4. The strongest would be Douglas fir and then southern YELLOW pine. Mid category is hemlock and weakest is WHITE pine. You could sneak in a few bags of rocks and concrete and mix in place in a sauna tube without anyone noticing.

 

[i_declare_bankruptcy]

12" from joist to joist if that' what you were asking. And I remeasured and they are indeed 2x10's. I think they're closer together because it's a rather long ~18ft run.

Do you guys think this strategy would hold up for a 180g as well (vs the 120g I'm eyeballing)? Same 72"x24" footprint, but 24" high instead of 17" high.

 

[fishguy242]

12" on center cool, yep 2 6x6 posts 4x8 beam 180 no problem,span the beam10' space the posts at 6' exactly where the 6' 180 will sit

 

[i_declare_bankruptcy]

I'm flopping on the size of tank I want. I'm also considering a reefer 250 or 350, which would be 65 or 91 gal respectively. Wondering if I would need to support the floor at all to hold the 250 (probably not), or if I could get away with the 350. Reasoning is that I think (as much as I don't want to admit) a smaller tank would look better in the room.

 

[i_declare_bankruptcy]

In other words, considering procrastinating on supporting the floors for when I want a bigger tank in the future, if I end up staying at this place for more than a few years.

 

[fishguy242]

what is weight on 350 empty,how many gals,will it be positioned across 12" joists or run length wise with them??

 

[kyleinpdx]

Personally, I think you are in a pretty good spot already given how many joists you cross and how much space you have to work with. It'll be crappy I know, (you know how? because I did the same thing in a crawlspace with 21" of clearance) but get down there, dig down 6-12", get a couple bags of quickcrete high strength, a bucket, a mixing paddle for your drill, 2-3 appropriately sized jackposts, and 4, 2x4's. Pour the concrete in the ditch you dug, let it cure fully. Take those 4, 2x4's and glue and screw them (or bolt them) together on the 4" side to make a 8" x 4" beam (ok so really like 6.5" by 3.5"). Place the jack posts on the concrete slab you laid, put the beam on the jack posts on the 8" side and adjust the jacks until snug. Fill the aquarium, measure deflection and adjust jack posts as necessary. We're not trying to lift the house here, IMO/IME all you are really needing to do here is take some of the deflection out of the floor. Outside of curing time for the slab, this will probably take you 2 days worth of work. I could only dream about having that much space to work with under the house, consider yourself lucky, many of us have had to do some form of the above in waaaay worse conditions.

 

[i_declare_bankruptcy]

what is weight on 350 empty,how many gals,will it be positioned across 12" joists or run length wise with them??

unsure then empty weight of that setup... I was figuring 900lbs fully loaded as a guess. It would be Perpendicular to joists (in the same spot as the drawing for the previous option). Both the 250 and 350 would place roughly 180lbs on each Joist.

 

[fishguy242]

crossing 3? i,agree dig go big

 

[Victor_C3]

Honestly, I think you should just go ahead and do the work required to support the tank you want to get.

If you’ve never done any sort of work like that before, it might seem daunting. However, once you do it, it’s really not that hard to do. Break it down into a couple of steps, watch a bunch of YouTube videos, get ready to do a bunch of trips to Lowe’s/Home Depot, brush up on your swear words, and you’ll get it done in a weekend or two.

When you’re done, you’ll have gained a bunch of knowledge for future projects around the house and you won’t be as afraid to tackle other home improvements in the future.

 

[i_declare_bankruptcy]

My fear around adding the supports is that the HOA will discover it and then make me remove it.... after I've committed to a big tank and thrown in all the $$$$$$$ that goes with having a larger tank. It would be a total loss. If I could place a smaller tank safely in that space I'd prefer it, especially since it would look more appropriate in the room anyways. I'm just exploring all my options right now

 

[kyleinpdx]

My fear around adding the supports is that the HOA will discover it and then make me remove it.... after I've committed to a big tank and thrown in all the $$$$$$$ that goes with having a larger tank. It would be a total loss. If I could place a smaller tank safely in that space I'd prefer it, especially since it would look more appropriate in the room anyways. I'm just exploring all my options right now

Forgive me if its been said, but what is this a house, townhouse, condo? Is the area in question a shared space? If its a single family home, even with a strict HOA, why would they be down there? I doubt they're going to perform random crawlspace inspection, much less have something in your CC&R's/bylaws they could fine/enforce upon you.

 

[i_declare_bankruptcy]

@kyleinpdx It's technically a condo; it's built on a hillside with one shared wall (to my left/right, not above/below) which explains my tall crawl space. CC&R's specifically state not to modify any of the load bearing structure without review from committee and the work must be completed by an approved contractor. You might ask why did I buy in such a not-fun area? The community is superb, the HOA does an excellent job maintaining the homes, and I can see the ocean while staying barely in my budget I'm sure I could fudge the rules but read below for my thoughts:

My fear around adding the supports is that the HOA will discover it and then make me remove it.... after I've committed to a big tank and thrown in all the $$$$$$$ that goes with having a larger tank. It would be a total loss. If I could place a smaller tank safely in that space I'd prefer it, especially since it would look more appropriate in the room anyways. I'm just exploring all my options right now.

Technically I can fit an 8' 200-300 gallon system in there... but it would be way inappropriate for the room size and my budget. I can always do this upgrade after I've lived in the place for a while.

I just bought and moved in. My home is on the schedule for a full repipe and engineers need to get under my unit to replace a beam in my neighbor's unit -- doubt they would tattle but if someone on the architecture board is with them they would know. It's hard to explain but to get to any of the neighboring units they have to go under mine and that support would be dead obvious, practically in the way. I don't think it would go over well if I just move into this place and get immediately busted lol!! I'm already keeping a sailboat in my garage which is against rules...

So I'm just trying to see if alternatives exist for the time being. And if not I'll suck it up and take the risk but at this moment I'd prefer not to. Not really anywhere else to put a tank unfortunately. I'm moving out of my apartment still and have a 40b there that just isn't adequate for me so I'm trying to upgrade quickly so I don't have to do extra tank transfers lol.

 

[i_declare_bankruptcy]

This is the wall the tank will go against (excuse the state of the wall I have a lot of drywall repairing to do all over the place)

This is the exterior of my unit. At the bottom of the slope you can see the entrance to the crawl space. My office / where the tank will go is directly over that slope. That entrance is how workers get underneath the units that are to the left of mine. The rooms on the bottom are slab on grade but they're bedrooms and a tank has no business being there

 

[kyleinpdx]

@kyleinpdx It's technically a condo; it's built on a hillside with one shared wall (to my left/right, not above/below) which explains my tall crawl space. CC&R's specifically state not to modify any of the load bearing structure without review from committee and the work must be completed by an approved contractor. You might ask why did I buy in such a not-fun area? The community is superb, the HOA does an excellent job maintaining the homes, and I can see the ocean while staying barely in my budget I'm sure I could fudge the rules but read below for my thoughts:

My fear around adding the supports is that the HOA will discover it and then make me remove it.... after I've committed to a big tank and thrown in all the $$$$$$$ that goes with having a larger tank. It would be a total loss. If I could place a smaller tank safely in that space I'd prefer it, especially since it would look more appropriate in the room anyways. I'm just exploring all my options right now.

Technically I can fit an 8' 200-300 gallon system in there... but it would be way inappropriate for the room size and my budget. I can always do this upgrade after I've lived in the place for a while.

I just bought and moved in. My home is on the schedule for a full repipe and engineers need to get under my unit to replace a beam in my neighbor's unit -- doubt they would tattle but if someone on the architecture board is with them they would know. It's hard to explain but to get to any of the neighboring units they have to go under mine and that support would be dead obvious, practically in the way. I don't think it would go over well if I just move into this place and get immediately busted lol!! I'm already keeping a sailboat in my garage which is against rules...

So I'm just trying to see if alternatives exist for the time being. And if not I'll suck it up and take the risk but at this moment I'd prefer not to. Not really anywhere else to put a tank unfortunately. I'm moving out of my apartment still and have a 40b there that just isn't adequate for me so I'm trying to upgrade quickly so I don't have to do extra tank transfers lol.

Well, then yes, forget everything I've said. There very well may be periodic inspections for the seismic riders for varies insurance policies on the building.

Given those details, I think if you are set on a large tank, the avenue I would use to approach your HOA board is: "the floors are bouncy and I'd like to have someone come in and shore them up." You might be able to get away with a contractor coming in to sister the joists and/or place some joist blocking. Both of those will net you significant additional strength. Neither of those requests would generate nearly the amount of suspicion as "I'd like to install concrete piers for a huge fish tank." Given the way the world is right now, I bet you could find someone to come on out decently quick to give you an estimate on the job. Get 3 estimates, licensed, bonded insured, all that. If you picked up a sweet beach view pad and think you'll stay there even for 5-10yrs, getting this done might well be worth the cost.

Or go with a smaller tank, but who wants to do that?

 

[i_declare_bankruptcy]

Well, then yes, forget everything I've said. There very well may be periodic inspections for the seismic riders for varies insurance policies on the building.

Given those details, I think if you are set on a large tank, the avenue I would use to approach your HOA board is: "the floors are bouncy and I'd like to have someone come in and shore them up." You might be able to get away with a contractor coming in to sister the joists and/or place some joist blocking. Both of those will net you significant additional strength. Neither of those requests would generate nearly the amount of suspicion as "I'd like to install concrete piers for a huge fish tank." Given the way the world is right now, I bet you could find someone to come on out decently quick to give you an estimate on the job. Get 3 estimates, licensed, bonded insured, all that. If you picked up a sweet beach view pad and think you'll stay there even for 5-10yrs, getting this done might well be worth the cost.

Or go with a smaller tank, but who wants to do that?

Thanks to you and @fishguy242 for the fantastic advice. I’m definitely going toconsider that — perhaps as a down the road option. Unsure yet Great points on the inspections — I hadbt thought of that and it would be a huge bummer!!

do you guys have any input on this floor strength for 600-900lbs? (Reefer 250-350). I know you can’t get an exact answer but I’m curious your opinions. It does look stout with 2x10s every 12” but the tank isn’t against a load bearing wall so I’m unsure what to make of it.

 

[kyleinpdx]

Thanks to you and @fishguy242 for the fantastic advice. I’m definitely going toconsider that — perhaps as a down the road option. Unsure yet Great points on the inspections — I hadbt thought of that and it would be a huge bummer!!

do you guys have any input on this floor strength for 600-900lbs? (Reefer 250-350). I know you can’t get an exact answer but I’m curious your opinions. It does look stout with 2x10s every 12” but the tank isn’t against a load bearing wall so I’m unsure what to make of it.

In my unprofessional opinion, you have less to worry about re: the tank falling through the floor, more so introducing unwanted bounciness or noticeable deflection near the tank. 600-800lbs is 3 fat dudes on a couch, it really isnt all that much if you are carrying it with a couple joists.

 

[i_declare_bankruptcy]

In my unprofessional opinion, you have less to worry about re: the tank falling through the floor, more so introducing unwanted bounciness or noticeable deflection near the tank. 600-800lbs is 3 fat dudes on a couch, it really isnt all that much if you are carrying it with a couple joists.

4' 900 lb tank would be carried across 5 8x10 joists, 3' 600lb tank would be carried across 4 8x10 joists. Didn't seem like a big deal to me but wasn't sure. I have a friend I can run it by with diagrams so I'm gonna do that just to be safe.

Thanks everyone will report back

 

[fishguy242]

cool sounds ok to me,have another idea,just woke give me a little while ,too shake my brain,be back