Stand center brace

sandmanfd · Sep 3, 2023

Hello all, just built a stand for my 120g. It’s 48x24x24. Stand is all 2x4s and I put two layers of 3/4” plywood on top part. Wanted to know if I could get away without a center brace on stand.

Thanks

TangerineSpeedo · Sep 3, 2023

Yes, you would need to face the front and back with 3/4 marine plywood. You also need to glue the Ply not just nail it. For the front you can cut out for the doors. But do cut the front out of one continuous piece, with at least 6 inches above the doors.

Kodski · Sep 3, 2023

So in order to eliminate the center brace, the idea is to make sure the top beam does not deflect. The type of wood and how you use it is very important in this case. In houses you'll see 2x10's and 2x12's for beams in the same orientation as you have your 2x4 beam. In terms of dimensional lumber, the wider the wood, the more weight it will carry before deflecting. When trying to hold a lot of weight, a doubled beam is used. When even that cannot carry enough weight without deflecting, a special beam made of orientated strand boar, aka OSB is used. OSB will carry more weight without deflecting due to the direction of the wood grain. When wood grain is in a linear direction, as such with dimensional lumber, it is much easier to flex. When the wood grain is in all different directions, it becomes much more difficult to flex. Unfortunately the way you used the plywood doesn't utilize the woods strength. You would have been better off cutting strips of it and gluing it to your beam much like what TangerineSpeedo is suggesting. When utilized appropriately, plywood is much, much stronger than dimensional lumber, because the wood grain isn't all in one direction. In fact, when I built a stand for my 80 gallon tank which is the same footprint as your 120 gal, I only used plywood.

Here is a picture of said stand. I would easily trust this stand to take 4-5x's the weight that its currently holding.

All of that being said, the best way with your current structure to achieve your goal, is to remove the center braces from the top and add another 2x4 to your existing beam. This will double the load capacity of your beam and will be strong enough to minimize deflection with the weight of your tank. Personally, while following TangerineSpeedo's plywood idea will definitely increase the weight capacity of your beam, I think doubling it up would just be a better and stronger option which will let you skin the stand however you want to.

sandmanfd · Sep 3, 2023

Thanks for the input guys, tank is already up I guess I’ll just have to go with center brace. All pieces have already been glued and nailed for 3 months now