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Reinforce floor for 180, floor jacks from HD?

10K views 21 replies 9 participants last post by  Psyduck 
#1 ·
Ok I'm about a week away from filling up this 180 gal tank I have. I've chatted in previous threads about doubling up joists for reinforcement, but am not sure I really know what I'm doing when it comes to that. What about using floor jack from Home Depot (found them in their online store, $25)? They looks like metal jacks that can extend as high as 9', which should be fine for placing a 4x4 parallel to the tank to give it added support. Is this a stupid way of thinking and it would just be easier to nail additional joists to the current ones or is this an even better way to take the bounce out. Thanks.
 
#5 ·
By floor jacks if you mean the screw type you can get simple pyramid blocks like you would build a deck with and put them under your floor. They are cheaper than the screw type. You simply cut a 4x4 to the right length and lag bolt it in to the block and then to the bottom of the floor joist. JMO

Jeff
 
#6 ·
It kinda depends what the material is under the house. Beneath my subflooring is dirt. The floor jacks are wooden 4x4 with a 9' diameter concrete footing. you plumb the jack under the floor joist, then tie the jack to the joist using a galvanized joint which joins 4x4 with 1 3/4(depending on width of floor joist). Do a 4 or 6 pack of these then crosstie the floor jacks together using 2x4s. That should make the floor nice and stable.
 
#10 ·
I know this thread is almost a week old, but I was on a nice vacation and relaxing for the last week in South Carolina, so I haven't been on here in over a week.

Psyduck: Did you purchase the floor jacks? Are you done with supporting the floor?

If you did do this i would be curious on how you tied the floor into the jacks, that can be difficult.

Well from what I have been told the worry isnt it falling through the floor it is bounce in the floor. Do you have any noticable bounce around your tank?
Well to respond to this, i would say that 'bounce' or vibration in the floor will be dampened by the weight of the tank on those joists. Bounce isn't really what you should be concerned about, deflection is more of a concern. if the floor deflects under the weight of the tank you might notice a slight 'down hill' walk to the tank. Deflection may not be a concern depending on where the tank is located though. Deflection will be its greatest if the tank is in the middle of the joists, and much less if it is by a support of the joists. I dont remember if we discussed this previously or not.

Let me know if you need any more help on this subject, I am always glad to help.

-James
 
#11 ·
Sorry I was out of town for the weekend too :). No I have not bought the posts yet, we have postponed the setup for a few weeks yet do to problems with getting my parents here. As far as attaching them to the floor, I guess I thought it would be fine on its own after I tightened it and attached it to the joists/2x4s. Perhaps this was naive (spelling) on my part. This is a partially finished basement so there is a thin carpeting on the floor.

I see your point about the deflection/bounce, that is what I am concerned about. I was just trying to find a nice, easy, cheap way to give myself a little piece of mind and I thought the floor jacks would be it. Again I am not the greatest at DIY Home Improvement stuff, but if you have other ideas I would be open to them :). Thanks!
 
#12 ·
How many floor joists were you intending on using?
one per joist? that seems expensive and overkill.

If peace of mind is what you are looking for then you might want to look into running a 4x4 or similar across the joists in question and then run the floor jacks to each end of the 4x4, but that depends on which direction were your floor joists are running.

I kind of need a better picture in mind to help you further.

HTH - James
 
#13 ·
That is exactly what I was planning. Actually the tank will be on an angle to the joists, and will probably cover 3-4 joists. My plan was to use a 4x4 directly under the tank and use 2 of the floor jacks as support. Hope this gives a better picture of what I want to do :).
 
#15 ·
Ok when you say "doubling", you are just jamming in another 1x6 right next to the current ones and running them over the load bearing parts that the current ones are over? I guess I'm not exactly sure what "doubling" entales.
 
#16 ·
well first it wouldnt be a 1x6, it is probably a 2x6. a 2x6 dimensions are not 2"x6" that would be to easy:rolleyes:
A 2x6 dimensions are 1.5" x 5.5"

anyway you would 'sister' or 'double' the joist by placing the new joist of equal length directly next to the existing joist to create 2 joists so instead of the floor system looking like this

| | | it would look like this || || ||

you would do this under all of the joists that you need to reinforce. you should attach these joists together so they work as one joist. make sure that the new joists run the full length of the existing joist and properly attach them to the bearing points.

Let me know if you have any other questions or if i didnt explain this clearly. I kind of just put the basics on here because i am short on time right now.

HTH - James
 
#17 ·
No I think I understand what you are saying. Actually I think one of the joists is already doubled up so I will follow that template and go by that. Thanks, I will post more questions if they come up.
 
#18 ·
I sware I hate having a paranoid personallity. So we finally lifted this huge thing onto the stand last night, and the floor already has a bounce to it, and it doesnt even have any water in it? I guess when I say bounce, I mean if I shift my weight up and down like I am jumping without leaving hte floor, the tank shakes. I cant imagine what it will do with water in it! On a side note, I did look to see about just nailing a 2nd joist in parallel to the ones currently there, as suggested earlier. Only problem is the stupid heating ducts, they seem to make things difficult in that area. Well this is the weekend of total setup, so I may be back for more paranoid questions.
 
#19 ·
I recently set up a 180 in the livingroom of my split level house. Though I probably didn't have to, I used two of the floor jacks anyway. One under each joists on the ends of the tank.

It should work just fine for you. I was going to have the jacks hold up a 4x4 under the span of the joists as well but when I got down there to do it, the jacks were too tall without even being extended to fit the jacks and the board.

Every house or apt I have been in and had a tank had some sort of tank bounce. I used to have two 75 gallons about 5 feet across from eachother in a second floor apt. Both were packed with live rock and sand and only one was on a load bearing wall. The other was simply against the stairway wall pratically in the middle of the room.

I would just use the jack and fill the tank. I wouldn't worry too much. BTW my 180 has something like 700lbs of sand plus the water and rock.

Good luck!
 
#20 ·
I found adjustable cement pillars (you know, the pyramid shaped concrete foundation posts) that attach to a 4X4 or 6x6 vertical cut about 6 inches short of the joist, that I place under another perpedicular 4x4 that runs across 2-3 joists....you adjust the pillar post with a giant screw until the 4x4 just touches the joists....then you tap hard wedges btwn the cross piece and all 3-4 joists. No bounce, tons of strength. But your situation may be different.

HTH, Mike
 
#21 ·
semajftw said:
I know this thread is almost a week old, but I was on a nice vacation and relaxing for the last week in South Carolina, so I haven't been on here in over a week...
James, I canno believe you were here and didn't come by to see the setups...

On the floor jacks, they work great, especially if you alreacy have footings (the concrete floor) in place. I used the same setup for both big tanks and the floor is rock steady. btw, you don't need to actually jack the floor up, you only want to make the jacks fit firmly under the beam you put in place. Jacking up the floor may result in cracking the wall plaster/drywall. Although you can correct for slope in the floor, it is not recommended by most ontractors unless the slope is escessive, and then it would be better to correct the deficiency rather than to correct for this by jacking the floor.

Ought to be worth 2cents...
 
#22 ·
**** this setting up of the new 180 is harder than I thought (well not really but **** it is a pain). We could not just reinforce the floor with wood so we went with 2, HD floor jacks (or as someone said, supports). They seem to be holding well and I did not really "jack the floor" up I dont think, I just made them rock solid tight. I think it may have lifted up the joists a bit, but nothing severe. The tank is half full (with new water, other half will be from my current 90 gal). I filled it with 250 lbs of HD/Quickrete white sand (the rest again will be sand from my current tank). So far no major disasters, I will be sure to take a pic once everything is moved. Thanks for all the help on the floor.
 
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