1347 Gal | Aquarium Stand Structure Design Inputs

[pancakes]

I wanted to pause my build to gather structure design ideas from fellow DIY hobbyist who already completed a similar size build.

The stand will be constructed from 2x6 material and 2x4s for the tank dimensions. The space below will be for a combo sump and Ultima set up.

The goal is to be able to support a max weight capacity of 20,400kg/44,969lbs.


5100L| 3048x1829x914mm | 5,100kg
1347 gal| 120x72x36in | 11,242 lbs

Thanks in advance.

 

[Blakewater]

To support a max compressive load capacity of 20,000kg youre cutting it close with only 9 2x6's for vertical support. I would at the very least double all of those up. Mainly in the corners. But I feel a solid 4x6 would be the better option. I believe one 2x6 is good for about 4-5,000lbs of compressive force. with only 9 that puts you exactly 45,000lbs. However, wood gets wed and wears over time. Keeping it at its max load is not advised.

Also, the other rim of the stand should be supported by a stud as well. Sister one that fits almost perfectly onto the existing studs to fill the gap. If theres even an eighth of an inch of room between the top/bottom rim and the board, shim it with composite shims (not wood, they will rot). If that outer rim sags it could cause a seam burst.

This is just me being a paranoid carpenter but Id put a cross joist diagonally on the top side as well to prevent moving/twisting as much as possible. While wood is very strong compressive-wise, the slightest wiggle on a high strain board can shift the direction of pressure and snap a board. More than likely won't happen but in the event of an earth quake you want to be sure.

 

[Blakewater]

Outer rim* not other

 

[Dalfrey86]

To support a max compressive load capacity of 20,000kg youre cutting it close with only 9 2x6's for vertical support. I would at the very least double all of those up. Mainly in the corners. But I feel a solid 4x6 would be the better option. I believe one 2x6 is good for about 4-5,000lbs of compressive force. with only 9 that puts you exactly 45,000lbs. However, wood gets wed and wears over time. Keeping it at its max load is not advised.

Also, the other rim of the stand should be supported by a stud as well. Sister one that fits almost perfectly onto the existing studs to fill the gap. If theres even an eighth of an inch of room between the top/bottom rim and the board, shim it with composite shims (not wood, they will rot). If that outer rim sags it could cause a seam burst.

This is just me being a paranoid carpenter but Id put a cross joist diagonally on the top side as well to prevent moving/twisting as much as possible. While wood is very strong compressive-wise, the slightest wiggle on a high strain board can shift the direction of pressure and snap a board. More than likely won't happen but in the event of an earth quake you want to be sure.

+1 this.
One additional comment would be the addition of laminating the face and sides of the stand in addition to adding more support.

Paranoia is a wonderful thing as I tend to overbuild to reduce issues later in life.

One question that comes to mind is the foundation where this setup will be going. Will it be a concrete floor? Is the floor post tension or pre tension concrete?

Wood is great at holding a static load, however there is technically movement in the load during water changes. While you will have a max load once the tank is filled, stocked, and scaped, it might be better to have more room for future changes.

 

[BIG-G]

I would do as suggested above and beef up the vertical support.
I would also like to point out that the horizontal boards are only attached from the side while they hold the vertical 2x6 in position they do nothing for actual support.
The addition of other vertical support placed underneath the horizontal will go a long way in adding strength.
I would also install some X bracing to prevent any shifting from side to side in both directions.
Edit:
So I pretty much second what Blakewater
said already.

 

[pancakes]

To support a max compressive load capacity of 20,000kg youre cutting it close with only 9 2x6's for vertical support. I would at the very least double all of those up. Mainly in the corners. But I feel a solid 4x6 would be the better option. I believe one 2x6 is good for about 4-5,000lbs of compressive force. with only 9 that puts you exactly 45,000lbs. However, wood gets wed and wears over time. Keeping it at its max load is not advised.

Also, the other rim of the stand should be supported by a stud as well. Sister one that fits almost perfectly onto the existing studs to fill the gap. If theres even an eighth of an inch of room between the top/bottom rim and the board, shim it with composite shims (not wood, they will rot). If that outer rim sags it could cause a seam burst.

This is just me being a paranoid carpenter but Id put a cross joist diagonally on the top side as well to prevent moving/twisting as much as possible. While wood is very strong compressive-wise, the slightest wiggle on a high strain board can shift the direction of pressure and snap a board. More than likely won't happen but in the event of an earth quake you want to be sure.

Appreciate the inputs. I went with the Home Depot Douglas fir 2x6x10 for $7.76 ea. I used the same model from DIY Kings: "HOW TO: Build an aquarium stand" (0:20 out of 10:41). I plan on adding more 2x6 or 4x6x8s ($14.57 ea.) for vertical support in the corners and center. I couldn't find a chart or site that referenced a 2x6 compression to be 4-5k lbs. However, I did find a general number of about 700lbs a 2x6 can support. Not sure if my 36 inches in height would qualify but if it does, that means about a qty of 64 pieces of 2x6s should answer the call of 45k lbs (x4 the original weight of 1347 gal = 11,243 lbs).

For horizontal support, I plan on either replicating what I did with the center brace and corners every 24 inches apart or just start laying across more 6foot 2x6 joist for the depth of the stand like Joey did on his video. Still need to piece together what would work best to not lose the space below for filtration and possibly another tank. I plan on using some sort of waterproofing like Polyurethane, Varnish, Kilz complete, etc. once the stand is complete before I move on to the tank build. Maybe consider shower pan liner at the base to climb 2-3 inches up as well.

Once the structure looks like it will cover the total weight and is water proofed, I can feel better to start what's next. Lay a 3/4 plywood sheet over, add an R-Tech foam insulation, then another 3/4 plywood sheet on top (if that is even of add value) before I start on the 2x4 tank frame.

 

[pancakes]

+1 this.
One additional comment would be the addition of laminating the face and sides of the stand in addition to adding more support.

Paranoia is a wonderful thing as I tend to overbuild to reduce issues later in life.

One question that comes to mind is the foundation where this setup will be going. Will it be a concrete floor? Is the floor post tension or pre tension concrete?

Wood is great at holding a static load, however there is technically movement in the load during water changes. While you will have a max load once the tank is filled, stocked, and scaped, it might be better to have more room for future changes.

"Paranoia is a wonderful thing as I tend to overbuild to reduce issues later in life." --> So agree.

When you say laminate, you mean coating the wood all around, inside, and top to bottom for waterproofing I am assuming?

This will be on concrete. House is pretty new and I remember some patches in the perimeter of the home that may indicate the end of post tensioning cables. Yes, I compensated for the space I will need around the dimensions.

 

[pancakes]

Also, the other rim of the stand should be supported by a stud as well. Sister one that fits almost perfectly onto the existing studs to fill the gap. If theres even an eighth of an inch of room between the top/bottom rim and the board, shim it with composite shims (not wood, they will rot). If that outer rim sags it could cause a seam burst.

This is just me being a paranoid carpenter but Id put a cross joist diagonally on the top side as well to prevent moving/twisting as much as possible. While wood is very strong compressive-wise, the slightest wiggle on a high strain board can shift the direction of pressure and snap a board. More than likely won't happen but in the event of an earth quake you want to be sure.

Cross joist - Yes I plan on putting more 6 feel across front to back.
Composite shims - Great idea. Definitely worth it instead of using cheap left over wood cut shavings.

 

[pancakes]

I would do as suggested above and beef up the vertical support.
I would also like to point out that the horizontal boards are only attached from the side while they hold the vertical 2x6 in position they do nothing for actual support.
The addition of other vertical support placed underneath the horizontal will go a long way in adding strength.
I would also install some X bracing to prevent any shifting from side to side in both directions.
Edit:
So I pretty much second what Blakewater
said already.

Beef up vertical and horizontal boards - check.

What is everyone's thoughts about adding Galvanized face mount joist hangers for the 2x6 diagonal bracing? At 88cents ea. not bad for additional piece of mind added to the two 9x3" construction screws x2 from each side of the outer top and bottom rims. Think I will do it.

 

[Blakewater]

Hangers are always a good option for anything that wont be handling the actual strain so I suggest them. I also suggest putting a piece of 3/4 plywood over the entire top and then 3/4" insulation foam board on top of that. It will help evenly distribute all the weight and if your tanks going to be acrylic it will allow the bottom panel to bow to take stress off the corners