Modifying shelf to hold 40G Breeder

[R_C]

Hello all,
I'm in the process of making this 40g breeder into an AIO tank. I would like to put in on the shelf that my 20G long is. Unfortunately I know that it will not hold the weight.

I know what I ultimately need to do, but I am asking for opinion/inputs.
The shelf is made up of just 1x4 frame and 1/2 inch OSB with sheet rock for top. Hollow in the inside.

I would like to brace the shelf to hold the weight without destroying the shelves and area.

Here is the spot where I want it to go.

Let them fly!

 

[Brew12]

Why do you think the shelf wouldn't hold the weight?

 

[R_C]

Why do you think the shelf wouldn't hold the weight?

Because it is only 1/2 OSB and it is hollow

This is what the inside looks like.

 

[redfishbluefish]

I have no problem with the 1 x 4 frame, assuming it is resting on jack studs (or jack 1 x 4's)(Do not rely on screws or nails to hold the weight of the shelf). The issue I have is with the use of OSB and sheetrock as a "top" material. I consider both of these materials water soluble!

Add a couple cross member 1 x 4 supports to that frame, top it with 3/4 plywood and then with whatever water resistant top you want....and you'll be good to go.

 

[R_C]

From what I can see. It is not really resting on anything at all. The frame is held on by nails (I think). There are no stud below the frame at all.

 

[Brew12]

I have no problem with the 1 x 4 frame, assuming it is resting on jack studs (or jack 1 x 4's)(Do not rely on screws or nails to hold the weight of the shelf). The issue I have is with the use of OSB and sheetrock as a "top" material. I consider both of these materials water soluble!

Add a couple cross member 1 x 4 supports to that frame, top it with 3/4 plywood and then with whatever water resistant top you want....and you'll be good to go.

Completely agree. I would even say you could go with 1/2"x4" framing on the inside if you want to keep it slimmer. You would be amazed at how much weight you could support that way.

 

[R_C]

Ok, so I can fully understand:
1) add some cross members to the hollow portion of the shelf.
2) Secure them with nails/screws
3) add a 3/4 inch top with water proofing material.

 

[redfishbluefish]

The drawing / explanation above looks good.

From what I can see. It is not really resting on anything at all. The frame is held on by nails (I think). There are no stud below the frame at all.

But this does not look good. You don't want to rely on a couple nails to hold all that weight. Ideally you want jack studs (that could be 1 by) going from the frame to the floor.....think of them as legs that directly support the shelf. It doesn't appear that that will be an easy add. Here's a thought that comes with no guarantee.....years ago we use to secure decks to houses using lag screws. They are no longer allowed....too many decks literally fell off the houses....need to bolt the header to the house now. Again, I'll repeat, no guarantee, but at every stud, where the frame crosses, pre-drill two holes and put in four inch lag screws...and use a washer on the lag as well. I don't recommend this, but it's certainly better than nails!

EDIT TO ADD: Above recommendation assumes a conventional stick frame constructed house (wood 2x4 construction), for the lags to grab hold.

 

[Dom]

So... a gallon of seawater weighs approximately 8.5 pounds. Multiply that by your 20 gallon long and you have a shelf that currently is supporting 170 pounds, give or take allowing for water displacement by live rock, substrate, inhabitants and anything else within the water column.

Your new tank is twice the size, so twice the weight. Your shelf needs to support approximately 340 pounds, give or take, taking into consideration the same displacement as the 20 gal.

This is a considerable amount of weight to support.

Personally, I would cleat legnths of 2x4 along the sides and back of the entire shelf length. Properly fastened to the walls and with a piece of 3/4 inch ply on top should be ample support.

If you don't mind my saying so; you don't have much going on in that space other than the tank. Why not relocate the remaining items, remove the shelves and build a nice stand to fit in the space?

 

[R_C]

If you don't mind my saying so; you don't have much going on in that space other than the tank. Why not relocate the remaining items, remove the shelves and build a nice stand to fit in the space?

I don't mind that at all. I was trying not to do all that extra work if there was another way.
Ultimately I think I'm going to have to go that route, if I want to do it "right".