Platform engineering: home made stand structural advice

[Scott.h]

I've decided to finish off my basement. I'm building a 90 into a wall so one side of the tank faces the bedroom and the other side faces the family room. The tank is currently sitting on a home made stand that is strong and straight, however do the it's new height not being high enough to clear the back of the couch I've decided to frame the two walls like Windows, slide the tank into its new spot.
My concern is two fold. I'm guessing the tank without rock is going to weigh about 900 lbs, so over time I'm wanting it to be square to prevent future leaks in the silicone. Outside wall to outside wall will be 18.25 inches. This leaves a span of 11.25 inches that I'm needing to fill with probably another 2x4 In-between depth wise. I'm guessing just topping it with 3/4" ply would might flex over time depth wise. Really my biggest concern is this new wall isn't as straight and square as a stand would be, and it's pretty hard to shim a pair of walls, along with the the in-between space to make everything perfectly straight. The concrete floor beneath is extremely unlevel, and construction 2x4's aren't perfect either. Would joining the two walls together with a 2x4 depth wise, (keep in mind Id have to go through 3.5 inches at each end 2x4) ,screwing plywood down, and maybe adding 1/2 of styrofoam underneath the tank be sufficient to perfectly distribute the weight, as well as make it level?

I hope that makes sense. Just getting ready to build the second wall now.

 

[cromag27]

Is this tank acrylic or glass? flat bottom or plastic trim?

I despise 2x4s for stands but your build is different in that it's an in-wall. whenever using 2xs I recommend you use a planer and jointer to make them even and level. shim under the back of the frame to make it level if the concrete is way off. I'd use composite shims.

 

[Scott.h]

Glass with plastic trim

Is this tank acrylic or glass? flat bottom or plastic trim?

I despise 2x4s for stands but your build is different in that it's an in-wall. whenever using 2xs I recommend you use a planer and jointer to make them even and level. shim under the back of the frame to make it level if the concrete is way off. I'd use composite shims.

 

[cromag27]

You don't need plywood on top, unless you're really worried the top 2xs aren't completely flat and level.

Glass with plastic trim

 

[Scott.h]

You don't need plywood on top, unless you're really worried the top 2xs aren't completely flat and level.

yeah I'm not sure. I have the walls up but I have to level the walls, bolt everything together and throw a level on it. In-between the walls I think I'll post a support up in the 18 inch section. I bought some sill plate foam I think I'll run under the walls as well as under the tank and I may use a 1/2 inch sheet of plywood too. That's about all I can do. I was thinking if I used 1/2 thick styrofoam on top of the plywood it would crush to disperse the weight more evenly. It's a good think God didn't have me build the ark, that's all I know.

 

[cromag27]

Do not use foam with a plastic trim tank. foam is for flat bottom glass tanks only. a sheet of 3/4" is all you need.

 

[Scott.h]

Do not use foam with a plastic trim tank. foam is for flat bottom glass tanks only. a sheet of 3/4" is all you need.

if it's bad I guess I could always pull the 2x4 back up and use some door shims. We'll see what the level says.
Have yo ever drilled rock? With being able to look through both sides I'm thinking of stacking rocks in the center but boring a hole through the center of the rocks and sliding a piece of pvc through the center to keep them put. I'm not sure what kind of a bit I'd use at 1" masonry"? Never done it.

 

[cromag27]

I have drilled rock. I just used an old, regular bit. you don't want to chop up the rock too much. I also used 1/2" acrylic rods.

 

[JasReef]

You can get cheap masonry bits at Harbor Freight. That is what I used and they work perfect for drilling the rock.

 

[Scott.h]

Harbor freight stocks big sized bits?

Where did you get the acrylic rods?

 

[cromag27]

http://www.tapplastics.com/product/plastics/plastic_rods_tubes_shapes/acrylic_rods/147

 

[ShinerMaginer]

Do not use foam with a plastic trim tank. foam is for flat bottom glass tanks only. a sheet of 3/4" is all you need.

I'm currently building an in wall 200DD, and was actually trying to find info on this. I have a 1" piece right now, and it felt like overkill. If the platform is level, you think I don't need it?

Great build!

 

[cromag27]

For acrylic, none needed. for glass, 3/4". nothing bad would happen if you used 1" though.

I'm currently building an in wall 200DD, and was actually trying to find info on this. I have a 1" piece right now, and it felt like overkill. If the platform is level, you think I don't need it?

Great build!

 

[ShinerMaginer]

Everything I've read so far says that my tank (with the standard trim on the bottom and top, so "floating" design) shouldn't have foam. I only get one chance not to screw this up, so not sure what to do. The platform is very level, shimmed and built the same way as a floor. It's not shifting anywhere, so thinking I'm going to just put it on the stand directly.

 

[Scott.h]

One inch seems like a lot of flex to me. But I'm not sure. I ended up putting a line of foam under the plywood, screwing the plywood through the foam, then putting the tank directly on the plywood. My thought was that it still has a chance to find its own place while being firm to the tank, as plywood still flexes some. Weather or not it leaks over time is yet to be know. Hopefully not.