Anyone a structual engineer?

[Nuuze]

I need some assistance on how to properly reinforce my floor for plans of a 210G tank. Currently there is a 79G in place.

Interestingly my current home only has supports running across the center of the house perpendicular of the joists. Unlike homes I been under in the past there were supports or jacks every few feet of the entire floorplan. I did notice a different joist design. Older designs I seen were just straight solid joists where mine looks like a truss type joist design.

Here is a quick drawing of the floorplan.

Access hatch

Truss type joist

 

[Nuuze]

Few more pics...

Joists are 24" apart.

The back wall where the tank is sits in front of is right on top of the cement support underneath. I'm guessing a main support for the house and 2nd floor.

Other side of the house

 

[brianbigoats]

mike
try posting on the large tank fourm

 

[Nuuze]

Yeah, I found some info there, thanks.

 

[Nuuze]

http://reefcentral.com/forums/showthread.php?threadid=1308371

 

[WarrenG]

Those are some interesting joists, but they are designed to span much longer than the old solid wood type of joist, and your joists are much less likely to warp or twist than single pieces of solid wood.

I'm a bit confused by your drawing and explanation of the locations, but if your new tank will rest on the floor that is directly over (or adjacent to) the cement foundation wall, and the weight is distributed to 3 joists you should be fine. Even two feet out from the foundation wall the floor is very well-supported.

My own house is custom, and the engineer and I discussed how to support my 150g tank. We have engineered floor I-joists throughout the house (16-foot spans with no flex, and not heavy). The tank is located 1-5 feet from a concrete foundation wall on two joists and it is fine there.

 

[Nuuze]

It won't be directly over the cement wall bu right next to it. The wall behind the existing tank is directly over the cement support.

I'll have to get under again and measure exactly where the tank will be and how many joists.

 

[WarrenG]

I think you'll be fine. You could reinforce those joists back to the concrete wall. I'd do it by nailing 3/4 plywood sheets to the sides of those trusses. Nail with 8d or 10d nails every 6 inches. Then the trusses/joists will be super strong.

 

[Nuuze]

Thanks WarrenG!

How big of a plywood sheet or how far past the depth of the tank?

 

[WarrenG]

You can cut the plywood so that it's the same as the height of the truss, is that about 15 inches? And then it make it 4 feet long. Nail it on to each side of the truss (nailed to the edges of the 2x6's) about a foot or so beyond the front of your tank and back to about a foot on the other side of that concrete wall. If it's hard to get at, you could just put the plywood on one side of each of 3 trusses/joists.

It's most important that you nail the plywood to both horizontal members, (the one that has the flooring nailed/glued to it, and the other one that rests on the concrete wall).

You can do this with one sheet of plywood and Lowes/HD will even cut it for you for about 50 cents per cut. So for about $30 total those trusses will be strong enough to park a truck on.

 

[Nuuze]

Sounds easy enough WarrenG.

Is there a nailer for these types of nails(8d or 10d )? Do you think it would be easier if I can rent a nail gun to nail the plywood?

 

[kevin95695]

8 penny nails are big. Them are regular framin' nails, there. If you can figure out how to wrangle a nail gun down there, even better. I wouldn't want to hammer a bunch in confined spaces.

 

[Nuuze]

I have an air compressor, just don't know too much about which nails can be used with which nailers. I've also seen nailers that run on some gas. I would hate to nail a row of nail laying on moist dirt sideways. There's 24" between joists.

Also depending on price, I may also add a 5-6 foot 2x6 perpendicular of the joists about 3 feet from the cement wall on two jacks or cement blocks to reduce floor bounce when the kids place Wii in the room.

 

[WarrenG]

You can rent a "framing" nail gun for about $35/d I think. They will sell you nails too, at kind of a high price.

I'd use a hot-dipped galvanized, flat head nails (framing nailers only accept flat heads) at 2.5-3" long. (Standard sizes). You can buy a small box at Lowes for $30/1000 nails. Make sure you get the style of nails that will fit the nailer you have.

Wear some ear protection since you're in an enclosed space, and of course, safety glasses. Practice before you crawl under there.

Nail guns are my favorite tools. I don't know how people built houses without them.

If you add the perpendiculars, you'll find an appropriate Simpson bracket at Lowes/HD. You'll have to use hand-nailing to put the nails into the little holes, but the brackets are the way to go.

Since you are still within 5-7 feet of the concrete wall I think the plywood reinforcement would be easier and just as effective as adding those perpendiculars. You can do the 4-foot lengths of plywood, and then check for floor bounce. Then add another 2-3 feet if you think it's needed.

 

[jtarmitage]

I don't know about that! When his kids are playing the wii now, the waves are rockin in his 79g. I'd add the extra supports and not worry about it again.

 

[WarrenG]

I didn't realize wii offered Sumo Wrestling!

 

[Nuuze]

Man, that was some hard work! Glad my brother was able to help!

We used 3/4" plywood to sandwich the sides of the 4 joist. 11" high and 4' long with 3 1/2" screws.

Once the boards were in place we also used 4 screw type jacks to reduce floor bounce on a 2x6 and 12" pavers dug 4" down. Now imagine doing that laying sideways in mud type dirt.
I couldn't of done this all without help from my brother. Thanks Bro!

 

[WarrenG]

Yes, but the most important question, how is the floor handling the Wii sessions?



p.s. Now you know why pest inspection guys get paid relatively high wages.

 

[Nuuze]

There's almost no floor bounce now with me jumping in front of the tank half full. Earlier I could make ripples. I'm glad I did this. Thanks for the pointers WarrenG. I confirmed what you said with framers and builders and they pretty much said the same you did.

 

[WarrenG]

You're welcome, but I confess, there are engineers throughout my family, including my brother who designs large bridges. We have discussed trusses on many occasions when my house was being built and then his. We have some "interesting" ceilings in our house with some long spans, so I learned a lot about trusses then. And we used the interesting "I-Beam" floor joists that are so light but so strong when glued and nailed to the underside of the sub-floor.

So... on to the big tank!