Floor support advice.....

8 bags of concrete is like 25$
8' PT 6x6 is like 15-20$
3 8' 2x10 is another 24 or so bucks"¦
a handful of 4" spiral construction nails is about 2.50$
and a tube a couple tubes of PL premium is going to be about 20 bucks"¦

so with tax you might be over 100$ sorry"¦

you might want to throw in a couple hangers too to tie the posts to the beam they are about 1 each"¦


no need to ask an engineer what the beams and joists are"¦go down and look at them"¦LVL looks like sheets of plywood glued together, parallam looks like strands of wood glued together"¦N10 nails are structural nails specifically used for hanging joists in structural floors and they are clearly marked on the heads for the inspectors to see"¦though i would not trust a single LVL to hold up a floor a couple of them glued and screwed to one and other is a different story"¦if there is a couple glued and screwed and the joist hangers are nailed in with N10's and all the nails are there and everything is doubled up like it was supposed to be great"¦would i trust it not to sag over time to hold a tank and onlookers"¦i would still spend the 100$ and add a mid point support.

I hadn't looked at the actual costs of doing things so I guess it wouldn't be that expensive to add some additional protection. It has been raining for 3 days straight here so I didn't get to go under the house this weekend. I will try and do it tomorrow after work. Based on your description of parallam/lvl I think they used paralams and they are doubled up. Since I am in a new development there a lot of houses being built around me so I will see if I can get a picture of one that is sitting on a job site.
 
I am an engineer (structures) and i'm not going to tell you for certain wether or not the floor will hold, but by looking up some charts online, and using the dimensions you gave earlier in the post, it seems it will be OK(I wouldnt worry personally).

you would be correct in thinking that simply putting piers under the tank wouldnt do much. such as the "solution" in radobahn's post, if the floor were to fail, depending on the soil type and the footprint of those blocks, they could just settle into the ground without much resistance. Then again they could be fine... it really comes down to soil type and bearing pressure(Force/area)

it is more likely that the reason the contractor hasnt given you an exact capacity for the section, is because if they have an in-house engineer, they have more important things to work on, or if they used a consultant, that consultant has more important things to work on. I work with contractors and their engineers on a daily basis and sometimes it can take a while for seemingly simple calculations or analysis to get back.
 
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Ok...so I spoke with the builder today and was told that they use two lvl's that are glued and screwed together and N10 nails. He understands my concerns about the waiver and said that it was mostly their legal department that wants me to sign because they have never dealt with adding additional support for a fish tank. They have done it for safes, gun safes and pianos but never a fish tank. He says I don't need any additional support but if its only going to cost a couple of hundred then it might be worth it just for the additional peace of mind.
 
Yes. I have two large tanks and supported the floor just in case. Probably not needed, but the consequences are extreme and the cost was low.
 
Yes. I have two large tanks and supported the floor just in case. Probably not needed, but the consequences are extreme and the cost was low.

If something like that every happened I would have to go into hiding....my wife would kill me!!! I will be doing this soon before it gets too hot down here.
 
If something like that every happened I would have to go into hiding....my wife would kill me!!! I will be doing this soon before it gets too hot down here.

Maybe, while you're at it, you should build a little air conditioned 'fort' down there to hide in... Just in case!
:eek1:
 
He says I don't need any additional support but if its only going to cost a couple of hundred then it might be worth it just for the additional peace of mind.

Yes. I have two large tanks and supported the floor just in case. Probably not needed, but the consequences are extreme and the cost was low.


Same reason I spent the time and money to support the floor under my tank. I was told I didn't need any extra support and that what I did was overkill.. and I'm perfectly fine with that :)
 
Ok...so I spoke with the builder today and was told that they use two lvl's that are glued and screwed together and N10 nails. He understands my concerns about the waiver and said that it was mostly their legal department that wants me to sign because they have never dealt with adding additional support for a fish tank. They have done it for safes, gun safes and pianos but never a fish tank. He says I don't need any additional support but if its only going to cost a couple of hundred then it might be worth it just for the additional peace of mind.

this is a little more assuring"¦.that said for the 1/100th it will cost to build this tank i would like a little more peace of mind"¦

hopefully it is native undisturbed soil in your crawl space and you don't have to do too much digging...
 
this is a little more assuring"¦.that said for the 1/100th it will cost to build this tank i would like a little more peace of mind"¦



hopefully it is native undisturbed soil in your crawl space and you don't have to do too much digging...


Unfortunately we have very dense clay filled soil so it will take a little extra effort to dig but not too hard to do.
 
Unfortunately we have very dense clay filled soil so it will take a little extra effort to dig but not too hard to do.

clay don't matter if it is not wet or exposed to freezing, high water table will also be a bad thing"¦you just don't want topsoil, loose (excavatored) soil/ backfill of any type, wet gooey clay, or loam. sand, gravel, clay are my preferred soils to build on...
 
clay don't matter if it is not wet or exposed to freezing, high water table will also be a bad thing"¦you just don't want topsoil, loose (excavatored) soil/ backfill of any type, wet gooey clay, or loam. sand, gravel, clay are my preferred soils to build on...

Im trying to figure out how deep I want to dig for the footings. I was thinking 12"
 
Ok now that I have decided to add the additional support my next question is where the support should be with relation to the tank. The far edge of the tank will be 42" from the wall. Should I put the supports right at 42" or go in a little and make them at say 36" ???
 
Im trying to figure out how deep I want to dig for the footings. I was thinking 12"

use the quikrete specially made for post holes, no mixing just pour it in and add water. it set up super quick for my deck posts, first thing I thought of is how easy it would make setting posts for a fish tank
 
use the quikrete specially made for post holes, no mixing just pour it in and add water. it set up super quick for my deck posts, first thing I thought of is how easy it would make setting posts for a fish tank

that is not the cement mix i would use"¦i would likely use quickcrete contractor grade concrete"¦if you are going to hand mix it"¦if you are doing 6" posts i would do 16" square pad 12" deep"¦you could likely get away with 8" but"¦an extra bag or two won't kill you.
 
Lowes carries floor joist support jacks. You can use these to support your floor. also you will need a 18x18 stepping stone to put under them. I also used a 2x6 the length of my tank. What this does is distribute the weight evenly over multiple floor joists.
 
clay don't matter if it is not wet or exposed to freezing, high water table will also be a bad thing"¦you just don't want topsoil, loose (excavatored) soil/ backfill of any type, wet gooey clay, or loam. sand, gravel, clay are my preferred soils to build on...


interesting you say clay is your favorite soil to build on... clay is the reason the Tower of Pisa is famously leaning!
 
Im trying to figure out how deep I want to dig for the footings. I was thinking 12"

since you're located in south carolina, it doesn't really matter how deep you dig your footings due to there being no frost line (not normally at least). Ideally you could pre-consolidate your soil by placing weights onto the area where the footings will go. the longer you can leave the weight there the better. for a quick way to do this just divide the weight of your tank by the # of footings you plan to use, and place that weight over each proposed footing location.
 
i don't think the clay was the reason for the lean…the soil was in adequate for building on and was not amended or removed prior to building…everything i have ever read on the tower states its soil base consisted of clay, silt, and sea shells…none the less….he is not trying to build a tower nor is his structure likely to see any weight…it should only be built in place to catch the floor, not support it…applying an upward force on the floor would be a bad idea, however preventing the floor from deflecting won't harm the floor…

another thing that can be added to the joists is more plywood to fill the web spacing as the builder has already done to a portion of the joists...
 
Support for crawspace

Support for crawspace

Hey I have a 220 display with a 75 gal sump in the middle of our great room above a crawlspace. I initially added 8 extra joists in the area underneath or close to underneath the tank which was more than adequate to hold the weight. The issue isn't with holding the weight but with keeping the tank solid. With just the joists if I jumped up and down near the tank (gently) it would eventually rock back and forth (not good). I ended up with 6 steel floor jacks supporting 2 12 foot 6x6's supporting the entire floor to stop the issue. Yes it's overkill but I have never regretted it. We have a concrete floor in the crawlspace and I still spread the weight out through 2x12's with shims to level and 4' by 4' sheets of plywood. The last thing you want to worry about is the floor there's plenty of other problems to worry about :)
 
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